Class 6

Question 1

How many rounds of division takes place during meiosis and what happens?

Answer 1

2 rounds

1: 1n2x homologous pairs are separated and haploid
2: 1n1x sister chromatids are separated and haploid

Question 2

What is n and x in G1, G2 and S?

Answer 2

G1: 2n1x (homologous pair)
S: same as G1
G2: 2n2x (sister chromatids)

Question 3

What happens in prophase I?

Answer 3

longest phase of meiosis
-synapsis when homologous pairs up and recombination happens to exchange DNA
-Spindle formatin
-Condense DNA
Nuclear envelop disappears

Question 4

What happens in metaphase I?

Answer 4

Chromosome tetrads align in the centre randomly

Question 5

What is a tetrad?

Answer 5

Homologous pair and sister chromatids

Question 6

What happens in anaphase I?

Answer 6

Homologous chromosome separated (becomes haploid)

Cytokinesis

Question 7

What happens in telophase I?

Answer 7

Reform nuclear envelope 
Un-condense DNA
Break down of spindle
Finish cytokinesis
-haploid 1n2x

Question 8

What happens in prophase II?

Answer 8

Separating sister chromatids
Same as prophase I
No crossing of info

Question 9

What happens in metaphase II?

Answer 9

Separating sister chromatids

Question 10

What happens in anaphase II?

Answer 10

Same as anaphase I

Question 11

What happens in telophase II?

Answer 11

Becomes 1n1x

Question 12

What is the end result of meiosis?

Answer 12

4 daughter cells that are all difference from each other and parents

Question 13

What is a nondisjunction?

Answer 13

Failure to properly separate DNA during gamete formation

Question 14

What are the 2 phases that a nondisjunction can occur?

Answer 14

Anaphase I: All 4 daughter cells will be abnormal gametes

Anaphase II: 2 daughter cells will be abnormal gametes

Question 15

What is a gene?

Answer 15

Piece of DNA that codes for some produce (includes all regulatory regions)

Question 16

What is an allele?

Answer 16

A version of a gene

Question 17

What is a trait?

Answer 17

Physical characteristics resulting from genes

Question 18

What is polymorphic?

Answer 18

Traits that come in several variations and don’t addict ability to survive

Question 19

What is polygenic?

Answer 19

A trait determined by several genes and is important for survival

Question 20

What is incomplete dominance

Answer 20

hetero offspring from homo parents have a blended phenotype

Question 21

What is codominance?

Answer 21

Both alleles are expressed at the same time and independently

Question 22

What is the universal donor and acceptor of blood?

Answer 22

donor: O-
Acceptor: AB+

Question 23

What is epistasis?

Answer 23

When 1 gene is dominant to another gene

Question 24

What is a test cross?

Answer 24

A cross between an unknown dominant and homorecessive

Question 25

What is the law of segregation?

Answer 25

Alleles are separated during gamete formation | -anaphase I and II

Question 26

What is the law of independent assortment ?

Answer 26

How one pair separates is independent of how other pairs separated

Question 27

What will F1 be when you have the same homo and homo?

Answer 27

F1= 100% parental genotype and phenotype

Question 28

What will F1 be when you have the homo dominant and homo recessive?

Answer 28

100% hetero genotype | 100% dominant

Question 29

What will F1 be when you have the Hetero and homo dominant/recessive?

Answer 29

50% hetero and 50% homo parent | 50% dominant 50% homo parent

Question 30

What will F1 be when you have the Hetero and hetero?

Answer 30

25%DD 50% Dd 25%dd (1:2:1) | 75% dominant 25% recessive (3:1)

Question 31

What is the rule of multiplication?

Answer 31

Probability of (A+B)= AxB

Question 32

What is the rule of addition?

Answer 32

Probability of (A or B)= A+B - (A+B)

Question 33

What are linked genes?

Answer 33

Genes found close together on the same chromosome. | -closer they are the greater the chance they won't sort independently

Question 34

What is the recombination frequency?

Answer 34

of recombinants/ # of total offspring x 100% - lower the number the closer the are together - higher the number the further they are apart (more recombination

Question 35

According to Hardy weinburg what dont alleles do in a population ?

Answer 35

Alleles do not change frequency within a population | -assume classical dominance

Question 36

What are the considerations of Hardy weinburg ?

Answer 36

1. Random mating 2. No migration 3. No mutation 4. No natural selection 5. Larger population (less genetic drift)

Question 37

How long does it take, after a disturbance, to reestablish equilibrium?

Answer 37

1 generation

Question 38

how do you calculate allele frequency?

Answer 38

p (dom) + q(rec)= 1

Question 39

How do you determine genotype frequency?

Answer 39

pp+ 2pq+ qq= 1