gen EXAM

Question 1

Inability to correct thymine dimers caused by the sun’s rays

Answer 1

xoderma pigmentosa

recessive

Question 2

lacking the enzyme to digest milk sugar

Answer 2

galactosemia

recessive

Question 3

About 1 in every 500 black people develops this condition

Answer 3

sickle cell

recessive

Question 4

This conditionis caused by a block in the biochemical pathway leading to the production of melanin

Answer 4

albinism

recessive

Question 5

Nearly 1 out of every 25 American Jews carries the gene which causes this condition; caused by a buildup of lipids in the brain

Answer 5

tay-sachs

RECESSIVE

Question 6

Newborn babies can be screened for this condition by testing for the presence of high amounts of phenylalanine in the blood

Answer 6

pku

recessive

Question 7

This condition results in the accumulation of abnormally high amounts of mucus in the lungs and pancreas

Answer 7

cystic fibrosis

recessive

Question 8

Affected individuals produce abnormal hemoglobin

Answer 8

sickle cell

recessive

Question 9

Affected individuals produce little hemoglobin; homozygous recessives die within the womb

Answer 9

thalassemia

recessive

Question 10

Some characteristics of this disorder include extra long fingers, weak connective tissue and sometimes heart defects

Answer 10

marfans

dominant

Question 11

This condition is commonly known as “dwarfism”

Answer 11

achondroplasia

dominant

Question 12

This disorder is characterized by a gradual deterioration of the nervous system

Answer 12

huntingtons disease

DOMINANT

Question 13

Victims of this condition accumulate unusually high amounts of lipids in their blood and may sometimes suffer heart attacks before the age of 10.

Answer 13

familial hypercholestorolemia

DOMINANT

Question 14

The “Elephant Man” Disease; mutation causes tumors to grow along nerves

Answer 14

neurofibromatosis

dominant

Question 15

what kind of affect is hemophilia… What is it on.

Answer 15

hemophilia SEX LINKED X recessive

Question 16

Phenotypic ratio of dihybrid cross

Answer 16

9 3 3 1

Question 17

Phenotypic ratio of monohybrid cross

Answer 17

3 1

Question 18

Genotypic ratio of monohybrid cross

Answer 18

1 2 1

Question 19

Genotypic ratio of dihybrid cross

Answer 19

1 2 1 2 4 2 1 2 1

Question 20

The idea that chromosomes are not affected by other chromosomes in meiosis is called

Answer 20

The Law of Independent Assortment

Question 21

A study of a trait in a large number of families showed that 50% of the boys and none of the girls exhibited this trait. The gene for this trait is most likely

Answer 21

sex linked

Question 22

The genotypes of XY would normally be found in a(n)

Answer 22

zygote

Question 23

Male pseudohermaphroditism describes a

Answer 23

female exterior, male interior and male chromosome constitution

Question 24

If a gene is carried by both the X and Y chromosome, the mode of inheritance would be

Answer 24

pseudoautosomal

parts on both, act as autosomal

Question 25

t or f...Genes on the Y chromosome are responsible for testis differentiation.

Answer 25

true

Question 26

on specific x or y for males and females,, guy hormones or female hormones

Answer 26

sex limited | beard and milk

Question 27

autosomal,, and is affected by hormones. needs specific hormones to make it

Answer 27

sex influenced baldness XX Xx xx

Question 28

t or f....Most human females are chromosomal mosaics.

Answer 28

true

Question 29

The presence of a Y chromosome in early embryogenesis causes

Answer 29

the indifferent gonad to become a testis

Question 30

The underlying cause of pseudohermaphroditism is

Answer 30

a lack or receptors in cells to recognize male hormones

Question 31

XX SRY+

Answer 31

phenotypic male

Question 32

XY SRY-

Answer 32

phenotypic female

Question 33

gene in humans that determines gender

Answer 33

SRY

Question 34

gene that inactivates or coils autosomal chromatin

Answer 34

MIX

Question 35

gene that inactivates or coils the X into a Barr body

Answer 35

XIST

Question 36

area on Y chromosome that does not recombine

Answer 36

NRY

Question 37

Fragile X Syndrome is caused by

Answer 37

an X chromosome deletion

Question 38

The ratio of males to females __________ over a lifetime.

Answer 38

decreases

Question 39

Heterochromatin (or lack of) is responsible for

Answer 39

Turner's Syndrome symptoms

Question 40

For the first 49 days after conception, embryonic sexual tissue/structures are ambiguous. The same tissue that has the ability to become the testes, can become the ovaries. This tissues is said to be

Answer 40

a bipotential gonad

Question 41

A true hermaphrodite results from

Answer 41

fusion of fraternal twin embryos

Question 42

In mice, the gonadal tissue of a female was removed before differentiation. This mouse will develop

Answer 42

mullerian system

Question 43

In mice, the gonadal tissue of a male was removed before differentiation. This mouse will develop

Answer 43

mullerian

Question 44

In mice, the gonadal tissue of a male was removed before differentiation. This mouse was injected with testosterone. It was expected that the mouse would develop the Wolffian System only, however the Mullerian System also developed. The presence of the Mullerian System occurred because

Answer 44

there was no Mullerian Inhibiting Hormone secreted by the testes

Question 45

In mice, the gonadal tissue of a male was removed from the left side before differentiation. On the left side, both the Mullerian and Wolffian Systems developed, while on the right side, only the Wolffian System developed. This indicates that

Answer 45

testosterone is secreted via the blood, while MIH is secreted directly into surrounding tissue

Question 46

If a population is in Hardy-Weinberg equilibrium, then

Answer 46

the proportionof all genotypes will remain constant

Question 47

The Hardy-Winberg principle applies only to populations that

Answer 47

are not acted on by agents of change

Question 48

Mendel’s theories were successful because the pea plant genes he looked at were

Answer 48

all on different chromosomes

Question 49

The Hardy–Weinberg states that allele and genotype frequencies in a population will ______________from generation to generation in the absence of other outside influences

Answer 49

remain constant

Question 50

What is condition of colorblind

Answer 50

X recessive

Question 51

Holandric traits are

Answer 51

carried only by males and transmitted only to males

Question 52

Beard growth in humans is an example of a _____ trait

Answer 52

sex limited