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Flashcards in gen EXAM Deck (52):
1

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

xoderma pigmentosa
recessive

2

lacking the enzyme to digest milk sugar

galactosemia
recessive

3

About 1 in every 500 black people develops this condition

sickle cell
recessive

4

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

albinism
recessive

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

tay-sachs
RECESSIVE

6

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

pku
recessive

7

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

cystic fibrosis
recessive

8

Affected individuals produce abnormal hemoglobin

sickle cell
recessive

9

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

thalassemia
recessive

10

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

marfans
dominant

11

This condition is commonly known as "dwarfism"

achondroplasia
dominant

12

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

huntingtons disease
DOMINANT

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.

familial hypercholestorolemia
DOMINANT

14

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

neurofibromatosis
dominant

15

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

hemophilia SEX LINKED X recessive

16

Phenotypic ratio of dihybrid cross

9 3 3 1

17

Phenotypic ratio of monohybrid cross

3 1

18

Genotypic ratio of monohybrid cross

1 2 1

19

Genotypic ratio of dihybrid cross

1 2 1 2 4 2 1 2 1

20

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

The Law of Independent Assortment

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

sex linked

22

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

zygote

23

Male pseudohermaphroditism describes a

female exterior, male interior and male chromosome constitution

24

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

pseudoautosomal
(parts on both, act as autosomal)

25

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

true

26

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

sex limited
beard and milk

27

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

sex influenced
baldness

XX Xx xx

28

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

true

29

The presence of a Y chromosome in early embryogenesis causes

the indifferent gonad to become a testis

30

The underlying cause of pseudohermaphroditism is

a lack or receptors in cells to recognize male hormones

31

XX SRY+

phenotypic male

32

XY SRY-

phenotypic female

33

gene in humans that determines gender

SRY

34

gene that inactivates or coils autosomal chromatin

MIX

35

gene that inactivates or coils the X into a Barr body

XIST

36

area on Y chromosome that does not recombine

NRY

37

Fragile X Syndrome is caused by

an X chromosome deletion

38

The ratio of males to females __________ over a lifetime.

decreases

39

Heterochromatin (or lack of) is responsible for

Turner's Syndrome symptoms

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

a bipotential gonad

41

A true hermaphrodite results from

fusion of fraternal twin embryos

42

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

mullerian system

43

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

mullerian

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

there was no Mullerian Inhibiting Hormone secreted by the testes

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

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

46

If a population is in Hardy-Weinberg equilibrium, then

the proportionof all genotypes will remain constant

47

The Hardy-Winberg principle applies only to populations that

are not acted on by agents of change

48

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

all on different chromosomes

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

remain constant

50

What is condition of colorblind

X recessive

51

Holandric traits are

carried only by males and transmitted only to males

52

Beard growth in humans is an example of a _____ trait

sex limited