Biology 1001A Chapter Notes - Chapter 11: Testis Determining Factor, Y Chromosome, Chromosome

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silverwolf688

25 Nov 2016

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Chapter 11 genes chromosomes and human genetics. Sex linked genes: genes located on sex chromosomes. 11. 2a females are xx and males are xy in both humans and fruit flies. Males have 1 x chromosome and 1 y chromosome. 11. 2b human sex determination depends on the sry gene. Sry gene sex determining region of the y chromosome (switch that directs development towards maleness) 11. 2c sex-linked genes were first discovered in drosophila (fruit flies) Sex linkage: how genes on sex chromosomes act (it is different then mendelian patterns) Males have one copy of the x chromosome and therefore only one allele for genes on the x chromosome. So the genes on that chromosome are only ever expressed in men. 11. 2d sex linked genes in humans are inherited as they are in drosophila. Pedigree: shows all parents and offspring for as many generations as possible the sex of individuals in the different generations, and the presence or absence of the trait of interest.

Related Questions

Complete the following paragraph to learn about x-linked inheritance. expressed, men, sex-linked, ... Question: Complete the following paragraph to learn about X-linked inheritance. expressed, men, sex-linked,... Complete the following paragraph to learn about X-linked inheritance. expressed, men, sex-linked, repressed, X, Y, autosomal, two, one Sex-linked alleles have a different pattern of inheritance compared to those found on ____________ chromosomes. This is because on ____________ alleles, the allele is only carried on the X chromosome and not the Y chromosome. That means that females can pass down diseased alleles to offspring through ____________ ____________ chromosomes, while males can pass down alleles through ____________ ____________ chromosome. For this reason, it is more likely that ____________ are afflicted with sex-linked diseases, because whatever allele is carried on their ____________ ____________ chromosome is ____________ .

11) CIRCLE ALL CORRECT ANSWERS: Human males are hemizygous for

a) Sxl gene b) pseudoautosomal region of the Y c)SRY d) gene for testis determining factor e) Xist gene

12) The X inactivation center codes for

a) gonadal ridges to form ovaries b) gonadal ridges to form testes c) RNA d) testosterone e) protein enhancing transcription of sex linked genes

13) CIRCLE ALL CORRECT ANSWERS: The pseudoautosomal region is found on

a) autosomes in males b) autosomes in females c) X chromosome d) Y chromosome e) both the X and Y chromosome f) could occur in fruit flies

14) Comparing two monozygotic XX twins to two monozygotic XY twins

a) XX are more identical b) XY are more identical c) monozygotic twins do not occur

EXPLAIN YOUR ANSWER:

15) CIRCLE ALL CORRECT ANSWERS: Butterflies and Habrobracon differ in

a) which sex is homogametic b) which sex is monoploid c) one has sex chromosomes and the other does not d) one produces some gametes by mitosis, the other does not

1. What is the chromosome theory of inheritance?

2. Understand how independent assortment can cause gametes to have four combinations of alleles when an individual is heterozygous for two genes on two different chromosomes.

3. What are linked characters and linked genes? Understand why linked genes will not independently assort.

4. How can crossing over affect linked genes?

5. What are recombinant gametes?

6. Define recombinant frequency. Be able to use the recombinant frequency to determine how close two genes are on a chromosome.

7. What is a linkage map?

8. What is the function of the SRY gene on the Y chromosome? What happens if you don't have this gene?

9. Know how sex is determined in mammals, birds, bees and ants, and reptiles.

10. How many autosomes and sex chromosomes do normal human haploid and diploid cells have?

11. What does it mean for a gene to be X-linked or Y-linked?

12. Be able to answer word problems and fill out a Punnet square involving an X-linked recessive trait.