SEX DETERMINATION AND SEX CHROMOSOMES
|
|
- Maximilian Bailey
- 5 years ago
- Views:
Transcription
1 Klug et al. 2006, 2009 Concepts of Genetics Chapter 7 STUDY UNIT 5 SEX DETERMINATION AND SEX CHROMOSOMES Some species reproduce asexually Most diploid eukaryotes reproduce sexually Parent (2n) Parent (2n) meiosis segregation & independent assortment genetic variation Gamete (n) Gamete (n) fertilisation Offspring (2n) Sexual differentiation and life cycles Chlamydomonas: sexual differentiation: development of gonads where gametes are produces Secondary sexual differentiation: overall appearance of organism Unisexual / dioecious / gonochoric: An individual containing only male or female reproductive organs: Bisexual / monoecious / hermaphrodite: An individual containing both male and female organs: Intersex: Individuals of intermediate sexual differentiation: Isogametes = morphologically indistinguishable, but of two different mating types Fig 7-1 & 7-2 Fig 2-12 Zea mays (fig 7-3): Monoecious seed plant, sporophyte phase predominant Caenorhabditis elegans 2 sexual phenotypes Male only testes Hermaphrodite testes and ovaries : Stamen (tassel) microspore mother cell (2n) meiosis microspores mitosis microgametophyte (pollen grain) : Pistil megaspore mother cell (2n) meiosis megaspores mitosis megagametophyte (embryo sac) Double fertilisation occurs Sexual differentiation determined by Larval development of hermaphrodites: Testes form produce sperm stored Ovaries form oogenesis occurs in adult stage Eggs fertilized by stored sperm Fig 7-4 1
2 Male vs hermaphrodite Triggered by genes on X chromosomes and autosomes Sex chromosomes and sex determination XX / XO or Protenor mode: Hermaphrodites: Males: Believed that the ratio of X chromosomes to number of sets of autosomes determines sexual phenotype. X / A = 1 = hermaphrodite Certain insect species, eg grasshoppers Contain only one type of sex chromosome = X chromosome Females: XX all gametes X Males: X ½ gametes X : ½ gametes Fig 7-5a X / A = 0.5 = male XX / XY or Lygaeus mode: Some insects, all mammals, some other species Contain two types of sex chromosome = X chromosome & Y chromosome (usually smaller) Females: XX all gametes X Males: XY ½ gametes X : ½ gametes Y Fig 7-5b sex that produces different gametes with respect to chromosome numbers and types male in XX / XO system male in XX / XY system sex that produces uniform gametes with respect to chromosome numbers and types female in XX / XO system female in XX / XY system QUESTIONS: ZZ / ZW mode: Similar to XX / XY mode, only female is heterogametic and male homogametic sex. Most birds, some moths, butterflies, fish. Contain two types of sex chromosome = Z chromosome & W chromosome (usually smaller) ZW ½ gametes Z : ½ gametes W ZZ all gametes Z 1. An insect species is discovered in which the heterogametic sex is unknown. An X-linked recessive mutation for reduced wing (rw) is discovered. Contrast the F 1 and F 2 from a cross between a female with reduced wings and a male with normal sized wings when: a. the female is the heterogametic sex b. the male is the heterogametic sex 2
3 2. Based on your answer in Q1, is it possible to distinguish between the Protenor and Lygaeus mode of sex determination based on the outcome of the crosses? 3. In the wasp Bracon hebetor, a form of parthenogenesis (where unfertilized eggs initiate development) resulting in haploid organisms is not uncommon. All haploids are male. When offspring arise from fertilization, females almost invariably result. It has been shown that an X-linked gene with nine multiple alleles (X a, X b, etc) controls sex determination. Any homozygous or hemizygous condition results in males and any heterozygous condition results in females. If an X a X b female mates with an X a male and lays 50% fertilized and 50% unfertilized eggs, what proportion of male and female offspring will result? Sex determination in humans XX / XY system : : Fig 7-6 Turner syndrome 1/2000 female births. Normal intelligence. Female external genitalia. Fig 7-7b Rudimentary ovaries. Short stature. Results from: Gamete where nondisjunction of X occurred during meiosis. Somatic mosaics due to mitotic error in early embryo. (45,X / 46,XY or 45,X / 46,XX) Does Y chromosome determine maleness? (Stine, 1989) Klinefelter syndrome 2/1000 male births. Below normal intelligence. Fig 7-7a Male external genitalia. Rudimentary testes. Tall. Results from: Gamete where nondisjunction of X occurred during meiosis. Other karyotypes: 48,XXXY, 48,XXYY, 49,XXXY, 49,XXXYY. From Turner & Klinefelter syndromes: Y-chromosome determines maleness. 47,XXX Syndrome 48,XXXX 49,XXXXX 1/1200 female births. Variable expression. Delicate balance of gene expression disrupted. 47,XYY Condition Additional Y chromosome Table 7-1 (Stine, 1989) 3
4 Human sexual differentiation Embryo week 5 gonadal ridges on kidney 2 sets of undifferentiated tubes Week 7: XY Ridges Testes Fig 7-8 Human Y chromosome Fig 7-9 Absence of Y Ridges Ovaries MSY region of Y chromosome: 23 Mb X-transposed region 15% of MSY, 99% homology to Xq21 X-degenerative region 20% of MSY, some homology to X chromosome Includes SRY gene SRY encodes TDF determines male development Evidence: Humans Mice Ampliconic region 30% of MSY, no X chromosome homology testes development, male fertility Sex ratio: Proportion of male to female offspring. Expect ratio of 1.0 with XX / XY sex chromosome system. Dosage compensation prevents excessive expression of X-linked genes Barr body / sex chromatin In humans: Primary 1.06 Secondary proportion at conception. proportion at birth. Fig 7-10 Dark staining body in interphase nucleus of female somatic cells = Number of Barr bodies = number of X chromosomes - 1 Fig 7-11 Lyon hypothesis X chromosome inactivation is random, inactivation of one X occurs randomly in each somatic cell early in embryonic development. After inactivation all progeny cells have the same X chromosome inactivated. Explains: phenotypic mosaics in females heterozygous for X-linked genes, eg tortoiseshell cats. Fig 7-12 Examples in humans: Red-green colour blindness Anhidrotic ectodermal dysplasia. Mechanism of inactivation: X-inactivation center ( ). Fig 7-13 Expressed only in inactivated X chromosome. X-inactive specific transcript ( ) = large RNA transcript without an open reading frame, RNA product coats X chromosome and leads to inactivation. 4
5 Sex determination in Drosophila (fig 7-15) : 2n = 8 2 sets of autosomes (2A) + XX : 2n = 8 2 sets of autosomes (2A) + XY Y chromosome plays no role in sex determination, only in male fertility. Sex is determined by the ratio of X chromosomes to the number of haploid sets of autosomes (A). (Model formulated after study of abnormal meioses.) Genic balance theory: Interaction between autosomal genes and genes on X chromosome determine sex. 1X : 2A threshold for maleness 2X : 2A alters balance, female differentiation. Dosage compensation in Drosophila: No X chromosome inactivation in females. Male X-linked genes transcribed at twice the level of the same genes in females. Mechanism of dosage compensation in Drosophila Master switch Sxl gene At least 4 autosomal genes involved Master switch gene Sxl induces female differentiation during sex determination MODEL Mle (maleless) autosomal gene protein binds X chr enhances genetic expression. Products of 3 other autosomal genes required for mle binding. Male-specific lethals (MSLs) proteins bind to gene-rich regions of chr X increase gene expression in male flies. Cluster of gene-activating proteins Dosage Compensation Complex (DCC). Fig Sxl activated Autosomal genes activated Enhanced X chromosome activity Sxl active Inactivates 1 / more Autosomal genes mle? No doubling of expression of X-linked genes Drosophila mosaics: Recovered from stock where all females were heterozygous for X-linked genes white eye (w) and miniature wing (m) Bilateral gynandromorph Temperature variation controls sex determination in reptiles Temperature-dependent sex determination as opposed to chromosomal or genotypic sex determination in previous examples. Male half, white eyes, miniature wings Fig 7-17 Female half, normal red eyes, normal large wings Fig 7-18 X w,m O X w+,m+ X w,m XX zygote lost one X chromosome during 1 st mitotic division All crocodiles, most turtles, some lizards 5
6 In all three patterns: Certain temperatures produce males and females. Pivotal temperature (T p ) is fairly narrow. How? Androgens Estrogens (male hormones) Aromatase (female hormones) enzyme 4. Shown below are two graphs that plot the percentage of males occurring against the atmospheric temperature during early development of fertilized eggs in a) snapping turtles and b) most lizards. Interpret these data as they relate to the effect of temperature on sex determination. Thermosensitive factor controls transcription 5. In chickens, the gene for black feathers (B) is dominant over the gene for brown feathers (b) and is carried on the Z chromosome. A black hen is crossed with a heterozygous black rooster. Give the genotypic and phenotypic ratios of the F 1 progeny. 6
Concepts of Genetics Ninth Edition Klug, Cummings, Spencer, Palladino
PowerPoint Lecture Presentation for Concepts of Genetics Ninth Edition Klug, Cummings, Spencer, Palladino Copyright Copyright 2009 Pearson 2009 Pearson Education, Education, Inc. Inc. Chapter 7 Sex Determination
More informationTerms. Primary vs. secondary sexual differentiation. Development of gonads vs. physical appearances
SEX DETERMINATION How is the sex of an organism determined? Is this process the same for all organisms? What is the benefit of sexual reproduction anyway? Terms Primary vs. secondary sexual differentiation
More informationSexual Reproduction. For most diploid eukaryotes, sexual reproduction is the only mechanism resulting in new members of a species.
Sex Determination Sexual Reproduction For most diploid eukaryotes, sexual reproduction is the only mechanism resulting in new members of a species. Meiosis in the sexual organs of parents produces haploid
More informationLecture 5 Chapter 4: Sex Determination and Sex-Linked Characteristics
Lecture 5 Chapter 4: Sex Determination and Sex-Linked Characteristics Sex determination may be controlled: chromosomally genetically (allelic) environmentally Chromosomal determination Haplodiploidy (bees,
More informationGenetics Lecture 9 Sex Determination. reproductive modes 2/20/2012
Genetics Lecture 9 Sex Determination reproductive modes In the biological world, a wide range of reproductive modes and life cycles are observed. Some organisms are entirely asexual, displaying no evidence
More information1042SCG Genetics & Evolutionary Biology Semester Summary
1042SCG Genetics & Evolutionary Biology Semester Summary Griffith University, Nathan Campus Semester 1, 2014 Topics include: - Mendelian Genetics - Eukaryotic & Prokaryotic Genes - Sex Chromosomes - Variations
More informationMULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Exam Chapter 15 Chromosomal Basis for Inheritance AP Biology Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) When Thomas Hunt Morgan crossed
More information8/31/2017. Biology 102. Lecture 10: Chromosomes and Sex Inheritance. Independent Assortment. Independent Assortment. Independent Assortment
Biology 102 Lecture 10: Chromosomes and Sex Inheritance All of our examples of inheritance patterns have focused on single genes Humans have 25,000 genes! Genes on the same chromosome are inherited together
More informationGENDER James Bier
GENDER 2005-2008 James Bier Objectives 1. State the method of determining gender in several genetic systems. 2. List the three regions of the Y chromosome. 3. Describe the events that promote sexual development
More information10/26/2015. ssyy, ssyy
Biology 102 Lecture 10: Chromosomes and Sex Inheritance All of our examples of inheritance patterns have focused on single genes Humans have 25,000 genes! Genes on the same chromosome are inherited together
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 informationReproduction Review YOU ARE EXPECTED TO KNOW THE MEANING OF ALL THE FOLLOWING TERMS:
Reproduction Review YOU ARE EXPECTED TO KNOW THE MEANING OF ALL THE FOLLOWING TERMS: CHROMOSOME GENE DNA TRAIT HEREDITY INTERPHASE MITOSIS CYTOKINESIS ASEXUAL BINARY FISSION CELL CYCLE GENETIC DIVERSITY
More informationTHE CHROMOSOMAL BASIS OF INHERITANCE CHAPTER 15
THE CHROMOSOMAL BASIS OF INHERITANCE CHAPTER 15 What you must know: Inheritance in sex-linked genes. Inheritance of linked genes and chromosomal mapping. How alteration of chromosome number or structurally
More informationGenetics - Problem Drill 06: Pedigree and Sex Determination
Genetics - Problem Drill 06: Pedigree and Sex Determination No. 1 of 10 1. The following is a pedigree of a human trait. Determine which trait this is. (A) Y-linked Trait (B) X-linked Dominant Trait (C)
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 informationBiology Unit III Exam» Form C
Directions: For each of the following questions, decide which of the choices is best and fill in the corresponding space on the answer document. 1. Which of these sets of chromosomes is found in a single
More informationChromosomes, Mapping, and the Meiosis-Inheritance Connection. Chapter 13
Chromosomes, Mapping, and the Meiosis-Inheritance Connection Chapter 13 Chromosome Theory Chromosomal theory of inheritance - developed in 1902 by Walter Sutton - proposed that genes are present on chromosomes
More informationWhat creates variation in the offspring of sexually reproducing organisms?
What creates variation in the offspring of sexually reproducing organisms? 1. genetic recombination during fertilization 2. mitotic division in body cells 62% 3. crossing over in mitosis 4. homologous
More informationPlant Reproduction fertilization
Plant Reproduction In the plant kingdom, both sexual and asexual reproduction occur. Recall from Chapter 3 that plants reproduce sexually by sporic reproduction, which is also called alternation of generations.
More information--- understanding its biological significance. -- appreciating how genetics was used to understand how it is determined.
Sex: --- understanding its biological significance -- appreciating how genetics was used to understand how it is determined. according to Jacob Bronowski in The Ascent of Man (1973) Mendel himself was
More informationBIOLOGY 3201 REPRODUCTION
BIOLOGY 3201 REPRODUCTION Asexual vs. Sexual Reproduction MODES OF REPRODUCTION (1) Asexual one parent cell divides into two by mitosis to produce 2 identical cells which are clones of the parent (2) Sexual
More informationChromosome Theory & Sex-Linked Transmission
Chromosome Theory & Sex-Linked Transmission (CHAPTER 3 & 5- Brooker Text) Feb 14, 2006 BIO 184 Dr. Tom Peavy - Maturation of the sperm in the epididymis - Mammalian sperm become capable of fertilizing
More informationREPRODUCTION IN ORGANISMS
REPRODUCTION IN ORGANISMS Reproduction: Reproduction is defined as a biological process in which an organism gives rise to young ones (offspring) similar to itself. Life span of different organisms Name
More informationBiology 321 QUIZ#3 W2010 Total points: 20 NAME
Biology 321 QUIZ#3 W2010 Total points: 20 NAME 1. (5 pts.) Examine the pedigree shown above. For each mode of inheritance listed below indicate: E = this mode of inheritance is excluded by the data C =
More informationChromosomes and Human Inheritance. Chapter 11
Chromosomes and Human Inheritance Chapter 11 11.1 Human Chromosomes Human body cells have 23 pairs of homologous chromosomes 22 pairs of autosomes 1 pair of sex chromosomes Autosomes and Sex Chromosomes
More informationHow do living things Sexually Reproduce?
How do living things Sexually Reproduce? Besides animals, what other things reproduce sexually? Think of a family that has both biological parents and has 2 or more children #1 Consider what the parents
More informationplant reproduction chapter 40 Alternation of Generations
Alternation of Generations plant reproduction chapter 40 Haploid (n) Diploid (2n) Sporangium Spore dispersal Spore (n) Young Mature (n) Archegonium Antheridium Sperm Sporangium Mature sporophyte (2n) New
More informationThe Chromosomal Basis of Inheritance
LECTURE PRESENTATIONS For CAMPBELL BIOLOGY, NINTH EDITION Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson Chapter 15 The Chromosomal Basis of Inheritance
More informationChapter 11. Chromosomes and Human Inheritance
Chapter 11 Chromosomes and Human Inheritance Human Chromosomes Human body cells have 23 pairs of homologous chromosomes 22 pairs of autosomes 1 pair of sex chromosomes Autosomesand Sex Chromosomes Paired
More informationGenetic Variation Junior Science
2018 Version Genetic Variation Junior Science http://img.publishthis.com/images/bookmarkimages/2015/05/d/5/c/d5cf017fb4f7e46e1c21b874472ea7d1_bookmarkimage_620x480_xlarge_original_1.jpg Sexual Reproduction
More informationMendelian 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 informationTopic 13 Sex. Being Male and Female
Topic 13 Sex Being Male and Female Reproduction Asexual (1 individual): more efficient, low genetic variation Sexual: prevalent (2 sexes, separate or not) High genetic variation, need 2 Approaches: External
More informationplant reproduction Alternation of Generations chapter 38
Alternation of Generations Haploid (n) plant reproduction chapter 38 Diploid (2n) Sporangium Spore dispersal Spore (n) Young Mature (n) ARCHEGONIUM ANTHERIDIUM Sperm Mature Sorus Sporangium sporophyte
More informationMuch ha happened since Mendel
Chapter 15 Chromosomal Basis of Inheritance Much ha happened since Mendel We can show genes are located at particular loci on chromosomes Using fluorescent dye to mark a particular gene 1 The use of these
More informationSexual Reproduction: Adding Variety
4.3 gamete a sex cell; includes sperm cells in males and egg cells in females fertilization the formation of a zygote by the joining together, or fusion, of two gametes zygote a cell produced by the fusion
More informationBy 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 information1.3 - Sexually Reproduction What is Sexual Reproduction?
1.3 - Sexually Reproduction What is Sexual Reproduction? Sexual Reproduction - Genetic information from two cells is combined to produce a new genetically unique organism. Sexual reproduction occurs when
More informationPatterns in Inheritance. Chapter 10
Patterns in Inheritance Chapter 10 What you absolutely need to know Punnett Square with monohybrid and dihybrid cross Heterozygous, homozygous, alleles, locus, gene Test cross, P, F1, F2 Mendel and his
More informationThe form of cell division by which gametes, with half the number of chromosomes, are produced. Chromosomes
& Karyotypes The form of cell division by which gametes, with half the number of chromosomes, are produced. Homologous Chromosomes Pair of chromosomes (maternal and paternal) that are similar in shape,
More informationGenetics Review. Alleles. The Punnett Square. Genotype and Phenotype. Codominance. Incomplete Dominance
Genetics Review Alleles These two different versions of gene A create a condition known as heterozygous. Only the dominant allele (A) will be expressed. When both chromosomes have identical copies of the
More information17. Sex. Being Male and Female
17. Sex Being Male and Female Reproduction Asexual: more efficient (Only 1 sex) Low genetic variation Sexual: prevalent (2 sexes, separate or not) High genetic variation Need 2 members of the same species
More informationReproduction 19/02/2016. Asexual Reproduction. Budding: Types of asexual reproduction: SEXUAL VS. ASEXUAL
Asexual Reproduction Reproduction SEXUAL VS. ASEXUAL One parent cell divides by mitosis to produce 2 daughter cells which are clones of the parent Types of asexual reproduction: Budding: 1. Budding 2.
More informationChapter 4 The Chromosome Theory of Inheritance
Chapter 4 The Chromosome Theory of Inheritance 4-1 Sections to study 4.1 Chromosomes: The carriers of genes 4.2 Mitosis: Cell division that preserves chromosome number 4.3 Meiosis: Cell division that halve
More informationChapter 15 Notes 15.1: Mendelian inheritance chromosome theory of inheritance wild type 15.2: Sex-linked genes
Chapter 15 Notes The Chromosomal Basis of Inheritance Mendel s hereditary factors were genes, though this wasn t known at the time Now we know that genes are located on The location of a particular gene
More informationChapter 31: Plant Reproduction
Chapter 31: Plant Reproduction Plants and Pollinators Pollen had evolved by 390 million years ago Sperm packed inside a nutritious package Transferred first by wind currents Later transferred by insects
More informationCh. 15 The Chromosomal Basis of Inheritance
Ch. 15 The Chromosomal Basis of Inheritance Nov 12 12:58 PM 1 Essential Question: Are chromosomes the basis of inheritance? Nov 12 1:00 PM 2 1902 Walter S. Sutton, Theodor Boveri, et al Chromosome Theory
More informationSpermatogenesis. I) Spermatocytogenesis: Spermatogonium Spermatid (2N, 4C) (1N, 1C) Genetic
Spermatogenesis I) Spermatocytogenesis: Spermatogonium Spermatid (2N, 4C) (1N, 1C) Genetic II) Spermiogenesis: Spermatid Spermatozoan (1N, 1C) (1N, 1C) Metamorphic - loss of cytoplasm - addition of flagellum
More informationHuman Genetics (Learning Objectives)
Human Genetics (Learning Objectives) Recognize Mendel s contribution to the field of genetics. Review what you know about a karyotype: autosomes and sex chromosomes. Understand and define the terms: characteristic,
More informationExam #2 BSC Fall. NAME_Key correct answers in BOLD FORM A
Exam #2 BSC 2011 2004 Fall NAME_Key correct answers in BOLD FORM A Before you begin, please write your name and social security number on the computerized score sheet. Mark in the corresponding bubbles
More information2/7&9/2010 Biology 321. The inheritance patterns discovered by Mendel are true for genes that are located on autosomes. What is an autosome?
2/7&9/2010 Biology 321 The inheritance patterns discovered by Mendel are true for genes that are located on autosomes What is an autosome? 1 The fly room at Columbia University ~ 1920 l to r: Calvin Bridges,
More informationREVIEW SHEET: Units 11 Meiosis, Fertilization, & Genetics
REVIEW SHEET: Units 11 Meiosis, Fertilization, & Genetics ACP BIOLOGY Textbook Reading: Meiosis & Fertilization (Ch. 11.4, 14.1-2) and Classical Genetics (Ch. 11.1-3) Handouts:! NOTES Meiosis & Fertilization!
More informationEOG Practice:,Evolution & Genetics [126663]
EOG Practice:,Evolution & Genetics [126663] Student Class Date 1. A particular peach tree produces peaches that are more resistant to disease than other peaches. What method would reproduce these EXACT
More informationChapter 38: Angiosperm Reproduction and Biotechnology
Name: Chapter 38: Angiosperm Reproduction and Biotechnology 38.1 Flowers, double fertilization, and fruits are unique features of the angiosperm life cycle This may be a good time for you to go back and
More information14 2 Human Chromosomes
14-2 Human Chromosomes 1 of 25 Sex-Linked Genes Sex-Linked Genes The X chromosome and the Y chromosomes determine sex. Genes located on these chromosomes are called sex-linked genes. More than 100 sex-linked
More informationTEST NAME:review TEST ID: GRADE:07 Seventh Grade SUBJECT:Life and Physical Sciences TEST CATEGORY: My Classroom
TEST NAME:review TEST ID:1070005 GRADE:07 Seventh Grade SUBJECT:Life and Physical Sciences TEST CATEGORY: My Classroom review Page 1 of 18 Student: Class: Date: 1. There are four blood types: A, B, AB,
More informationBiology 321. The inheritance patterns discovered by Mendel are true for genes that are located on autosomes. What is an autosome?
Biology 321 The inheritance patterns discovered by Mendel are true for genes that are located on autosomes What is an autosome? 1 The fly room at Columbia University ~ 1920 l to r: Calvin Bridges, A. sturtevant,
More informationSexual Reproduction. Chapter 3 Sexual Reproduction BC Science Probe 9 pages
Sexual Reproduction Chapter 3 Sexual Reproduction BC Science Probe 9 pages 72-105 Why Sex? Textbook Read pages 74 77 Sexual Reproduction Is reproduction involving two parents Each parent contributes equal
More informationUNIT IV. Chapter 14 The Human Genome
UNIT IV Chapter 14 The Human Genome UNIT 2: GENETICS Chapter 7: Extending Medelian Genetics I. Chromosomes and Phenotype (7.1) A. Two copies of each autosomal gene affect phenotype 1. Most human traits
More informationLECTURE 12 B: GENETIC AND INHERITANCE
LECTURE 12 B: GENETIC AND INHERITANCE Mendel s Legacy Genetics is everywhere these days and it will continue as a dominant force in biology and society for decades to come. Wouldn t it be nice if people
More information1. discovered how genes are inherited by using peas. 2. cross pollinated peas
I. Mendel & the Idea of Alleles A. Gregor Mendel 1. discovered how genes are inherited by using peas 2. cross pollinated peas 3. concentrated on 7 traits that did not fit blending theory 4. blending
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 informationThe Chromosomal Basis of Inheritance
Chapter 15 The Chromosomal Basis of Inheritance Lecture Outline Overview: Locating Genes on Chromosomes Today we know that genes Gregor Mendel s hereditary factors are located on chromosomes. A century
More informationREVIEW SHEET: Units 11 Meiosis, Fertilization, & Genetics
REVIEW SHEET: Units 11 Meiosis, Fertilization, & Genetics HONORS BIOLOGY Textbook Reading: Meiosis & Fertilization (Ch. 11.4, 14.1-2) and Classical Genetics (Ch. 11.1-3) Handouts:! NOTES Meiosis & Fertilization!
More informationThe Living Environment Unit 3 Genetics Unit 11 Complex Inheritance and Human Heredity-class key. Name: Class key. Period:
Name: Class key Period: Chapter 11 assignments Pages/Sections Date Assigned Date Due Topic: Recessive Genetic Disorders Objective: Describe some recessive human genetic disorders. _recessive_ alleles are
More informationPRINCIPLES OF INHERITANCE AND VARIATION
CHAPTER 5 PRINCIPLES OF INHERITANCE AND VARIATION POINTS TO REMEMBER Allele : Various or slightly different forms of a gene, having same position on chromosomes. Phenotype : The observable or external
More informationThe Discovery of Chromosomes and Sex-Linked Traits
The Discovery of Chromosomes and Sex-Linked Traits Outcomes: 1. Compare the pattern of inheritance produced by genes on the sex chromosomes to that produced by genes on autosomes, as investigated by Morgan.
More informationBiology 321. Ì The inheritance patterns discovered by Mendel are true for genes that are located on autosomes. Ì What is an autosome?
Biology 321 Ì The inheritance patterns discovered by Mendel are true for genes that are located on autosomes Ì What is an autosome? 1 The fly room at Columbia University ~ 1920 l to r: Calvin Bridges,
More informationChapter 7 DEVELOPMENT AND SEX DETERMINATION
Chapter 7 DEVELOPMENT AND SEX DETERMINATION Chapter Summary The male and female reproductive systems produce the sperm and eggs, and promote their meeting and fusion, which results in a fertilized egg.
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 informationREADING ASSIGNMENT GENETIC ANALYSIS OF DROSOPHILA POPULATIONS I. HOW DO MITOSIS AND MEIOSIS COMPARE?
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
More informationBell Work 3/8/18. Mitosis: What occurs during mitosis? What are the products of mitosis? What is the purpose of mitosis?
Bell Work 3/8/18 Mitosis: What occurs during mitosis? What are the products of mitosis? What is the purpose of mitosis? Bell Work: 3/9/18 Complete the pre-assessment on your Anchor Activity Unit 6 sheet.
More informationAS90163 Biology Describe the transfer of genetic information Part 1 - DNA structure & Cell division
AS90163 Biology Describe the transfer of genetic information Part 1 - DNA structure & Cell division This achievement standard involves the description of the transfer of genetic information. Achievement
More informationChromosomal Abnormalities and Karyotypes Creating a Karyotype
Chromosomal Abnormalities and Karyotypes Creating a Karyotype The Normal Human Karyotype The normal human karyotype is composed of SEVEN groups of chromosomes A G plus the sex chromosomes X and Y. The
More informationWhy do cells reproduce?
Outline Cell Reproduction 1. Overview of Cell Reproduction 2. Cell Reproduction in Prokaryotes 3. Cell Reproduction in Eukaryotes 1. Chromosomes 2. Cell Cycle 3. Mitosis and Cytokinesis Examples of Cell
More informationDownloaded 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 informationChapter 15: The Chromosomal Basis of Inheritance
Name Period Chapter 15: The Chromosomal Basis of Inheritance Concept 15.1 Mendelian inheritance has its physical basis in the behavior of chromosomes 1. What is the chromosome theory of inheritance? 2.
More informationThe Chromosomal Basis Of Inheritance
The Chromosomal Basis Of Inheritance Chapter 15 Objectives Explain the chromosomal theory of inheritance and its discovery. Explain why sex-linked diseases are more common in human males than females.
More informationMEIOSIS: Genetic Variation / Mistakes in Meiosis. (Sections 11-3,11-4;)
MEIOSIS: Genetic Variation / Mistakes in Meiosis (Sections 11-3,11-4;) RECALL: Mitosis and Meiosis differ in several key ways: MITOSIS: MEIOSIS: 1 round of cell division 2 rounds of cell division Produces
More informationAP Biology Chapter 15 Notes The Chromosomal Basis of Inheritance
AP Biology Chapter 15 Notes The Chromosomal Basis of Inheritance I. Chapter 15.1: Mendelian inheritance has its physical basis in the behavior of chromosomes. a. Chromosome theory of inheritance: i. Mendelian
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 informationThe Chromosomal Basis of Inheritance
Chapter 15 The Chromosomal Basis of Inheritance PowerPoint Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley with contributions
More informationCHROMOSOMAL NUMERICAL ABERRATIONS INSTITUTE OF BIOLOGY AND MEDICAL GENETICS OF THE 1 ST FACULTY OF MEDICINE
CHROMOSOMAL NUMERICAL ABERRATIONS INSTITUTE OF BIOLOGY AND MEDICAL GENETICS OF THE 1 ST FACULTY OF MEDICINE CHROMOSOMAL ABERRATIONS NUMERICAL STRUCTURAL ANEUPLOIDY POLYPLOIDY MONOSOMY TRISOMY TRIPLOIDY
More informationReproduction in Organisms
Reproduction in Organisms Asexual Reproduction The period through which a certain organism lives is known as its life span. Reproduction is the process by which every organism ensures its continuity. It
More informationLesson Overview Human Chromosomes
Lesson Overview 14.1 Human Chromosomes Human Genome To find what makes us uniquely human, we have to explore the human genome, which is the full set of genetic information carried in our DNA. This DNA
More informationGenetics: 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 informationEvolution of gender Sex ratio how many males and females? Sex determination how did they get to be male/female? Some truly weird animals
1 Roadmap Finishing up inbreeding Evolution of gender Sex ratio how many males and females? Sex determination how did they get to be male/female? Some truly weird animals 2 Midterm Mean 72.6 Range 35-92
More informationSex chromosomes and sex determination
Sex chromosomes and sex determination History (1) 1940-ties Alfred Jost embryo-surgical experiments on gonads gonadal sex; male gonadal sex presence of testes; female gonadal sex lack of testes. History
More informationGenetic diagrams show the genotype and phenotype of the offspring of two organisms. The different generation are abbreviated like so:
Genetics 2 Genetic Diagrams and Mendelian Genetics: Genetic diagrams show the genotype and phenotype of the offspring of two organisms. The different generation are abbreviated like so: P parent generation
More information12 Biology Revision Notes - Term 3
QCE Biology Year 2016 Mark 0.00 Pages 21 Published Jan 24, 2017 Revision Notes - Term 3 By Sophie (1 ATAR) Powered by TCPDF (www.tcpdf.org) Your notes author, Sophie. Sophie achieved an ATAR of 1 in 2016
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 information.Protein LYONIZATION. The process by which all X chromosomes in excess of one are made genetically inactive and heterochromatic.
+ Electrical field - LYONIZATION Colleen Jackson-Cook, Ph.D, FACMG Sanger Hall, Room 5-7 ccook@mcvh-vcu.edu The process by which all X chromosomes in excess of one are made genetically inactive and heterochromatic.
More informationLecture 17: Human Genetics. I. Types of Genetic Disorders. A. Single gene disorders
Lecture 17: Human Genetics I. Types of Genetic Disorders A. Single gene disorders B. Multifactorial traits 1. Mutant alleles at several loci acting in concert C. Chromosomal abnormalities 1. Physical changes
More informationCellular Reproduction Chapter 8
Cellular Reproduction Chapter 8 1. Importance of Cell Division 2. Eukaryotic Cell Cycle 3. Eukaryotic Chromosomes 4. Mitosis 5. Cytokinesis in animal and plant cells 6. Sexual Iife cycle 7. Meiosis 8.
More informationRelating Mendelian Inheritance to the Behavior of Chromosomes
Chapter 15 Relating Mendelian Inheritance to the Behavior of Chromosomes 1. Explain how the observations of cytologists and geneticists provided the basis for the chromosome theory of inheritance. 2. Explain
More informationNOTES- CHAPTER 6 CHROMOSOMES AND CELL REPRODUCTION
NOTES- CHAPTER 6 CHROMOSOMES AND CELL REPRODUCTION Section I Chromosomes Formation of New Cells by Cell Division New cells are formed when old cells divide. 1. Cell division is the same as cell reproduction.
More informationCHROMOSOMES. The Human Genome Project: Biocomputing Admin Ed Yung
CHROMOSOMES The Human Genome Project: Biocomputing Admin Ed Yung Chromosomes in eukaryotes and prokaryotes are different PROKARYOTES single chromosome plus plasmids circular chromosome made only of DNA
More information3. What law of heredity explains that traits, like texture and color, are inherited independently of each other?
Section 2: Genetics Chapter 11 pg. 308-329 Part 1: Refer to the table of pea plant traits on the right. Then complete the table on the left by filling in the missing information for each cross. 6. What
More informationLab Activity 36. Principles of Heredity. Portland Community College BI 233
Lab Activity 36 Principles of Heredity Portland Community College BI 233 Terminology of Chromosomes Homologous chromosomes: A pair, of which you get one from mom, and one from dad. Example: the pair of
More informationQB365 Important Questions - Principles of Inheritance and Variation
QB36 Important Questions - Principles of Inheritance and Variation th Standard CBSE Biology Reg.No. : Time : 0:00:00 Hrs Section - A ) Heterozygous purple flower is crossed with recessive white flower.
More informationUnit 4: Reproduction Chapter 6. Meiosis is the basis of sexual reproduction.
Unit 4: Reproduction Chapter 6 Meiosis is the basis of sexual reproduction. Mitosis Recap https://www.youtube.com/watch?v= JayldCyv5eQ Sexual Reproduction Section 6.1: Meiosis Sexual Reproduction: a method
More information