meiosis

Question 1

diploid cell

Answer 1

cell that has two full sets of chromosomes

Question 2

haploid nuclei

Answer 2

nuclei with one set of chromosomes within special gamete cell

Question 3

zygote

Answer 3

when two haploid nuclei fuse together to form new diploid cell called zygote

Question 4

polyploidy

Answer 4

having more than two sets of chromosomes per nuclei

Question 5

where are gametes formed

Answer 5

in special sex organs

Question 6

gonads

Answer 6

sex organs in animals

Question 7

anthers

Answer 7

male sex organs in plants

Question 8

female sex organs in plants

Answer 8

ovaries

Question 9

where are the male gametes formed in

Answer 9

the pollen made in anthers

Question 10

where are female gametes made in plants

Answer 10

ovules contained in ovaries

Question 11

male sex organs in animals

Answer 11

testes

Question 12

what gametes do testes produce

Answer 12

spermatozoa

Question 13

female gonads

Answer 13

ovaries that produce female gametes ova or eggs

Question 14

male gametes description

Answer 14

many
mini
motile

Question 15

female gamete description

Answer 15

few
fat
fixed

Question 16

what does meiosis form in male flowering cells

Answer 16

microspores

Question 17

what does meiosis form in female flowering cells

Answer 17

megaspores

Question 18

what does meiosis give rise to

Answer 18

four haploid daughter cells

Question 19

homologous pairs

Answer 19

two chromosomes of each pair stay close together

Question 20

crossing over

Answer 20

where chromatids break and recombine

Question 21

prophase 1

Answer 21

each chromosomes condensed with 2 chromatids
-homologous pairs with each other
-crossing over occurs

Question 22

metaphase 1

Answer 22

spindle forms
-pairs of chromosomes line up on metaphase plate

Question 23

anaphase 1

Answer 23

centromeres dont divide
-one chromosome from homologous pair moves to each end of cell
-chromosomes number in each cell half

Question 24

telophase 1

Answer 24

nuclear membrane divides
-cells begin to divide
-continues to full cytokenesis
-during this interphase no further replication of dna

Question 25

prophase 2

Answer 25

new spindles formed

Question 26

metaphase 2

Answer 26

chromosomes made up of pair of chromatids -line up on metaphase plate

Question 27

anaphase 2

Answer 27

centromeres divide -chromatids move to opposite ends of cell

Question 28

telophase 2

Answer 28

nuclear envelope reforms -chromosomes return to interphase -cytokenesis occurs -gives four daughter cells -each has half number of chromosomes of original diploid cell

Question 29

2 ways variation occurs in meiosis

Answer 29

independent assortment crossing over

Question 30

whats independent assortment

Answer 30

chromosomes that came from organisms 2 parents distributed into gametes and into offspring at random

Question 31

whats crossing over

Answer 31

when large multi enzyme complexes cut and join bits of maternal and paternal chromatids together

Question 32

chiasmata

Answer 32

points where chromatids break

Question 33

importance of crossing over

Answer 33

-added genetic variation errors lead to mutations to have more genetic variation

Question 34

chromosome mutations

Answer 34

parts of chromosomes break off and become reattached in wrong place

Question 35

translocation

Answer 35

when a piece from one pair of homlogous chromosomes breaks off and reattaches to different pair of chromosomes

Question 36

unbalanced translocations

Answer 36

when one chromosome gains an extra one and can change phenotype of organism

Question 37

effect of translocation mutations

Answer 37

lead to core binding factor acute myeloid leukaemia

Question 38

non disjunction mutations

Answer 38

members of one homologous chromosomes fails to seperate during anaphase 2 one of gametes had two copies of chromosome and other has none

Question 39

effects of non disjunction mutations

Answer 39

monosomy polysomy

Question 40

monosmy

Answer 40

only one member of homologous pair present in normal gamete

Question 41

polysomy

Answer 41

three or more rather than 2 of chromosome pair

Question 42

aneuploidy

Answer 42

when cell lacks whole chromosome or has more than two chromosomes

Question 43

whats down syndrome an example of

Answer 43

non disjunction polysomy

Question 44

babies with down syndrome have what

Answer 44

trisomy of chromosome 21

Question 45

what happens if there is non disjunction of chromosome 21 in ovum or sperm

Answer 45

one of gametes will have two copies of chromosome

Question 46

problems of down syndrome

Answer 46

heat disorders lack of muscle tone visual problems

Question 47

mutagens

Answer 47

ionising radiation- increases mutation rate -chemicals age ova vulnerable

Question 48

whats turners syndrome an example of

Answer 48

non disjunction monosomy

Question 49

what happens if theres non disjunction of sperm cells

Answer 49

ova fertilised with no sex cells from sperm embryo monosomy only x chromosome

Question 50

genotype of egg cell with monosomy

Answer 50

XO that results in turners syndrome

Question 51

effect female of turners syndrome

Answer 51

is female but doesnt go through puberty without being given extra sex hormones

Question 52

kleinfelters syndrome

Answer 52

when male chromosome has XY and results in cell with XXY genotype

Question 53

effect of kleinfelters syndrome

Answer 53

develop breast tissue little facial hair may be infertile less muscle development