An Augustinian Monk working in Austria (today part of the Czech Republic). Had training in chemistry, physics & mathematics.

Size: px
Start display at page:

Download "An Augustinian Monk working in Austria (today part of the Czech Republic). Had training in chemistry, physics & mathematics."

Transcription

1 Mendelian genetics At the beginning of the last section, we mentioned that while you may resemble your parents, you're not an exact copy. Knowing what we do about mitosis and meiosis, we're now ready to figure this out. Inheritance has a long history. The ancient Greeks were some of the first to give it serious thought; they has some interesting ideas (e.g., blending), but it wasn't until the mid 1800's that real progress was made. Gregor Mendel An Augustinian Monk working in Austria (today part of the Czech Republic). Had training in chemistry, physics & mathematics. Worked with garden peas to deduce how inheritance worked. Was experienced with these from childhood - AND he could control their breeding (i.e., which plant bred with which). Picked seven characteristics of pea plants to study how these characteristics were passed on from one generation to the next [OVERHEAD, fig. 9.2D, p. 155]. Started with pure breeding strains of plants For example, made sure he started with a plant that only produced purple flowers though several generations. Started by hybridizing these pure-bred strains. For example, what would happen if he crossed a plant that produced purple flowers with one that produced white flowers? Some terminology: P - parent generation F 1 - first offspring generation F 2 - offspring from F 1 etc. Single characteristics (in pea plants) [OVERHEAD, fig. 9.3A, p. 156]: Starting with plants that only produced purple flowers (pure strain purple) and plants that only produced white flowers (pure strain white): Mendel discovered that the F 1 generation was all purple (notice we're not saying they were a pure strain of purple).

2 What happened to white? Notice also that Mendel disproved the blending hypothesis that some people were considering (as far back as the Greeks). Mendel took the F 1 generation and bred it with itself (i.e., crossed plants from F 1 with other plants from F 1 ). Result was F 2, but in F 2, approximately ¾ of the flowers were purple, and ¼ were white. What was going on? Where did white suddenly come from? This should be no surprise - some of the characteristics about you may quite possibly come from your grand parents, and not your parents. Nevertheless, what's happening? Mendel developed four hypotheses based on his research. Mendel's four hypotheses: 1) There are alternative forms of heritable factors (what we now call genes). Alternative forms are called alleles. In our flowers we have two alleles for color, purple and white. 2) Each individual inherits two copies of these alleles. These may be two of the same (e.g., two alleles for purple), or two different ones (one for white, one for purple). If an individual has two of the same alleles, it is termed homozygous If an individual has two different alleles, it is heterozygous. 3) If the two alleles are different (the individual is a heterozygote), then one of the alleles will determine the individual's appearance. This is the "dominant" allele. The other allele essentially has no effect on the individual, and is called recessive. Note that this hypothesis is not always true (more later). 4) a gamete (sperm or egg) carries only 1 allele for each trait (because alleles separate from each other during production of gametes (meiosis)). Sometimes known as the law of segregation. When gametes come together (fertilization), there are again two copies of each allele. Mendel's explanation of the observed events [OVERHEAD, fig. 9.3B, p. 156]: Using Mendel's first two hypotheses, we can say:

3 One of the parent flowers (P plants) has two purple alleles, The other has two white alleles Thus, the gametes from the P generation are either P (purple) or p (white). (Note that unfortunately your text uses P for both the P generation and the P (purple) allele - they mean two different things). All the offspring from the parents got one P (purple) and one p (white). Putting these together, we use hypothesis 3 and conclude that the reason all the F1 plants are purple is due to the fact that P (purple) is dominant. p (white) is recessive. When looking at two alleles where one is dominant and the other recessive, we often use capital letters for the dominant allele, and lower case letters for the recessive. Finally, we can also explain the F 2 generation. We know that all the F 1 generation must have one P and one p (they're all Pp). Half of the sperm from F 1 will be P, half p. Similarly, half of the eggs will be P, and half p. If we now combine eggs and sperm, we can get four possible results: Egg with P and sperm with p (Result = Pp) Egg with P and sperm with P (Result = PP) Egg with p and sperm with p (Result = pp) Egg with p and sperm with P (Result = Pp) The Punnett square illustrates a better way of doing this (we put all possible sperms on one side, and all possible eggs on the other) I either case, notice we now have: ¾ purple (both PP and Pp are purple), and ¼ white (pp) Tis finally explains Mendel's results for F 2. Notice that the phenotypes and genotypes are different [OVERHEAD, not in book]. Phenotype - the physical appearance of our organism (Due to genetic AND environmental effects, though we won't worry too much about environmental effects right now). Our phenotype ratio is 3 purple : 1 white (¾ purple, ¼ white).

4 Genotype - the genetic makeup of our organism Our genotype ratio is 1 PP : 2 Pp : 1 pp (or ¼ PP, ½ Pp, ¼ pp). Mendel noticed that all of his other characteristics also worked the same way. Incidentally, statisticians have proved that Mendel cheated a little with his results. His results were better than one would expect (his ratios were way too good). Nevertheless, he had the right ideas, and interpreted his data correctly (he just made it look a little better). Some final remarks on Mendel: He published his results, which were promptly forgotten (Darwin had a copy, but didn't know what to do with it). He tried some crosses with animals (bees), but had difficulty controlling the crosses. Eventually he was elected abbot, and after that spent most of his time administrating the monastery. Mendel's research was eventually re-discovered and acknowledged about the turn of the century (1900). Review of gene loci [OVERHEAD, fig. 9.4, p. 157] Where are these alleles? Alleles for a particular trait are at the same loci on homologous chromosomes. Remember that during meiosis I, our homologous chromosomes go their separate ways, so our alleles go their separate ways (which is why Mendel's hypothesis 4 works). Working with more than one trait at a time [OVERHEAD, fig. 9.5A, p. 158]. Often, when we look at more than one trait, it turns out these traits are on different chromosomes (not homologous pairs). For example: Seed color (yellow and green) and seed shape (round and wrinkled) Y (yellow) is dominant, and R (round) is dominant (Mendel deduced this from previous crosses). So if we now take an individual that's homozygous for yellow and round (YYRR) and cross with an individual that's homozygous for green and wrinkled (yyrr), as expected, all the offspring are: YyRr (yellow and round).

5 Probability: Testcrosses: The question becomes, what happens when we cross this F1 generation with itself (YyRr x YyRr)? Two possible results. If Y and R always go together, and y and r always go together, we expect the results on the left hand side of the figure. (Four possible genotypes, two possible phenotypes) On the other hand, if Y and R each do their own thing (Y doesn't care what R is doing and vice versa), we get the result on the right hand side of the figure. (Nine possible genotypes, four possible phenotypes). The results were consistent with the second hypothesis. Thus we have the law of independent assortment. This states that each pair of alleles segregates (separates) independently of every other pair [OVERHEAD, fig. 9.16, p. 171]. (For some silly reason your text puts this figure no where near the previous one). As it turns out, this is only true if the traits are on different chromosomes (i.e., on non-homologous chromosomes). There are situations where this obviously doesn't hold. (Not all traits are independent). Remember - this is why we get many different combinations of chromosomes in our gametes (fig. 9.16). Another example is coat color in Labrador retrievers [OVERHEAD, fig. 9.5B, p. 159] How can we find out if someone is PP (purple) or Pp (also purple)? A testcross can be used. Cross the individual with a homozygous recessive: If the individual is PP, all offspring will be purple (why?) If the individual is Pp, ½ of the offspring will be purple, the other half yellow. [OVERHEAD, fig. 9.6, p. 159] uses our labs as an example. Be aware that most of what we're doing can be modeled using the laws of probability. I would love to go through this material (I'm a statistician after all!), but I don't see how it adds much to the discussion. Most of the problems here or in lab can be solved using Punnett squares & logic.

6 Human genetic traits: [OVERHEAD, fig. 9.8A, p. 161] Freckles / no freckles Widow's peak / no widow's peak Free earlobe / attached earlobe Important: notice that a dominant trait does NOT mean it's more common (Purple kernels are dominant in corn - how much purple corn is there?) More on this soon (when we do Hardy-Weinberg). Some of these human traits can be diseases (this topic also introduces family trees ) [OVERHEAD, not in book] A deaf boy was born to two normal parents. Deaf is recessive (in this kind of deafness) [OVERHEAD, fig. 9.9A, p. 162]. Implies that both parents were heterozygous (only in that way could Jonathan have inherited two recessive alleles). Also, notice that Jonathan had deaf children. He only passed on ONE allele for deafness. The other must have come from his wife. Implies that one of his wife's parents must have been heterozygous, but we can't say which one. Many genetic diseases are caused by a single gene (and one defective allele). [OVERHEAD, table 9.9, p. 163] Most serious genetic diseases are recessive If a genetic disease is dominant, it usually is not passed on to the offspring. Children die before being able to pass on the disease, so the disease does not survive. Recessive diseases can be carried without ill effects by heterozygotes. These are often termed carriers. But some dominant genetic diseases exist: Huntington's disease Does not strike until middle age. The parents have already had children, so the disease can be passed on. Inbreeding often increases the incidence of the disease

7 Expansions / variations on Mendel. Briefly, related individuals are more likely to both be carriers, and so pass on the disease to their children. This is easy to see with siblings, but even with 1st or 2nd cousins, the probability is still higher than normal. One can actually calculate this using some of the probability we skipped over. Mendel's hypotheses and laws do not account for everything. Some common exceptions: Incomplete dominance In this case, neither allele is dominant. The individual has traits in between the two alleles. The result is often a blending of the characteristics of both parents. [OVERHEAD, fig. 9.11A, p. 166] Flowers are red, white, or pink. BUT, in F 2, we get back to pure white or red, which wouldn't happen if the old blending hypothesis were correct. Blending pink and pink should yield just more pink. Hypercholesterolemia is another example HH -> normal Hh -> cholesterol levels about twice normal hh -> very high cholesterol levels. There is also co-dominance, where both alleles are expressed - the difference between this and incomplete dominance is subtle. Co-dominance means both alleles are expressed (the result is not in between ). Blood groups are an example. A and B are both expressed - blood type AB is not a mix of types A and B. More than two alleles and more on blood types and co-dominance: Many traits can have more than two alleles. Blood groups are a good example. There are three alleles: Type A, type B, and type O. Types A and B are dominant to type O:

8 AO & AA are essentially the same BO and BB are essentially the same OO is the only way to be type O Types A & B are co-dominant. People have some blood cells with type A characteristics, and some blood cells with type B characteristics. Note that AB is not a blending of types A and B. The reason one has to be careful with blood transfusions [OVERHEAD, fig. 9.12, p. 167]: Types A have cell identifiers for type A. Type B has different cell identifiers and is attacked. The same goes for type B (type A cells are attacked). In type AB, the body knows about both types of cells, so neither is attacked. Type O has no cell identifiers, so type O can be given to anybody (types A, B, or AB do not recognize O (no identifiers), and do not attack it). On the other hand, type O individuals will recognize both types A and B as foreign (type O individuals don't recognize any cell identifiers, so all cell identifiers are considered foreign). O is the universal donor, AB the universal recpipient. This presentation is just a little different than the book, but they both wind up in the same place (the book might be marginally more accurate, this might be a little easier to understand). Pleiotropy Simply put, this is where one allele will have multiple effects. [OVERHEAD, fig. 9.13, p. 168] Sickle cell anemia is a good example. Notice that this (as mentioned) is also an example of incomplete dominance. Heterozygotes are generally normal but much more resistant to malaria. Their cells will sickle under poor oxygen conditions, or when attacked by the malaria parasite (and the infected cells get destroyed!). Homozygous individuals either:

9 Don't get sickle cell (but get malaria) Get sickle cell (which is often fatal) We may mention this again when we do evolution, but being heterozygote is a distinct advantage. Malaria kills 2/3 of a million people every year. It's a strange situation, since both homozygote conditions are at a disadvantage. Many genes can influence a single character (kind of the opposite of pleiotropy). [OVERHEAD, fig. 9.14, p. 169] Three genes all contribute to skin color (book mentions it's at least three, maybe more). Environmental influences: Dominant in each case contributes some pigment. We can go from 0 to 6 (7 levels) of pigment. Environmental influences can determine a lot about our appearance Exercise, diet, altitude, sunlight, etc. (Mendel used characteristics that were generally not influenced by the environment). Genetic testing: There are many tests that can determine if some of these genetic diseases are present. Specific disease causing alleles can be detected. Depending on what is found, a couple may decide not to have children, for example (if both parents are carriers for a nasty disease). We need to be careful we don't use this information to make decisions about getting life insurance, etc. See also section 9.10 for more on genetic testing and some of the ethical issues raised. Exceptions to the law of independent assortment If the genes we are considering are on the same chromosomes, then independent assortment may not work as Mendel described. [OVERHEAD, fig. 9.17, p. 172] Purple and long pollen are on the same chromosome.

10 Crossing PpLl x PpLl did not yield the expected ratio of 9:3:3:1 Instead we got almost our 3:1 ratio of 3 purple-long: 1 red-round. P and L are on the same chromosome, and p and l are on the same chromosome, so we get 3 dominant : 1 recessive (a typical monohybrid cross). These are also known as linked genes. Crossing over produced the few exceptions to our 3:1 ratio. Review: [OVERHEAD, fig. 9.18A, p. 173] Crossing over was first hypothesized working with fruit flies: [OVERHEAD, fig. 9.18C, p. 173] A fly that was known to be heterozygous for two different traits (body color and wing length) was crossed with a fly recessive for both traits (black body and vestigial wings). A dihybrid cross in which the genes are on different chromosomes (independent assortment) would produce a 1:1:1:1 ratio: ¼ gray, normal, ¼ gray, vestigial, ¼ black, normal, ¼ black, vestigial. Instead, most (but not all!) of the flies were gray, normal or black, vestigial. The hypothesis was developed that these genes are linked (i.e. on the same chromosome), but that some mechanism sometimes broke the linkage to produce the other two varieties. This some mechanism was later shown to be crossing over. It turns out, crossing over can be used to identify the location of genes (to map genes). The further apart to genes (on the same chromosome) are, the more likely it is that they will undergo crossing over. If two genes are far apart, there are many points between them where crossing over can occur. If two genes are close together, there are only a few points between them where crossing over can occur. Incidentally, all points on a chromosome are not equally likely to be involved in crossing over, but the general principle holds. The greater the distance, the more likely crossing over will occur between genes.

11 Sex and chromosomes So, by looking at how often genes recombine through crossing over, we can get an idea of how far genes are physically apart on the chromosome. [OVERHEAD, fig A & B, p. 174]. As described, for many animals, chromosomes determine sex. In humans, we use X and Y (named due to the shape of the chromosomes). XY -> male, XX -> female [OVERHEAD, fig B - E, p. 175]. Other systems: A gene on the Y chromosome codes for the development of testes. The exact process is not yet understood, XX -> female, XO -> male (where O means no chromosome) Found in some insects like grasshoppers. Note that in both the XY and XO systems it's the male that determines sex: Sperm can be either X or Y (humans), or X or O (some insects like grasshoppers). ZW -> female, ZZ -> male In some birds, fish, butterflies. Notice that it is the female that has two different chromosomes. Therefore, it's the female that determines sex: Eggs can be either Z or W, males can only make sperm with Z. Some insects use chromosome number: diploid --> female, haploid --> male Some animals (some turtles, crocodiles) have temperature determined sex: The temperature of their eggs determines if the individual will be male or female. There is lots of variation in determining sex. And, of course, many organisms are hermaphrodites (have male and female parts); for them this is irrelevant.

12 Sex linked traits If genes (alleles) are being carried on the sex chromosomes, strange things can happen. In humans, for example, the Y chromosome does not carry many genes. So if genetic information is being carried on the sex chromosomes, men get only one allele (from the X chromosome). Genes carried on the sex chromosomes are often referred to as sex linked. Let's take a look to see what can happen. We'll look at fruit flies (again). White eyes is a recessive trait. Further, it's carried on the sex chromosomes (fruit flies have a XY system for determining sex). We have: X R X R -> red female X R X r -> red female X r X r -> white female X R Y -> red male (notice males only have one allele) X r Y -> white male As you might expect, it's easier to get white males than white females. Three examples [OVERHEAD, fig B - D, p. 176]: Crossing X R X R with X r Y: ½ X R X r, ½ X R Y (All males must get X R from the mother) Crossing X R X r with X R Y ¼ X R X R, ¼ X R Y, ¼ X r X R, ¼ X r Y (Notice that only males can be white, for a female to be white, she MUST get X r from the father (the father does not have X r )).

13 Crossing X R X r with X r Y ¼ X R X r, ¼ X R Y, ¼ X r X r, ¼ X r Y (This time, the female offspring can get one X r from the mother and one X r from the father, so we do get white females). Due to this phenomenon, sex linked recessive traits show up more commonly in males than in females (males only need one recessive allele, females need two). If this trait is also a disease, this can have devastating consequences for males (they're more likely to get the disease). Red-green color blindness is more common in men One type of hemophilia is more common in men [OVERHEAD, fig. 9.22, p. 177] Duchenne muscular dystrophy is more common in men A disease that causes muscle weakening and loss of coordination. Often fatal by the early 20's (in age). All three diseases are more common in men because all three are carried on the sex chromosome (the X chromosome, not the Y).

Genetics & The Work of Mendel. AP Biology

Genetics & The Work of Mendel. AP Biology Genetics & The Work of Mendel Gregor Mendel Modern genetics began in the mid-1800s in an abbey garden, where a monk named Gregor Mendel documented inheritance in peas u used experimental method u used

More information

Meiotic Mistakes and Abnormalities Learning Outcomes

Meiotic Mistakes and Abnormalities Learning Outcomes Meiotic Mistakes and Abnormalities Learning Outcomes 5.6 Explain how nondisjunction can result in whole chromosomal abnormalities. (Module 5.10) 5.7 Describe the inheritance patterns for strict dominant

More information

Genetics & The Work of Mendel

Genetics & The Work of Mendel Genetics & The Work of Mendel 2006-2007 Gregor Mendel Modern genetics began in the mid-1800s in an abbey garden, where a monk named Gregor Mendel documented inheritance in peas used experimental method

More information

Genes and Inheritance

Genes and Inheritance Genes and Inheritance Variation Causes of Variation Variation No two people are exactly the same The differences between people is called VARIATION. This variation comes from two sources: Genetic cause

More information

8.1 Genes Are Particulate and Are Inherited According to Mendel s Laws 8.2 Alleles and Genes Interact to Produce Phenotypes 8.3 Genes Are Carried on

8.1 Genes Are Particulate and Are Inherited According to Mendel s Laws 8.2 Alleles and Genes Interact to Produce Phenotypes 8.3 Genes Are Carried on Chapter 8 8.1 Genes Are Particulate and Are Inherited According to Mendel s Laws 8.2 Alleles and Genes Interact to Produce Phenotypes 8.3 Genes Are Carried on Chromosomes 8.4 Prokaryotes Can Exchange Genetic

More information

Labrador Coat Color Similar to coat color in mice: Black lab is BxEx Yellow lab is xxee Chocolate lab is bbex Probable pathway:

Labrador Coat Color Similar to coat color in mice: Black lab is BxEx Yellow lab is xxee Chocolate lab is bbex Probable pathway: Honors Genetics 1. Gregor Mendel (1822-1884) German monk at the Augustine Abbey of St. Thomas in Brno (today in the Czech Republic). He was a gardener, teacher and priest. Mendel conducted experiments

More information

Genetics PPT Part 1 Biology-Mrs. Flannery

Genetics PPT Part 1 Biology-Mrs. Flannery Genetics PPT Part Biology-Mrs. Flannery In an Abbey Garden Mendel studied garden peas because they were easy to grow, came in many readily distinguishable varieties, had easily visible traits are easily

More information

Patterns of Inheritance. Game Plan. Gregor Mendel ( ) Overview of patterns of inheritance Determine how some genetic disorders are inherited

Patterns of Inheritance. Game Plan. Gregor Mendel ( ) Overview of patterns of inheritance Determine how some genetic disorders are inherited Patterns of Inheritance Game Plan Overview of patterns of inheritance Determine how some genetic disorders are inherited Gregor Mendel (8-88) Austrian monk responsible for developing the modern idea of

More information

Genetics & The Work of Mendel

Genetics & The Work of Mendel Genetics & The Work of Mendel 2006-2007 Gregor Mendel Modern genetics began in the mid-1800s in an abbey garden, where a monk named Gregor Mendel documented inheritance in peas used experimental method

More information

Genes and Inheritance (11-12)

Genes and Inheritance (11-12) Genes and Inheritance (11-12) You are a unique combination of your two parents We all have two copies of each gene (one maternal and one paternal) Gametes produced via meiosis contain only one copy of

More information

Patterns of Inheritance

Patterns of Inheritance 1 Patterns of Inheritance Bio 103 Lecture Dr. Largen 2 Topics Mendel s Principles Variations on Mendel s Principles Chromosomal Basis of Inheritance Sex Chromosomes and Sex-Linked Genes 3 Experimental

More information

Introduction Chapter Experimental genetics began in an abbey garden. 9.2 Experimental genetics began in an abbey garden

Introduction Chapter Experimental genetics began in an abbey garden. 9.2 Experimental genetics began in an abbey garden Introduction Chapter 9 Dogs are one of man s longest genetic experiments. Over thousands of years, humans have chosen and mated dogs with specific traits. Resulting in a diverse array of dogs with distinct

More information

Mendelian Genetics. Biology 3201 Unit 3

Mendelian Genetics. Biology 3201 Unit 3 Mendelian Genetics Biology 3201 Unit 3 Recall: Terms Genetics is a branch of biology dealing with the principles of variation and inheritance in animals and plants. Heredity the passing of traits from

More information

Chapter 10 Notes Patterns of Inheritance, Part 1

Chapter 10 Notes Patterns of Inheritance, Part 1 Chapter 10 Notes Patterns of Inheritance, Part 1 I. Gregor Mendel (1822-1884) a. Austrian monk with a scientific background b. Conducted numerous hybridization experiments with the garden pea, Pisum sativum,

More information

11.1 The Work of Mendel

11.1 The Work of Mendel 11.1 The Work of Mendel Originally prepared by Kim B. Foglia Revised and adapted by Nhan A. Pham Objectives Describe Mendel s classic garden pea experiment. Summarize Mendel s conclusion about inheritance.

More information

UNIT 6 GENETICS 12/30/16

UNIT 6 GENETICS 12/30/16 12/30/16 UNIT 6 GENETICS III. Mendel and Heredity (6.3) A. Mendel laid the groundwork for genetics 1. Traits are distinguishing characteristics that are inherited. 2. Genetics is the study of biological

More information

General Biology 1004 Chapter 9 Lecture Handout, Summer 2005 Dr. Frisby

General Biology 1004 Chapter 9 Lecture Handout, Summer 2005 Dr. Frisby Slide 1 CHAPTER 9 Patterns of Inheritance PowerPoint Lecture Slides for Essential Biology, Second Edition & Essential Biology with Physiology Presentation prepared by Chris C. Romero Neil Campbell, Jane

More information

Mendel and Heredity. Chapter 12

Mendel and Heredity. Chapter 12 Mendel and Heredity Chapter 12 12.1 Objectives: 1.) summarize the importance of Mendel s experiments 2.)Differentiate between genes and alleles. 3.) Explain that alleles determine what physical traits

More information

GENETICS NOTES. Chapters 12, 13, 14, 15 16

GENETICS NOTES. Chapters 12, 13, 14, 15 16 GENETICS NOTES Chapters 12, 13, 14, 15 16 DNA contains the genetic code for the production of PROTEINS. A gene is a segment of DNA, which consists of enough bases to code for many different proteins. The

More information

Objectives. ! Describe the contributions of Gregor Mendel to the science of genetics. ! Explain the Law of Segregation.

Objectives. ! Describe the contributions of Gregor Mendel to the science of genetics. ! Explain the Law of Segregation. Objectives! Describe the contributions of Gregor Mendel to the science of genetics.! Explain the Law of Segregation.! Explain the Law of Independent Assortment.! Explain the concept of dominance.! Define

More information

For a long time, people have observed that offspring look like their parents.

For a long time, people have observed that offspring look like their parents. Chapter 10 For a long time, people have observed that offspring look like their parents. Even before we knew about genes, people were breeding livestock to get certain traits in the offspring. They knew

More information

By Mir Mohammed Abbas II PCMB 'A' CHAPTER CONCEPT NOTES

By Mir Mohammed Abbas II PCMB 'A' CHAPTER CONCEPT NOTES Chapter Notes- Genetics By Mir Mohammed Abbas II PCMB 'A' 1 CHAPTER CONCEPT NOTES Relationship between genes and chromosome of diploid organism and the terms used to describe them Know the terms Terms

More information

Chapter 11 introduction to genetics 11.1 The work of Gregor mendel

Chapter 11 introduction to genetics 11.1 The work of Gregor mendel Chapter 11 introduction to genetics 11.1 The work of Gregor mendel What is inheritance? Two uses of the word inheritance Things that are passed down through generations Factors we get from our parents

More information

Biology. Chapter 13. Observing Patterns in Inherited Traits. Concepts and Applications 9e Starr Evers Starr. Cengage Learning 2015

Biology. Chapter 13. Observing Patterns in Inherited Traits. Concepts and Applications 9e Starr Evers Starr. Cengage Learning 2015 Biology Concepts and Applications 9e Starr Evers Starr Chapter 13 Observing Patterns in Inherited Traits Cengage Learning 2015 Cengage Learning 2015 After completing today s activities, students should

More information

Genetics and Heredity Notes

Genetics and Heredity Notes Genetics and Heredity Notes I. Introduction A. It was known for 1000s of years that traits were inherited but scientists were unsure about the laws that governed this inheritance. B. Gregor Mendel (1822-1884)

More information

Ch 10 Genetics Mendelian and Post-Medelian Teacher Version.notebook. October 20, * Trait- a character/gene. self-pollination or crosspollination

Ch 10 Genetics Mendelian and Post-Medelian Teacher Version.notebook. October 20, * Trait- a character/gene. self-pollination or crosspollination * Trait- a character/gene shape, * Monk in Austria at age 21 * At 30, went to University of Vienna to study science and math * After graduating he returned to the monastery and became a high school teacher

More information

Fundamentals of Genetics

Fundamentals of Genetics Fundamentals of Genetics For thousands of years people have known that living things somehow pass on some type of information to their offspring. This was very clear in things that humans selected to breed

More information

Mendelian Genetics: Patterns of Inheritance

Mendelian Genetics: Patterns of Inheritance Mendelian Genetics: Patterns of Inheritance A Bit on Gregor Mendel Born to a poor farming family in what is now part of Czech Republic Attended Augustinian monastery (1843) Became an excellent teacher

More information

Genetics. The study of heredity. Father of Genetics: Gregor Mendel (mid 1800 s) Developed set of laws that explain how heredity works

Genetics. The study of heredity. Father of Genetics: Gregor Mendel (mid 1800 s) Developed set of laws that explain how heredity works Genetics The study of heredity Father of Genetics: Gregor Mendel (mid 1800 s) Developed set of laws that explain how heredity works Father of Genetics: Gregor Mendel original pea plant (input) offspring

More information

Mendel and Heredity. Chapter 12

Mendel and Heredity. Chapter 12 Mendel and Heredity Chapter 12 Objectives: 1.) Differentiate between genotype and phenotype 2.)Differentiate between genes and alleles. 3.) Differentiate between dominant and recessive alleles. 4.) Explain

More information

Extra Review Practice Biology Test Genetics

Extra Review Practice Biology Test Genetics Mendel fill in the blanks: Extra Review Practice Biology Test Genetics Mendel was an Austrian monk who studied genetics primarily using plants. He started with plants that produced offspring with only

More information

Patterns of Heredity Genetics

Patterns of Heredity Genetics Patterns of Heredity Genetics DO NOW Hand in outlines (my desk) Pick up tests from back table and review them. We will be going over the zipgrade and the short answer together. Save your questions for

More information

HEREDITY. Heredity is the transmission of particular characteristics from parent to offspring.

HEREDITY. Heredity is the transmission of particular characteristics from parent to offspring. INHERITANCE IN LIFE HEREDITY Heredity is the transmission of particular characteristics from parent to offspring. Mendel presented completely new theory of inheritance in the journal Transactions of the

More information

Unit 7 Section 2 and 3

Unit 7 Section 2 and 3 Unit 7 Section 2 and 3 Evidence 12: Do you think food preferences are passed down from Parents to children, or does the environment play a role? Explain your answer. One of the most important outcomes

More information

Gregor Mendel. What is Genetics? the study of heredity

Gregor Mendel. What is Genetics? the study of heredity Gregor Mendel What is Genetics? the study of heredity Gregor Mendel s Peas Pollen: plant s sperm Egg Cells: plants reproductive cells Fertilization: joining of pollen + egg cells develops into embryo in

More information

GENETICS PREDICTING HEREDITY

GENETICS PREDICTING HEREDITY GENETICS PREDICTING HEREDITY INTRODUCTION TO GENETICS Genetics is the scientific study of heredity Heredity is essentially the study of how traits are passed from parents to their offspring. GREGOR MENDEL

More information

12 MENDEL, GENES, AND INHERITANCE

12 MENDEL, GENES, AND INHERITANCE 12 MENDEL, GENES, AND INHERITANCE Chapter Outline 12.1 THE BEGINNINGS OF GENETICS: MENDEL S GARDEN PEAS Mendel chose true-breeding garden peas for his experiments Mendel first worked with single-character

More information

Chapter 13: Patterns of Inheritance

Chapter 13: Patterns of Inheritance Chapter 13: Patterns of Inheritance 1 Gregor Mendel (1822-1884) Between 1856 and 1863 28,000 pea plants Called the Father of Genetics" 2 Site of Gregor Mendel s experimental garden in the Czech Republic

More information

VOCABULARY. TRAITS a genetic (inherited) characteristic. HEREDITY The passing of traits from parent to offspring

VOCABULARY. TRAITS a genetic (inherited) characteristic. HEREDITY The passing of traits from parent to offspring VOCABULARY TRAITS a genetic (inherited) characteristic HEREDITY The passing of traits from parent to offspring GENETICS the branch of biology that studies heredity (inherited traits) 1 Gregor Mendel Who?

More information

MENDELIAN GENETICS. Punnet Squares and Pea Plants

MENDELIAN GENETICS. Punnet Squares and Pea Plants MENDELIAN GENETICS Punnet Squares and Pea Plants Introduction Mendelian laws of inheritance are statements about the way certain characteristics are transmitted from one generation to another in an organism.

More information

Name Class Date *PACKET NOTES & WORKSHEETS LAB GRADE

Name Class Date *PACKET NOTES & WORKSHEETS LAB GRADE Name Class Date *PACKET NOTES & WORKSHEETS LAB GRADE MEIOSIS is specialized cell division resulting in cells with the genetic material of the parents Sex cells called have exactly set of chromosomes, this

More information

Genetics. F 1 results. Shape of the seed round/wrinkled all round 5474 round, 1850 wrinkled 2.96 : 1

Genetics. F 1 results. Shape of the seed round/wrinkled all round 5474 round, 1850 wrinkled 2.96 : 1 Genetics Genetics is the study of heredity and variations. Its expression influences the functions of individuals at all levels. Evidently, this branch of biology involves the study of molecules, cells,

More information

Biology Unit 7 Genetics 7:1 Genetics

Biology Unit 7 Genetics 7:1 Genetics Biology Unit 7 Genetics 7:1 Genetics Gregor Mendel: Austrian monk Studied the inheritance of traits in pea plants His work was not recognized until the 20 th century Between 1856 and 1863, Mendel cultivated

More information

Genetics and heredity. For a long time, general ideas of inheritance were known + =

Genetics and heredity. For a long time, general ideas of inheritance were known + = Mendelian Genetics Genetics and heredity For a long time, general ideas of inheritance were known + = + = What was really lacking was a quantitative understanding of how particular traits were passed down

More information

Name Class Date. Review Guide. Genetics. The fundamental principles of genetics were first discovered by. What type of plant did he breed?.

Name Class Date. Review Guide. Genetics. The fundamental principles of genetics were first discovered by. What type of plant did he breed?. Name Class Date Review Guide Genetics The fundamental principles of genetics were first discovered by. What type of plant did he breed?. True-breeding parental plants are called the generation. Their hybrid

More information

Chapter 9. Patterns of Inheritance. Lecture by Mary C. Colavito

Chapter 9. Patterns of Inheritance. Lecture by Mary C. Colavito Chapter 9 Patterns of Inheritance PowerPoint Lectures for Biology: Concepts & Connections, Sixth Edition Campbell, Reece, Taylor, Simon, and Dickey Copyright 2009 Pearson Education, Inc. Lecture by Mary

More information

Patterns of Heredity - Genetics - Sections: 10.2, 11.1, 11.2, & 11.3

Patterns of Heredity - Genetics - Sections: 10.2, 11.1, 11.2, & 11.3 Patterns of Heredity - Genetics - Sections: 10.2, 11.1, 11.2, & 11.3 Genetics = the study of heredity by which traits are passed from parents to offspring Page. 227 Heredity = The passing of genes/traits

More information

Chapter 6 Heredity The Big Idea Heredity is the passing of the instructions for traits from one generation to the next.

Chapter 6 Heredity The Big Idea Heredity is the passing of the instructions for traits from one generation to the next. Chapter 6 Heredity The Big Idea Heredity is the passing of the instructions for traits from one generation to the next. Section 1 Mendel and His Peas Key Concept The work of Gregor Mendel explains the

More information

Laws of Inheritance. Bởi: OpenStaxCollege

Laws of Inheritance. Bởi: OpenStaxCollege Bởi: OpenStaxCollege The seven characteristics that Mendel evaluated in his pea plants were each expressed as one of two versions, or traits. Mendel deduced from his results that each individual had two

More information

OCTOBER 21 Unit 5 Heredity 1. What is Heredity

OCTOBER 21 Unit 5 Heredity 1. What is Heredity OCTOBER 21 Unit 5 Heredity 1. What is Heredity the passing on of physical or mental characteristics genetically from one generation to another. Agenda 1. Warm-up 2. Mendlian Notes pg 5-6 3. Lets Practice

More information

Genetics and Heredity

Genetics and Heredity Genetics and Heredity History Genetics is the study of genes. Inheritance is how traits, or characteristics, are passed on from generation to generation. Chromosomes are made up of genes, which are made

More information

Downloaded from Chapter 5 Principles of Inheritance and Variation

Downloaded from  Chapter 5 Principles of Inheritance and Variation Chapter 5 Principles of Inheritance and Variation Genetics: Genetics is a branch of biology which deals with principles of inheritance and its practices. Heredity: It is transmission of traits from one

More information

Genetics. Why do offspring resemble their parents? What role can technology play in genetics? Let s explore the answers to these questions.

Genetics. Why do offspring resemble their parents? What role can technology play in genetics? Let s explore the answers to these questions. In a monastery garden, a curious monk discovered some of the basic principles of genetics. The monk, Gregor Mendel (1822 1884), laid the groundwork for the study of genetics, which has advanced our understanding

More information

Mendelian Genetics. You are who you are due to the interaction of HEREDITY and ENVIRONMENT. ENVIRONMENT: all outside forces that act on an organism.

Mendelian Genetics. You are who you are due to the interaction of HEREDITY and ENVIRONMENT. ENVIRONMENT: all outside forces that act on an organism. Heredity Chapter 3 3:1 Genetics Mendelian Genetics You are who you are due to the interaction of HEREDITY and ENVIRONMENT. ENVIRONMENT: all outside forces that act on an organism. HEREDITY: traits that

More information

Chapter 17 Genetics Crosses:

Chapter 17 Genetics Crosses: Chapter 17 Genetics Crosses: 2.5 Genetics Objectives 2.5.6 Genetic Inheritance 2.5.10.H Origin of the Science of genetics 2.5.11 H Law of segregation 2.5.12 H Law of independent assortment 2.5.13.H Dihybrid

More information

1/9/2014. Introduction to Genetics. The Work of Gregor Mendel THE WORK OF GREGOR MENDEL. Some Definitions:

1/9/2014. Introduction to Genetics. The Work of Gregor Mendel THE WORK OF GREGOR MENDEL. Some Definitions: Introduction to Genetics Chapter 11 Chapter 11 Section 1 THE WORK OF GREGOR MENDEL The Work of Gregor Mendel Some Definitions: Genetics the study of biological inheritance and variation Chromosomes hereditary

More information

Genetics: CH9 Patterns of Inheritance

Genetics: CH9 Patterns of Inheritance Genetics: CH9 Patterns of Inheritance o o Lecture note Directions Highlight Key information (10-30% of most slides) My Thoughts: Questions, comments, additional information, connections to prior knowledge,

More information

Chapter 11. Introduction to Genetics

Chapter 11. Introduction to Genetics Chapter 11 Introduction to Genetics A Brief History In the past, people did not understand how traits were inherited, but there were many guesses based on things that could be observed. Two theories emerged.

More information

Gregor Mendel Father of Genetics

Gregor Mendel Father of Genetics Genetics and Mendel Gregor Mendel Father of Genetics Gregor Mendel First person to trace characteristics of living things Augustinian Monk Lived and worked in an Austrian monastery in the mid-1800s Parents

More information

Unit 3. Intro. Genetics The branch of biology that deals with variation (differences) and inheritance. Genetics. Sep 6 5:24 PM.

Unit 3. Intro. Genetics The branch of biology that deals with variation (differences) and inheritance. Genetics. Sep 6 5:24 PM. Unit 3.notebook June 03, 2014 Unit 3 Genetics Sep 6 5:24 PM Intro Genetics The branch of biology that deals with variation (differences) and inheritance. Feb 27 1:30 PM Intro Heredity The passing of genetic

More information

Genetics. the of an organism. The traits of that organism can then be passed on to, on

Genetics. the of an organism. The traits of that organism can then be passed on to, on Genetics DNA contains the genetic code for the production of. A gene is a segment of DNA, which consists of enough bases to code for many different proteins. The specific proteins produced by a gene determine

More information

Meiosis and Genetics

Meiosis and Genetics Meiosis and Genetics Humans have chromosomes in each cell What pattern do you notice in the human karyotype (a technique that organizes chromosomes by type and size)? Humans are diploid 1 Gametes are produced

More information

The Experiments of Gregor Mendel

The Experiments of Gregor Mendel 11.1 The Work of Gregor Mendel 11.2 Applying Mendel s Principles The Experiments of Gregor Mendel Every living thing (plant or animal, microbe or human being) has a set of characteristics inherited from

More information

Mendel rigorously followed various traits in the pea plants he bred. He analyzed

Mendel rigorously followed various traits in the pea plants he bred. He analyzed 4.2.a Mendelian Genetics Mendel explained how a dominant allele can mask the presence of a recessive allele. Real-World Reading Link There are many different breeds of dogs, such as Labrador retrievers,

More information

Genetics & Heredity 11/16/2017

Genetics & Heredity 11/16/2017 Genetics & Heredity Biology I Turner College & Career High School 2017 Fertilization is the fusion of an egg and a sperm. Purebred (True breeding plants) are plants that were allowed to selfpollinate and

More information

Class *GENETIC NOTES & WORKSHEETS

Class *GENETIC NOTES & WORKSHEETS Name Class *GENETIC NOTES & WORKSHEETS DAY 1: Mendelian Genetics Vocabulary A. Genetics- Study of B. Heredity- The passing on of characteristics (traits) from to C. Trait A particular that can vary from

More information

Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 6 Patterns of Inheritance

Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 6 Patterns of Inheritance Chapter 6 Patterns of Inheritance Genetics Explains and Predicts Inheritance Patterns Genetics can explain how these poodles look different. Section 10.1 Genetics Explains and Predicts Inheritance Patterns

More information

Honors Biology Review Sheet to Chapter 9 Test

Honors Biology Review Sheet to Chapter 9 Test Honors Biology Review Sheet to Chapter 9 Test Name Per 1. Label the following flower: sepal, petal, anther, filament, style, ovary, stigma Draw in ovules and label. Color the female structure red and the

More information

Name Period. Keystone Vocabulary: genetics fertilization trait hybrid gene allele Principle of dominance segregation gamete probability

Name Period. Keystone Vocabulary: genetics fertilization trait hybrid gene allele Principle of dominance segregation gamete probability Name Period BIO B2 GENETICS (Chapter 11) You should be able to: 1. Describe and/or predict observed patterns of inheritance (dominant, recessive, co- dominant, incomplete dominance, sex- linked, polygenic

More information

Chapter 9. Patterns of Inheritance. Lectures by Chris C. Romero, updated by Edward J. Zalisko

Chapter 9. Patterns of Inheritance. Lectures by Chris C. Romero, updated by Edward J. Zalisko Chapter 9 Patterns of Inheritance Lectures by Chris C. Romero, updated by Edward J. Zalisko 2010 Pearson Education, Inc. PowerPoint Lectures for Campbell Essential Biology, Fourth Edition Eric Simon, Jane

More information

Unit 5: Genetics Guided Notes

Unit 5: Genetics Guided Notes 1 Unit 5: Genetics Guided Notes Basic Mendelian Genetics Before Gregor Mendel 1) When Mendel started his work, most people believed in the blending theory of inheritance. (Inheritance, Heredity, and Genetics

More information

Mendel explained how a dominant allele can mask the presence of a recessive allele.

Mendel explained how a dominant allele can mask the presence of a recessive allele. Section 2: Mendel explained how a dominant allele can mask the presence of a recessive allele. K What I Know W What I Want to Find Out L What I Learned Essential Questions What is the significance of Mendel

More information

Patterns of Inheritance

Patterns of Inheritance Patterns of Inheritance Mendel the monk studied inheritance keys to his success: he picked pea plants he focused on easily categorized traits he used true-breeding populations parents always produced offspring

More information

VOCABULARY somatic cell autosome fertilization gamete sex chromosome diploid homologous chromosome sexual reproduction meiosis

VOCABULARY somatic cell autosome fertilization gamete sex chromosome diploid homologous chromosome sexual reproduction meiosis SECTION 6.1 CHROMOSOMES AND MEIOSIS Study Guide KEY CONCEPT Gametes have half the number of chromosomes that body cells have. VOCABULARY somatic cell autosome fertilization gamete sex chromosome diploid

More information

Class XII Chapter 5 Principles of Inheritance and Variation Biology

Class XII Chapter 5 Principles of Inheritance and Variation Biology Question 1: Mention the advantages of selecting pea plant for experiment by Mendel. Mendel selected pea plants to carry out his study on the inheritance of characters from parents to offspring. He selected

More information

Genetics. by their offspring. The study of the inheritance of traits is called.

Genetics. by their offspring. The study of the inheritance of traits is called. Genetics DNA contains the genetic code for the production of. A gene is a part of DNA, which has enough bases to make for many different proteins. These specific proteins made by a gene decide the of an

More information

Ch 9 Assignment. 2. According to the blending theory of inheritance, a white rabbit crossed with a red rabbit would produce what kind of offspring?

Ch 9 Assignment. 2. According to the blending theory of inheritance, a white rabbit crossed with a red rabbit would produce what kind of offspring? Big idea: Mendel s Laws Answer the following questions as you read modules 9.1 9.10: 1. The study of genetics can be traced back to the Greek physician 2. According to the blending theory of inheritance,

More information

Chapter 11 Introduction to Genetics

Chapter 11 Introduction to Genetics Chapter 11 Introduction to Genetics 11.1 Gregor Mendel Genetics is the scientific study of heredity How traits are passed from one generation to the next Mendel Austrian monk (1822) Used Pea Plants (crossed

More information

Week 4 Day 1 Lab: MENDELIAN TRAITS and INHERITANCE

Week 4 Day 1 Lab: MENDELIAN TRAITS and INHERITANCE Week 4 Day 1 Lab: MENDELIAN TRAITS and INHERITANCE Part 1: Mendelian Traits Alleles are alternative versions of one gene. Alleles are found at the same locus on homologous chromosomes, but may code for

More information

Lecture 13: May 24, 2004

Lecture 13: May 24, 2004 Lecture 13: May 24, 2004 CH14: Mendel and the gene idea *particulate inheritance parents pass on discrete heritable units *gene- unit of inheritance which occupies a specific chromosomal location (locus)

More information

Gregor Mendel father of heredity

Gregor Mendel father of heredity MENDEL AND MEIOSIS Gregor Mendel father of heredity MENDEL S LAWS OF HEREDITY Heredity branch of genetics dealing with the passing on of traits from parents to offspring Pea Plants Easy maintenance & large

More information

Question 2: Which one of the following is the phenotypic monohybrid ratio in F2 generation? (a) 3:1 (b) 1:2:1 (c) 2:2 (d) 1:3 Solution 2: (a) 3 : 1

Question 2: Which one of the following is the phenotypic monohybrid ratio in F2 generation? (a) 3:1 (b) 1:2:1 (c) 2:2 (d) 1:3 Solution 2: (a) 3 : 1 Class X Genetics Biology A. MULTIPLE CHOICE TYPE: (Select the most appropriate option) Which one of the following has the smallest number of chromosomes? (a) Onion (b) Mouse (c) Monkey (d) Ascaris (d)

More information

Introduction to Genetics and Heredity

Introduction to Genetics and Heredity Introduction to Genetics and Heredity Although these dogs have similar characteristics they are each unique! I. Early Ideas About Heredity A. The Theory of Blending Inheritance Each parent contributes

More information

Traits and Probability

Traits and Probability 6.5 Traits and Probability KEY CONCEPT The inheritance of traits follows the rules of probability. S Punnett squares illustrate genetic crosses. A monohybrid cross involves one trait. A dihybrid cross

More information

The Law of Segregation Introduction Today, we know that many of people's characteristics, from hair color to height to risk of diabetes, are

The Law of Segregation Introduction Today, we know that many of people's characteristics, from hair color to height to risk of diabetes, are The Law of Segregation Introduction Today, we know that many of people's characteristics, from hair color to height to risk of diabetes, are influenced by genes. We also know that genes are the way parents

More information

Semester 2- Unit 2: Inheritance

Semester 2- Unit 2: Inheritance Semester 2- Unit 2: Inheritance heredity -characteristics passed from parent to offspring genetics -the scientific study of heredity trait - a specific characteristic of an individual genes -factors passed

More information

Principles of Inheritance and Variation

Principles of Inheritance and Variation Principles of Inheritance and Variation Question 1: Mention the advantages of selecting pea plant for experiment by Mendel. Answer Mendel selected pea plants to carry out his study on the inheritance of

More information

Unit 5: Genetics Notes

Unit 5: Genetics Notes Unit 5: Genetics Notes https://goo.gl/fgtzef Name: Period: Test Date: Table of Contents Title of Page Page Number Date Warm-ups 3-4 Mendelian Genetics Notes 5-6 Mendelian Genetics Lets Practice 7 Monohybrid

More information

You are who you are because of a combination of HEREDITY and ENVIRONMENT. ENVIRONMENT: all outside forces that act on an organism.

You are who you are because of a combination of HEREDITY and ENVIRONMENT. ENVIRONMENT: all outside forces that act on an organism. Unit 6 Genetics 6.1 Genetics You are who you are because of a combination of HEREDITY and ENVIRONMENT. ENVIRONMENT: all outside forces that act on an organism. HEREDITY: traits that are passed from parents

More information

UNIT III (Notes) : Genetics : Mendelian. (MHR Biology p ) Traits are distinguishing characteristics that make a unique individual.

UNIT III (Notes) : Genetics : Mendelian. (MHR Biology p ) Traits are distinguishing characteristics that make a unique individual. 1 UNIT III (Notes) : Genetics : endelian. (HR Biology p. 526-543) Heredity is the transmission of traits from one generation to another. Traits that are passed on are said to be inherited. Genetics is

More information

Biology: Life on Earth

Biology: Life on Earth Teresa Audesirk Gerald Audesirk Bruce E. Byers Biology: Life on Earth Eighth Edition Lecture for Chapter 12 Patterns of Inheritance Copyright 2008 Pearson Prentice Hall, Inc. Chapter 12 Outline 12.1 What

More information

Chapter 9. Patterns of Inheritance. Lectures by Gregory Ahearn. University of North Florida. Copyright 2009 Pearson Education, Inc.

Chapter 9. Patterns of Inheritance. Lectures by Gregory Ahearn. University of North Florida. Copyright 2009 Pearson Education, Inc. Chapter 9 Patterns of Inheritance Lectures by Gregory Ahearn University of North Florida Copyright 2009 Pearson Education, Inc. 9.1 What Is The Physical Basis Of Inheritance? Inheritance occurs when genes

More information

Genetics: Mendel and Beyond

Genetics: Mendel and Beyond Genetics: Mendel and Beyond 10 Genetics: Mendel and Beyond Put the following words in their correct location in the sentences below. crossing over fertilization meiosis zygote 4 haploid prophase I diploid

More information

Mendel. The pea plant was ideal to work with and Mendel s results were so accurate because: 1) Many. Purple versus flowers, yellow versus seeds, etc.

Mendel. The pea plant was ideal to work with and Mendel s results were so accurate because: 1) Many. Purple versus flowers, yellow versus seeds, etc. Mendel A. Mendel: Before Mendel, people believed in the hypothesis. This is analogous to how blue and yellow paints blend to make. Mendel introduced the hypothesis. This deals with discrete units called

More information

Mendelian Genetics. KEY CONCEPT Mendel s research showed that traits are inherited as discrete units.

Mendelian Genetics. KEY CONCEPT Mendel s research showed that traits are inherited as discrete units. KEY CONCEPT Mendel s research showed that traits are inherited as discrete units. Mendel laid the groundwork for genetics. Traits are distinguishing characteristics that are inherited. Genetics is the

More information

UNIT 1-History of life on earth! Big picture biodiversity-major lineages, Prokaryotes, Eukaryotes-Evolution of Meiosis

UNIT 1-History of life on earth! Big picture biodiversity-major lineages, Prokaryotes, Eukaryotes-Evolution of Meiosis Where are we in this course??? UNIT 1-History of life on earth! Big picture biodiversity-major lineages, Prokaryotes, Eukaryotes-Evolution of Meiosis Today we will start with UNIT 2 A. Mendel and the Gene

More information

GENETICS - CLUTCH CH.2 MENDEL'S LAWS OF INHERITANCE.

GENETICS - CLUTCH CH.2 MENDEL'S LAWS OF INHERITANCE. !! www.clutchprep.com CONCEPT: MENDELS EXPERIMENTS AND LAWS Mendel s Experiments Gregor Mendel was an Austrian monk who studied Genetics using pea plants Mendel used pure lines meaning that all offspring

More information

Inheritance. What is inheritance? What are genetics? l The genetic characters transmitted from parent to offspring, taken collectively

Inheritance. What is inheritance? What are genetics? l The genetic characters transmitted from parent to offspring, taken collectively Genetics Interest Grabber Look at your classmates. Note how they vary in the shape of the front hairline, the space between the two upper front teeth, and the way in which the ear lobes are attached. Make

More information

GENETIC VARIATION AND PATTERNS OF INHERITANCE. SOURCES OF GENETIC VARIATION How siblings / families can be so different

GENETIC VARIATION AND PATTERNS OF INHERITANCE. SOURCES OF GENETIC VARIATION How siblings / families can be so different 9/22/205 GENETIC VARIATION AND PATTERNS OF INHERITANCE SOURCES OF GENETIC VARIATION How siblings / families can be so different Independent orientation of chromosomes (metaphase I of meiosis) Random fertilization

More information

Example: Colour in snapdragons

Example: Colour in snapdragons Incomplete Dominance this occurs when the expression of one allele does not completely mask the expression of another. the result is that a heterozygous organism has a phenotype that is a blend of the

More information