Log in
HomeClass Notes1,200,000CA670,000

BIOL 1000 Lecture Notes - Lecture 12: Sex Linkage, Y Chromosome, Chromosome

23 views4 pages
pucegoat339
21 Feb 2019
School
York University
Department
Biology
Course
BIOL 1000
Professor
Angelo Belcastro

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

After 6-8 weeks of embryonic development, the sry gene becomes active in. Males have one x chromosome, so one allele for each gene on this chromosome. While females have two x chromosomes, so two alleles for all genes on the x chromosome. Males have one copy of y chromosome and one allele for each gene on this chromosome. While females do not have a y chromosome, so no y alleles: sex linkage was discovered when morgan crossed a white-eyed male fly with a true-breeding female with red eyes. He observed that all the f1 flies had red eyes. Next, he allowed the f1 flies to interbreed. He found that all the f2 females had red eyes and half of the f2 males had red eyes and half had white eyes. Chapter 12: genes, chromosomes, and human genetics 2: reciprocal cross was always made between a white-eyed female fly with a red-eyed male fly.

Get access

Grade+
$40 USD/m
Billed monthly
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
10 Verified Answers
Class+
$30 USD/m
Billed monthly
Class+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
7 Verified Answers

Related Documents

BIOL 1000 Chapter Notes - Chapter 11: X-Inactivation, Y Chromosome, Genetic Linkage
beigerabbit492
BIOL 1000 Chapter Notes - Chapter 11: Cri Du Chat, X-Inactivation, Testis Determining Factor
bronzefox554
BIOL 1000
Final Exam
Study Guide
BIOL 1000 Study Guide - Midterm Guide: Y Chromosome, Barr Body, Centimorgan
harlequinmanatee745

Related Questions

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

According to the multiplication rule of probability, the chance of crossing two pea plants that are heterozygous for height and have none of four offspring showing the recessive short phenotype is:A. ¼ × ¼ × ¼ × ¼.

B. ¾ × ¾ × ¾ × ¾.

C. (¼ × ¼ × ¼ × ¼) + (¾ × ¾ × ¾ × ¾).

D. ¼ + ¼ + ¼ + ¼.

E. None of the above.

What characteristic is exhibited by an X-linked trait?

a) Only females have the trait.
b) Females inherit X-linked traits from their maternal parent only.
c) Females can inherit a gene for an X-linked trait from either parent.

d) Males inherit X-linked traits from their paternal parent only.

e) Males can inherit a gene for an X-linked trait from either parent but normally inherit it from their fathers.
What characteristic is exhibited by a Y-linked trait?
a) Y-linked traits appear only in male offspring of men with the trait.
b)Y-linked traits are only passed from father to son.
c) Y-linked traits can be passed from mother to son.
d) Both A and B are characteristics of Y-linked traits.
e) Both A and C are characteristics of Y-linked traits.
Which of the following codes for a phenotypic human male?
a) XO with a copy of SRY gene on an autosomal chromosome?
b) XXYY with one copy of the SRY gene deleted?
c) XX with a copy of SRY gene on an autosomal chromosome?
d) All of the above sex compliments results in a person with a sex phenotype of male.
e) XY with the SRY gene located on an autosomal chromosome?
In Drosophila, yellow body is due to an X-linked gene (Xy) that is recessive to the gene for gray body (X+). A homozygous gray female is crossed with a yellow male. What are the genotypes of the F1 progeny?
In some goats, the presence of horns is produced by an autosomal gene that is dominant in males and recessive in females. A horned female is crossed with a hornless male. The F1 offspring are intercrossed to produce the F2. What proportion of the F2 females will have horns?
a)1/2
b)3/4
c)1/4
d) All
None
a) Females are X+X+; males are X+Y.
b)Females are X+X+; males are XyXy.
c)Females are X+X+; males are XyY.
d) Females are X+Xy; males are XyY.
e) Females are X+Xy; males are X+Y.

Females inherit X-linked traits from their maternal parent only.
Females can inherit a gene for an X-linked trait from either parent.
Males inherit X-linked traits from their paternal parent only.
Males can inherit a gene for an X-linked trait from either parent but normally inherit it from their fathers.
Males can inherit a gene for an X-linked trait from either parent but normally inherit it from their fathers.

I'll be thankful if someone can help me to do this!

According to this:

Read the following New York Times article and then answer the questions below and then answer the questions New Clues to Sex Anomalies in How Y Chromosomes Are Copied

http://www.nytimes.com/2009/09/15/science/15chrom.html?scp=1&sq=sex%20anomalies&st=cse

This activity contains 5 questions.

1. When discarding bad genes, what does the Y chromosome recombine with?
the other Y chromosome
the compliment X chromosome
itself
nothing
2. What holds a pair of copied chromosomes together?
chromatid
centrosome
centromere
chromatin
3. A person with Turner's syndrome has which of the following?
a single X chromosome
two X chromosomes
a single Y chromosome
two Y chromosomes
4. Where is the male-determining gene on the Y chromosome?
close to the end of the right arm
close to the end of the left arm
near the middle of the right arm
near the middle of the left arm

5.

Briefly explain how an individual can have some cells with no Y chromosome and other cells with a double-Y chromosome . (in your response, go beyond the article, search the web, use experiences from your life, broaden your horizons)

You must make 2 reflective, thoughtful, deep, constructive critiques of your class mates posts. as part of a threaded discussion following their initial post. The critiques must not about you, but about science!

Here's the first peson. Needs to reply for some of her answers as it says above.

1. When discarding bad genes, the Y chromosomes recombines with itself.

2. The centromere functions to hold a pair of copied chromosomes together.

3. A person with Turner’s syndrome is born with a single X chromosome.

4. The male-determining gene on the Y chromosome is located close to the end of the left arm.

5. An individual can have some cells with no Y chromosomes and other cells with double Y chromosomes, due to the differing variants present in regards to the genotypes of the cells in a single individual. When the Y chromosome is compared to other chromosomes such as the X chromosome, mutations and deviation in the distance of the centromere are much more prevalent due to the Y chromosome lacking a backup system to promote repairs.1 (Links to an external site.) Even if a mutation caused a condition such as the XYY syndrome where two Y chromosomes are present, that mutation and genotype would not be present in every single cell of the individual.2 (Links to an external site.) The presence of different genotypes offers an tentative explanation to as why a single individual can have some cells with no Y chromosomes while also housing other cells with double Y chromosomes.

Source 1 http://www.nytimes.com/2009/09/15/science/15chrom.html

Source 2 https://www.healthline.com/health/xyy-syndrome

Here's the second person. Needs to do the same as it says above.

1. Itself

2. Centromere

3. A single X chromosome

4. Close to the end of the left arm

5. Briefly explain how an individual can have some cells with no Y chromosome and other cells with a double-Y chromosome.

In some cases, the Y chromosome reaches over to a neighboring counterpart and the two chromosomes fuse. This results in the loss of part of the chromosome. Jacob’s Syndrome is sometimes also called XYY syndrome because the person has two Y chromosomes. Although a person can survive with this genetic mutation, some physical traits may be observed such as taller than average height, weak muscle development or late speech development.

Source 1 https://www.healthline.com/health/xyy-syndrome

Source 2 http://www.isna.org/faq/y_chromosome