chromosome variation

Question 1

aneuploidy

Answer 1

2n+1 =7

Question 2

Types of rearrangement

Answer 2

duplication
Deletion
Inversion
Translocation

Question 3

dupliocation arises from — between synapsed chromosomes in meoisis

Answer 3

unequal crossing over

Question 4

effect of duplication

Answer 4

increased gene dosage
nw genes with distinct gene products

Question 5

effect of deletion

Answer 5

pseudominance
imbalance in gene product

Question 6

paracentric means

Answer 6

inversions do not include centromere

Question 7

pericentric means

Answer 7

inversion includes centromere

Question 8

effect of inversion in individual homozygous

Answer 8

no problems arise in meoisis

Question 9

effect of imversion in individuals heterozygous

Answer 9

homologous sequences align only if two chromosomes from an inversion loop
abnormal gametes form if recombination is in inverted regions

Question 10

a single crossover within paracentric inversion leads to

Answer 10

abnormal recombination gametes

Question 11

effect single crossover in paracentric inversion

Answer 11

suppress recombination in inverted region

Question 12

types of translocations

Answer 12

1. Non reciprocal
   reciprocal
   robertsonian translocation

Question 13

example of disease causing reciprocal translocation

Answer 13

burkitt lymphoma

Question 14

what is burkitt lymphoma

Answer 14

cancer of B cells, which are lymphocytes making antibodies

Question 15

c-MYC stimulates

Answer 15

cell division

Question 16

translocation of B-cells does what

Answer 16

puts c-MYC behind immunoglobin gene leading to high expression of c-MYC

Question 17

high expression of c-MYC leads to

Answer 17

cell division out of control

Question 18

describe robertsonian translocation

Answer 18

when the short arm of one acrocentric centrosome is exchanged for the long arm of another
leading to a large metacentric chromosmes
and a fragment taht often fails to segegrate and is losy

Question 19

causes of aneuploidy

Answer 19

robertsonian translocation
deletion of centromere during mitosis and meiosis
nondisjunction during meiosis and mitosis

Question 20

trisomy 21 results in

Answer 20

down syndrome

Question 21

which down syndrome has 75% random nondisjunction in egg formartion

Answer 21

primary down syndrome

Question 22

which down syndrome is robertsonian translocation between chromosome 14 and 21

Answer 22

familial down syndrome

Question 23

when does nondisjunction occur

Answer 23

meiosis I or II, mitosis if sister chromatids fails to seperate

Question 24

non disjunction give rise to

Answer 24

variation in chromosmal number

Question 25

loss of both members of a homologous pair of chromosmes

Answer 25

nullisomy, 2n-2

Question 26

loss of a single chromosome

Answer 26

monosomy, 2n-1

Question 27

gain of a single chromosome

Answer 27

2n+1, trisomy

Question 28

gainof two homologous chromosomes

Answer 28

tetrasony, 2n+_2

Question 29

if a parent who is a 14-21 translocation carrier mates with a normal person, what is teh pheinotypes of offspring

Answer 29

2/3 will have normal phenotype including translocation carrier 1/3 will have down syndrome, others die

Question 30

explain aneuploidy and maternal age

Answer 30

older mothers are more likely to give birth toi a child with down syndrome

Question 31

significance of polyploidy

Answer 31

increase in cell size larger plant attributes Evolution many crop plantys are polyploid

Question 32

how many nuclei does skeletal muscle have

Answer 32

multiple nuclei

Question 33

when do myoblasts fuse

Answer 33

as muscle cells form

Question 34

what is disjunction

Answer 34

paired homologs fail to disjoin during segregation