Genetics test

Question 1

How many chromosomes are in a normal gamete

Answer 1

23

Question 2

What are autosomes

Answer 2

22 pairs of identical chromosomes

Question 3

What are histones

Answer 3

structural proteins used to form chromosomes

Question 4

What does the centromere do

Answer 4

divides the chromosome into short arm (p) and long arm (q)

Question 5

What is metacentric

Answer 5

when the chromosomes have equal arm lenth

Question 6

What is submetacentric

Answer 6

when the chromosomes have one arm longer than the other

Question 7

What is acrocentric

Answer 7

When the p arm (short) contains such small amounts of genetic material that it is almost negligible

Question 8

What is advanced maternal age

Answer 8

pregnant women who will be 35 or older on their expected date of confinement

Question 9

How many sets of chromosmes do triploidy fetuses have? Total? How does this normally happen?

Answer 9

3 sets of chromosomes, totally 69. They are rarely born alive and come from 2 sperm fertilization

Question 10

How many sets of chromosomes do tetraploidy fetuses have? Total? When do they miscarry?

Answer 10

4 sets of chromosomes, totally 96. They miscarry in the first trimester

Question 11

What is an aneuploid? Examples?

Answer 11

any genotype in which the total chromosome number is not a multiple of 23. Example: monosomy and trisomy

Question 12

What is meiotic nondisjunction

Answer 12

a pair of chromosomes fail to separate during either of the meiotic divisions

Question 13

What are the two categories of structural abnormalities

Answer 13

balanced and unbalanced

Question 14

What is a balanced structural abnormality

Answer 14

has normal amount of chromosomal material and has functional centromere with 2 functioning telomeres

Question 15

What is an unbalanced structural abnormality

Answer 15

chromosome has missing or extra genetic info

Question 16

What is Robertsonian translocation

Answer 16

where 2 chromosomes lose short arem and fuse near centromeric region, this leads to balanced karyotypes with 45 chromosomes (leads to trisome 21 offspring)

Question 17

What are alleles

Answer 17

variants of a gene

Question 18

What are wild-type alleles

Answer 18

one prevailing allele for a gene

Question 19

What is de novo

Answer 19

neither parent possessed the mutation

Question 20

If both parents are carriers of an autosomal recessive condition, what percentage of their offspring with have the disease

Answer 20

25%

Question 21

What are consanguineous unions

Answer 21

mating between individuals who are second cousins or closer ( there is an increased risk of autosomal recessive disorders)

Question 22

Who are x-linked recessive mutations expressed in? Examples?

Answer 22

Expressed in all males and homozygous females, passed on by females

Question 23

From which side is mitochondrial DNA inherited from

Answer 23

maternal, sperm mitochondria are eliminated from the forming embryo

Question 24

Mitochondrial diseases typically manifest as dysfunction in what organs

Answer 24

high-consuming organs: brain, muscle, heart, and kidneys

Question 25

Symptoms of Prader-Willi

Answer 25

Hypotonia, low birth weight, almond-shaped eyes, short, indiscriminate eating habits, mental retardation and hypogonadism