Meiosis 1

Question 1

What is a homologous chromosome?

Answer 1

2 chromosomes in a pair that are relative in space

Question 2

What is a haploid?

Answer 2

A set of unpaired chromosomes

Question 3

What is a diploid?

Answer 3

2 paired together chromosomes

Question 4

What is a ploidy?

Answer 4

The number of sets of chromosomes in a cell or organism

Question 5

Interphase has how many Chromosomes and how many chromatids

Answer 5

It has 46 chromosomes and 92 chromatids

Question 6

What happens in prophase 1?

Answer 6

crossing over occurs (synapsis), chasm where DNA is crossed over, every pair of homologous chromosomes crosses over at least once, spindle forms, nuclei comes apart

Question 7

Chromosomes are counted by what?

Answer 7

Centromeres (not the number of chromatids)

Question 8

Heterozygous

Answer 8

2 different alleles for a given gene

Question 9

What is a phenotype?

Answer 9

They are the observable traits expressed by an organism

Question 10

What is recombination?

Answer 10

Crossing over or transferring genetic information

Question 11

What is the law of segregation?

Answer 11

when an organism makes gametes each gamete receives only one gene copy

Question 12

What is linkage?

Answer 12

when genes are further apart they are more likely to cross over with another chromosome and the closer they are the less likely they are to cross over.

Question 13

What is continuous variation?

Answer 13

the action of many genes to determine a characteristic like human height

Question 14

What is a trait?

Answer 14

the physical appearance of a heritable characteristic

Question 15

product rule

Answer 15

PaxPb

Question 16

sum rule

Answer 16

Pa+Pb

Question 17

What is mode of inheritance?

Answer 17

to predict the probability of a trait or disease to appear in offspring

Question 18

What type of trait can skip a generation?

Answer 18

a recessive trait

Question 19

What is an autosome?

Answer 19

inherited patterns among non-sex chromosomes

Question 20

What is hemizygous?

Answer 20

only one allele (x-linked in males)

Question 21

What is a X-linked gene?

Answer 21

a gene that present on the X chromosome and not the Y (opposite for Y-linked gene)

Question 22

What is incomplete dominance?

Answer 22

Both alleles of a gene are partially expressed, results in an intermediate or a different phenotype

Question 23

What is codominance?

Answer 23

Both alleles for the same characteristic are simultaneously expressed.

Question 24

metaphase 1

Answer 24

chromosomes line up at the metaphase plate

Question 25

anaphase 1

Answer 25

homologous chromosomes get pulled apart (each complete with both sister chromatids)

Question 26

telophase 1

Answer 26

nuclear membrane reforms and cytokinesis occurs, we get 2 haploid daughter cells

Question 27

prophase 2

Answer 27

spindle apparatus forms

Question 28

metaphase 2

Answer 28

chromosomes align at the meta phase plate (chromatids aren’t identical due to crossing over) spindle attaches to kinetecores

Question 29

anaphase 2

Answer 29

sister chromatids are pulled apart

Question 30

telophase 2

Answer 30

nuclear membrane reforms and cytokinesis occurs (4 haploid cells 23 unduplicated chromosomes each

Question 31

Prometaphase 1

Answer 31

Homologous chromosomes are attached to spindle microtubules at the fused kinetochore shared by sister chromatids

Question 32

Prometaphase 2

Answer 32

the nuclear envelope disappears and the spindle fibers engage the individual kinetochores on the sister chromatids

Question 33

Formula for recombination frequency

Answer 33

[(Recombinants)/(total offspring)]x100

Question 34

Gain of function mutation

Answer 34

results in a more active protein (dominant)

Question 35

Loss of function mutation

Answer 35

results in a inactive or less active protein (recessive)