READING ASSIGNMENT GENETIC ANALYSIS OF DROSOPHILA POPULATIONS I. HOW DO MITOSIS AND MEIOSIS COMPARE?
|
|
- Anastasia Gallagher
- 6 years ago
- Views:
Transcription
1 READING ASSIGNMENT GENETIC ANALYSIS OF DROSOPHILA POPULATIONS I. HOW DO MITOSIS AND MEIOSIS COMPARE? II. HOW CAN WE DETERMINE EXPECTED RATIOS OF OFFSPRING? What rules can we learn from Mendel s work with pea genetics? III. HOW DO WE KNOW IF OUR OBSERVED RESULTS SUPPORT THE GENETICS PROPOSED? How does the Chi Square Test help? IV. WHAT DO WE KNOW ABOUT THE DROSOPHILA LIFE CYCLE? Reading Assignment - Genetics
2 I. HOW DO MITOSIS AND MEIOSIS COMPARE? Read the sections in your text book that describe the cell cycle and the stages of mitosis and meiosis. After reading these you should know: 1) which cells in your body undergo mitosis and for what reasons do they undergo mitosis. 2) the various stages of mitosis and how they can be recognized. 3) which cells undergo meiosis and for what reasons they undergo meiosis rather than mitosis. 4) the stages of meiosis and how they can be recognized. 5) the major differences between mitosis and meiosis. 6) what relationship(s) Mendel's laws of independent assortment and segregation have to specific meiotic events. A. Based on your reading, complete the following table. C Fill in the major events which occur in each phase of mitosis, meiosis I and meiosis II. C In the last row of the table indicate which events of a given stage are common (that is which occur in all three of the division cycles: mitosis, meiosis I and meiosis II) and which are different or unique (occur in only one of the division cycles). Then answer the following questions. Mitosis Interphase Prophase Metaphase Anaphase Telophase Cytokinesis Meiosis I Meiosis II Common events vs. differences B. Answer the following summary questions. 1. How does mitosis differ from meiosis? 2. What are the major differences between meiosis I and meiosis II? 3. Why is it essential that the resulting cell products of meiosis (which will become gametes) have half the number of chromosomes of the parental cells? Reading Assignment - Genetics
3 II. HOW CAN WE DETERMINE EXPECTED RATIOS OF OFFSPRING? What rules can we learn from Mendel s work with pea genetics? A. Who was Mendel? Genetics, as a field of scientific inquiry, began with the studies of Gregor Mendel, an Austrian monk. In 1865, he reported the results of eight years of breeding experiments with plants to the Naturalist Society of Brun. Mendel's experiments, and those of many scientists since, demonstrated that many characteristics of individuals are inherited as individual units, now referred to as genes. Mendel's analysis is especially impressive since the importance of chromosomes and the mechanics of mitosis and meiosis had yet to be discovered. B. What kinds of research did Mendel do? Mendel discovered the genetics of specific traits by doing controlled crosses of known parents. He began by establishing pure breeding lines of plants which displayed contrasting genetic characteristics such as tall vs. short plants, yellow vs. green seeds, smooth vs. wrinkled seeds. A pure breeding line of tall plants mated with each other will always produce tall offspring. Similarly, a pure breeding line of plants with red flowers when crossed with each other always produce offspring with red flowers. Today we would say that these lines are homozygous for the gene in question. In one set of experiments, Mendel crossed a pure tall line to a pure short line and made the following observations. 1. Parental generation (P) -- Tall plants crossed with short plants 2. First filial generation (F 1 ) -- All offspring are tall 3. Tall F 1 offspring crossed with each other 4. Second filial generation (F 2 ) tall plants and 277 short plants Similar results were obtained for all seven pairs of characteristics Mendel studied. He concluded that: a) Inherited characteristics were controlled by pairs of factors (alleles of genes). b) Each individual contains a pair of such factors (alleles) for a particular gene. c) During the formation of gametes, this pair is separated or segregated, so that only one member of the pair appears in any one gamete. d) At fertilization, the single allele in the sperm and the single allele in the egg are combined so that the new individual again has a pair of alleles for that trait. In the example above, each of the tall plants contained a pair of alleles for tall stature and the short plants contained a pair of alleles for short stature. When the mating occurred, each parent (the P generation) contributed a single allele of the gene for height to the offspring. The tall plant, TT, contributed one T allele. The short plant (tt) contributed one t allele. The F 1 plants therefore had the genotype, Tt. These plants appeared tall because, in this case, the tall allele (T) was dominant over the short allele (which is then said to be recessive). When two F 1 plants are crossed, Tt crossed to Tt, each parent will contribute a T allele half of the Reading Assignment - Genetics
4 time and a t allele the other half of the time. This will result in three different genotypes, but two different phenotypes as shown in the offspring below: (½) T Sperm (½) t Eggs (½) T TT (1/4) Tt (1/4) (½) t Tt (1/4) tt (1/4) This results in 1/4 TT, (1/4 + 1/4) Tt, and 1/4 tt. Since TT and Tt individuals are phenotypically indistinguishable (all look alike; all are tall), the tall offspring would make up 3/4 of the total and the short, 1/4. This was just what Mendel observed. This is an illustration of what is now known as Mendel s law of segregation. Here, it is the individual alleles of a gene which are segregated. We know now that this occurs during anaphase I of meiosis when homologous chromosomes migrate to opposite poles of the spindle. As a result, the two alleles of each gene are physically separated or compartmentalized into gametes. C. Dihybrid Crosses Go one step further, as Mendel did, and deal with two specific traits, size and color, e.g. tall vs. short and yellow vs. green. Here, tall is dominant to short and yellow is dominant to green. In this dihybrid cross the parental genotypes would be TTYY and ttyy. The F1 genotypes would all be TtYy. We can predict the number of different genotypes that should appear in the F2 by using a Punnet square. To do this we must first determine how many different kinds of sex cells (gametes) an individual with the genotype, TtYy, can produce. The answer is four, because each gamete must have one allele from each pair but it makes no difference which one. The number of possible gametes can be calculated from the formula: 2 n = number of possible gametes. Here n = the number of heterozygous allele pairs (genes on separate chromosome pairs) under consideration. The four possible gamete combinations for this example would be: T t Y TY ty y Ty ty Next we use a Punnet square to determine expected types and probabilities of offspring for the cross. A Punnet square lists male gametes on one side and female gametes on the other. This allows you to visualize all possible combinations of male and female gametes. Therefore, the hypothetical or expected proportions of various genotypes and phenotypes can be determined. SAMPLE PUNNET SQUARE : Reading Assignment - Genetics
5 Sperm TY Ty ty ty TY Eggs Ty ty ty 1. Use this Punnet square to combine the gametes in all possible ways. 2. What expected phenotypic and genotypic ratios result in the offspring? 3. How were you able to determine this? This illustrates Mendel's Law of Independent Assortment. This law states that the alleles of different pairs of genes will assort (segregate) independently of each other during gamete formation. (Note: This is true, only if the genes in question are on different pairs of homologous chromosomes, i.e. are not linked on the same chromosome. In addition, genes that are very far apart on the same chromosome have a high probability of cross over. As a result, they may appear to be unlinked and to segregate independently.) If the genes in question assort independently, we can also solve problems like this by solving for each gene separately. For example, we can treat the cross of TtYy X TtYy as two separate crosses: Tt X Tt and Yy X Yy. We know that these crosses will produce: Tt X Tt 3/4 tall 1/4 short Yy X Yy 3/4 yellow 1/4 green In combination, these would yield: 3/4 tall 1/4 short 3/4 yellow 1/4 green 3/4 x 3/4 = 9/16 tall, yellow 3/4 x 1/4 = 3/16 tall, green 1/4 x 3/4 = 3/16 short, yellow 1/4 x 1/4 = 1/16 short, green Keep in mind that every offspring has to have both size and color and that the most frequent size and most frequent color will be observed together most often. Reading Assignment - Genetics
6 Terms to Know: Phenotype - the expression of the genes in an individual organism; what the individual looks like, e.g. tall, green, blonde. Genotype - the combination of genes found in an individual organism, e.g. TT, Tt, tt. If T (tall) is dominant, both TT and Tt individuals will be tall (have the same phenotype), but their genotypes will differ. Allele - different or contrasting forms of the same gene. For example, T (tall) and t (short) are alleles of the gene for overall height of the organism. Homozygous - an individual is said to be homozygous for a given gene when the two alleles in the genotype are the same. For example, TT is homozygous tall and tt is homozygous short. Heterozygous - an individual is said to be heterozygous for a given gene when the two alleles in the genotype are different, e.g. Tt. If T (tall) is dominant, this individual would display the tall phenotype. Hemizygous - the special condition seen when an otherwise diploid organism has only one representation (allele) of certain genes. For example, in mammals, females are XX (have two X chromosomes) and males are XY (have an X and a Y chromosome). For most genes on the X chromosome, there is no allele on the Y. For these genes, males would be hemizygous, i.e. have only one allele of these genes. III. HOW DO WE KNOW IF OUR OBSERVED RESULTS SUPPORT THE GENETICS PROPOSED? How does the Chi Square Test help? Expected ratios from a given genetic cross can be calculated. For example, if two genes are assorting independently, the offspring of individuals heterozygous for both genes are expected to occur in a 9:3:3:1 phenotypic ratio. However, observed ratios of offspring often differ from expected ratios. This occurs because each cross, like each flip of a coin, is subject to errors of sampling, or chance deviation from ideal or expected values. If you think about it, the significance of a given deviation is clearly related to sample size. If chance alone is causing the observed deviation from expected, larger samples should result in less deviation than smaller samples. For example, you are more likely to come closer to 500 heads and 500 tails out of 1000 flips of a coin than you are to 5 heads and 5 tails out of 10 flips of the same coin. On the other hand, if the deviation is consistently large, it is likely that something other than chance alone is operating. For example, if you flipped a coin 100 times and turned up 90 heads (a deviation of 40 from the expected 50), you would suspect a biased coin. Reading Assignment - Genetics
7 Chance variation can also affect the outcome of genetics experiments. In a cross of Tt (heterozygous tall) by tt (homozygous recessive short) you would expect a 1:1 ratio of tall to short in the offspring. In Experiment 1, you evaluate only 40 offspring, and find 30 tall and 10 short, the deviation of 10 may seem significant. Experiment 1: Tall Short Observed: Expected: Deviation: In Experiment 2, when you evaluate 200 offspring from the same cross, a deviation of 10 may seem less significant. Experiment 2: Tall Short Observed: Expected: Deviation: Using the Chi Square statistical test allows you to determine if the deviation you observe is significantly different from that expected on the basis of chance deviation alone. The Chi Square test is calculated as follows. 1. Observed values (number of actual offspring from a cross) are counted and expected values are calculated based on the assumed genetics. If you assume you are crossing a heterozygote with a homozygous recessive you would expect ½ the offspring to be dominant and ½ to be recessive for phenotype. To calculate the expected values multiply the total number of offspring actually counted by ½ to get each expected value. 2. Subtract the observed number of offspring from the expected number then square the resulting difference or deviation. Experiment 1 (30-20) 2 + (10-20) 2 = (10) 2 + (-10) 2 = 200 Experiment 2 (90-100) ) 2 = (-10) 2 + (10) 2 = Divide each squared deviation by the number you expected for that class. (In the example above, there are two classes, tall and short.) Experiment 1 100/ /20 = 10 Experiment 2 100/ /200 = 1 4. The resulting quotients (values from 3) are added together to yield the Chi Square value (O 2 ) for the distribution. O 2 = 3(d 2 /e) Here 3 means the sum of ; d = deviation = (observed - expected) and e = expected. In the examples above, two traits (classes) were possible. Where four offspring classes are possible, it becomes reasonable to allow the value of O 2 to be larger before questioning the hypothesis that chance alone explains the deviation. Conventionally, the effect of the number of independent classes is recognized as degrees of freedom. The number of degrees of freedom in tests of genetic ratios is almost always one less than the number of classes possible. Thus, in tests of 1:1 or 3:1 ratios, there would be one degree of freedom (two possible classes of offspring minus one = 1 degree of freedom). A test of a 1:2:1 ratio would have two Reading Assignment - Genetics
8 degrees of freedom and so on. To help you understand why degrees of freedom are calculated as they are, consider the situation encountered when you put your shoes on. You have two shoes, but only one degree of freedom. This occurs because you have one decision to make, that is, which shoe to put on the first foot. Once that decision is made, right or wrong, the other shoe has to go on the remaining foot; there is no other option. The first decision (or value) can be thought of as arbitrary; the last, as fixed by assigning a value (foot) to the first. After calculating O 2 and determining degrees of freedom, you can determine the probability that your deviation from expected is due to chance alone by consulting a O 2 Table. To use the table, look down the column of degrees of freedom to locate the calculated degrees of freedom for your problem. The values in the row next to your value for degrees of freedom are the O 2 values which have been calculated for that number of degrees of freedom. At the top of the table you will see column headings which indicate the probability that a given O 2 value could result from chance deviation alone. To show you how to use the table, assume you have calculated that O 2 equals 2.56 for a problem where there are two degrees of freedom. 1. Go to the degrees of freedom column and read down it until you find 2". 2. Read across the row for 2 degrees of freedom to determine where your calculated O 2 value of 2.56 would fall. In this example, 2.56 falls between and Read up the columns which contain the numbers and These correspond to p values of 0.5 and 0.2 respectively. 4. This indicates that between 20 and 50% of the time, the deviation you observed in your data could be accounted for by chance alone. Such a deviation is not significant enough to indicate anything other than chance is operating to cause the deviation. In most scientific investigations, p values must be less than 0.05 to be considered significant and less than 0.01 to be considered highly significant. What are the p values for Experiment 1 and Experiment 2 above? How many degrees of freedom are there in each of these experiments? Reading Assignment - Genetics
9 O 2 TABLE Degrees of Freedom p = X 2 ANALYSIS - SAMPLE FORM CLASS OR PHENOTYPE OBS EXP O-E (O-E) 2 (O-E) 2 /E Total: X 2 = Degrees of Freedom = p= Reading Assignment - Genetics
10 IV. WHAT DO WE KNOW ABOUT THE DROSOPHILA LIFE CYCLE? Much of our knowledge of genetics has been gathered from extensive studies of the fruit fly, Drosophila melanogaster. The life cycle of the fruit fly is completed in 10 days at 25 C, the optimal temperature. There are four stages in the life cycle: egg, larva, pupa and adult (see figure below). The duration of each of these stages depends on many environmental factors, especially temperature. The life cycle is completed more quickly at higher temperatures and more slowly at lower temperatures. During the larval stage, there are two molts and three larval periods or instars. Pupation usually occurs on a dry surface. Upon emerging, the adults appear lightly colored with folded wings. Within a short time, they darken, their exoskeletons harden and their wings expand. Males can be distinguished from females because males are usually shorter with the posterior region of the abdomen more blunt. Females have a more pointed abdomen. On the female s dorsal abdominal surface, there are alternating dark and light color bands which extend to the tip of the abdomen. In the male the posterior third of the abdomen is a solid dark color. Female fruit flies can store sperm for relatively long periods of time. Therefore, it is important that females used in genetics experiments be virgins to control for the source of the sperm and/or paternal genotype. Newly emerged males will not mate for 12 hours. This allows us to collect virgin females for mating experiments by removing all flies from breeding vials at time t = 0. Eight hours later, the flies which have hatched are collected and separated by sex. Using this technique, these hatchlings will all be virgins. Reading Assignment - Genetics
11 Drosophila life cycle Reading Assignment - Genetics
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 informationGenetics & 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 informationSexual Reproduction and Genetics. Section 1. Meiosis
Chromosomes and Chromosome Number! Human body cells have 46 chromosomes! Each parent contributes 23 chromosomes! Homologous chromosomes one of two paired chromosomes, one from each parent Chromosomes and
More informationYou 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 informationGenetics & 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 informationChapter 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 informationThe 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 informationLesson Overview 11.2 Applying Mendel s Principles
THINK ABOUT IT Nothing in life is certain. Lesson Overview 11.2 Applying Mendel s Principles If a parent carries two different alleles for a certain gene, we can t be sure which of those alleles will be
More informationChapter 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 informationMendelian 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 informationGregor 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 informationMendel 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 informationGenetics & 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 informationExtra 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 informationGenetics & 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 informationObjectives. ! 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 informationChapter 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 informationUNIT 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 informationAgro/ANSC/Biol/Gene/Hort 305 Fall, 2017 MENDELIAN INHERITANCE Chapter 2, Genetics by Brooker (Lecture outline) #2
Agro/ANSC/Biol/Gene/Hort 305 Fall, 2017 MENDELIAN INHERITANCE Chapter 2, Genetics by Brooker (Lecture outline) #2 MENDEL S LAWS OF INHERITANCE Gregor Johann Mendel (1822-1884) is considered the father
More informationMendel 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 informationMendel 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 informationGENETICS 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 information1/9/2014. 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 informationLab 5: Testing Hypotheses about Patterns of Inheritance
Lab 5: Testing Hypotheses about Patterns of Inheritance How do we talk about genetic information? Each cell in living organisms contains DNA. DNA is made of nucleotide subunits arranged in very long strands.
More informationInheritance. 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 informationGENETICS - 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 informationUnit 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 informationGregor 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 informationUNIT 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 informationMendelian 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 informationChapter 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 information8.1 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 informationbiology Slide 1 of 32 End Show Copyright Pearson Prentice Hall
biology 1 of 32 11-1 The Work of Gregor Mendel 2 of 32 Gregor Mendel s Peas Genetics is the scientific study of heredity. Gregor Mendel was an Austrian monk. His work was important to the understanding
More informationMendelian 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 informationLaws 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 informationIntroduction 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 informationMitosis and Meiosis. See Mitosis and Meiosis on the class web page
Mitosis and Meiosis Mitosis and Cellular Reproduction. A cell s hereditary material (DNA) is located on chromosomes in the cell s nucleus. In the process called mitosis, a cell s hereditary material is
More information11-1: Introduction to Genetics
11-1: Introduction to Genetics The Work of Gregor Mendel Copyright Pearson Prentice Hall Genetics Vocabulary Genetics The study of heredity. Heredity The passing of physical characteristics from parents
More informationdraw and interpret pedigree charts from data on human single allele and multiple allele inheritance patterns; e.g., hemophilia, blood types
Specific Outcomes for Knowledge Students will: 30 C2.1k describe the evidence for dominance, segregation and the independent assortment of genes on different chromosomes, as investigated by Mendel 30 C2.2k
More informationSemester 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 informationHEREDITY. Heredity: Tendency of the offsprings to resemble their parents is called Heredity
HEREDITY Heredity: Tendency of the offsprings to resemble their parents is called Heredity Variation: Tendency of the offsprings to differ from their parents is called Variation. Genetics: The branch of
More informationName Hour. Section 11-1 The Work of Gregor Mendel (pages )
Name Hour Section 11-1 The Work of Gregor Mendel (pages 263-266) Introduction (page 263) 1. The scientific study of heredity is called. Gregor Mendel's Peas (pages 263-264) 2. Circle the letter of each
More informationPatterns 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 informationMendelian Genetics. Gregor Mendel. Father of modern genetics
Mendelian Genetics Gregor Mendel Father of modern genetics Objectives I can compare and contrast mitosis & meiosis. I can properly use the genetic vocabulary presented. I can differentiate and gather data
More informationFor 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 informationThe Work of Gregor Mendel
The Work of Gregor Mendel Transmission of characteristics from is parents to offspring called. heredity The SCIENCE that studies how those characteristics are passed on from one generation to the next
More informationGenetics. 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 informationMENDELIAN 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 informationThe Modern Genetics View
Inheritance Mendelian Genetics The Modern Genetics View Alleles are versions of a gene Gene for flower color Alleles for purple or white flowers Two alleles per trait 2 chromosomes, each with 1 gene The
More informationNotes: Mendelian Genetics
Notes: Mendelian Genetics Heredity is passing characteristics from one generation to the next. Genetics is the study of heredity. Who was Gregor Mendel? Gregor Mendel is the Father of Modern Genetics.
More information11.1 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 informationWho was Gregor Mendel and what did he do?
Page 1 of 20 Genetics: Heredity: Trait: The scientific Study of Heredity. The passing of traits from one generation to the next. Any observable characteristic on organism may have. Ex: eye colour, hair
More informationThe 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 informationSummary The Work of Gregor Mendel Probability and Punnett Squares. Oass
--------------------------- Oass ---------------- Date Chapter 11 Summary Introduction to Genetics 11-1 The Work of Gregor Mendel The scientific study of heredity is called genetics. Gregor Mendel used
More informationBiology 12. Mendelian Genetics
Mendelian Genetics Genetics: the science (study) of heredity that involves the structure and function of genes and the way genes are passed from one generation to the next. Heredity: the passing on of
More informationChapter 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 informationbiology Slide 1 of 32
biology 1 of 32 11-1 The Work of Gregor 11-1 The Work of Gregor Mendel Mendel 2 of 32 Gregor Mendel s Peas Gregor Mendel s Peas Genetics is the scientific study of heredity. Gregor Mendel was an Austrian
More informationGregor Mendel. Father of Genetics
Gregor Mendel Father of Genetics Genetics Branch of biology which deals with principles of variations in traits (distinguishing characteristics) and inheritance Allows us to predict patterns of inheritance
More informationThe Work of Gregor Mendel. Guided Reading
The Work of Gregor Mendel Guided Reading Gregor Mendel 25 min Mendel (pearson) 6 min The Experiments of Gregor Mendel 1. What is Heredity? The delivery of characteristics from parents to offspring 2. What
More informationVOCABULARY. 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 informationSection 1 MENDEL S LEGACY
Chapter 9 Genetics Section 1 MENDEL S LEGACY Genetics is the field of biology devoted to understanding how characteristics are transmitted from parents to offspring Genetics was founded with the work of
More informationPatterns of Inheritance. { Unit 3
Patterns of Inheritance { Unit 3 Austrian monk, gardener, scientist First acknowledged to study heredity the passing on of characteristics from parents to offspring Traits characteristics that are inherited
More informationGenetics 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 informationPatterns 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 informationTest Booklet. Subject: SC, Grade: HS Genetics Assessment. Student name:
Test Booklet Subject: SC, Grade: HS Genetics Assessment Student name: Author: Megan Kitchens School: SHAW HIGH SCHOOL Printed: Monday January 30, 2017 1 In fruit flies, the gray body color (G) is dominant
More informationHonors Biology Test Chapter 9 - Genetics
Honors Biology Test Chapter 9 - Genetics 1. The exceptions to the rule that every chromosome is part of a homologous pair are the a. sex chromosomes. c. linked chromosomes. b. autosomes. d. linked autosomes.
More informationGregor 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 informationGenetics. 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 informationWriting the Rules of Heredity. 23. Genetics I
1. 2. 3. 4. 5. 6. 7. Describe the general aspects of Mendel s experimental method, and explain why his work is considered so important. Define the following terms: gene, F 1 generation, F 2 generation,
More informationBiology 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 informationHEREDITY. 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 information5.5 Genes and patterns of inheritance
5.5 Genes and patterns of inheritance Mendel s laws of Inheritance: 1 st Law = The law of segregation of factors states that when any individual produces gametes, the alleles separate, so that each gamete
More informationTraits 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 informationIntroduction to Genetics
DAY 2 Introduction to Genetics Heredity Passing of traits from parents to their young The branch of biology that studies heredity is genetics. Trait Characteristic that is inherited Gregor Mendel Austrian
More informationGenetics 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 informationSection 11 1 The Work of Gregor Mendel (pages )
Chapter 11 Introduction to Genetics Section 11 1 The Work of Gregor Mendel (pages 263 266) This section describes how Gregor Mendel studied the inheritance of traits in garden peas and what his conclusions
More informationWhat we mean more precisely is that this gene controls the difference in seed form between the round and wrinkled strains that Mendel worked with
9/23/05 Mendel Revisited In typical genetical parlance the hereditary factor that determines the round/wrinkled seed difference as referred to as the gene for round or wrinkled seeds What we mean more
More informationGenetics: field of biology that studies heredity, or the passing of traits from parents to offspring Trait: an inherited characteristic, such as eye
Genetics: field of biology that studies heredity, or the passing of traits from parents to offspring Trait: an inherited characteristic, such as eye colour or hair colour Gregor Mendel discovered how traits
More informationQuestion 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 informationExperiment 1. The aim here is to understand the pattern of
H A Ranganath and M T Tanuja Drosophila Stock Centre Department of Studies in Zoology University of Mysore Manasagangotri Mysore 570006, India. E-mail:drosrang@bgl.vsnl.net.in hranganath@hotmail.com Part
More informationCh 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 informationMENDELIAN GENETICS. Law of Dominance: Law of Segregation: GAMETE FORMATION Parents and Possible Gametes: Gregory Mendel:
MENDELIAN GENETICS Gregory Mendel: Heredity: Cross: X P1 Generation: F1 Generation: F2 Generation: Gametes: Dominant: Recessive: Genotype: Phenotype: Law of Dominance: Genes: Alleles: Law of Segregation:
More informationA gene is a sequence of DNA that resides at a particular site on a chromosome the locus (plural loci). Genetic linkage of genes on a single
8.3 A gene is a sequence of DNA that resides at a particular site on a chromosome the locus (plural loci). Genetic linkage of genes on a single chromosome can alter their pattern of inheritance from those
More informationPROBABILITY and MENDELIAN GENETICS
PROBABILITY and MENDELIAN GENETICS NAME BACKGROUND In 1866 Gregor Mendel, an Austrian monk, published the results of his study of inheritance on garden peas. Although Mendel did not understand the mechanics
More informationChapter 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 informationSemester 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 informationGenetics 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 informationLinkage Mapping in Drosophila Melanogaster
Linkage Mapping in Drosophila Melanogaster Genetics: Fall 2012 Joshua Hanau Introduction: An experiment was performed in order to determine the presence and degree of gene linkage in Drosophila Melanogaster.
More informationIB BIO I Genetics Test Madden
Name Date Multiple Choice 1. What does the genotype X H X h indicate? A. A co-dominant female B. A heterozygous male C. A heterozygous female D. A co-dominant male 2. A pure breeding tall plant with smooth
More informationHEREDITY = The passing of traits from parents to offspring. Transmitted by means of information stored in molecules of DNA.
HEREDITY = The passing of traits from parents to offspring. Transmitted by means of information stored in molecules of DNA. GENEITCS =Scientific study of heredity Based on knowledge that traits are transmitted
More informationPunnett Squares. Dihybrid Cross
Punnett Squares Dihybrid Cross 6F: Students will predict possible outcomes of genetic combinations such as monohybrid crosses, dihybrid crosses, and non-mendelian inheritance TEKS Each parent has TWO traits
More informationChapter 02 Mendelian Inheritance
Chapter 02 Mendelian Inheritance Multiple Choice Questions 1. The theory of pangenesis was first proposed by. A. Aristotle B. Galen C. Mendel D. Hippocrates E. None of these Learning Objective: Understand
More informationMendel 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 informationWhen Mendel crossed 2 plants that were different in a single trait, he called that a monohybrid cross. The resulting offspring were called the F1
Genetics Gregor Mendel The father of Genetics Genetics- the study of heredity Heredity- the passing of characteristics or traits from parents to offspring Mendel chose pea plants to research. Pea plants
More informationUnit 11 Test: Genetics Date: /Period:
Name: 1. Compared to human cells resulting from mitotic cell division, human cells resulting from meiotic cell division would have A) twice as many chromosomes B) the same number of chromosomes C) one-half
More informationVOCABULARY 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 informationMendelian Genetics. Activity. Part I: Introduction. Instructions
Activity Part I: Introduction Some of your traits are inherited and cannot be changed, while others can be influenced by the environment around you. There has been ongoing research in the causes of cancer.
More informationThe Chromosomal Basis of Inheritance
The Chromosomal Basis of Inheritance Factors and Genes Mendel s model of inheritance was based on the idea of factors that were independently assorted and segregated into gametes We now know that these
More information12 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