4.3 - meiosis

Question 1

gamete

Answer 1

sex cell (sperm or egg)

Question 2

sperm is produced

Answer 2

in the testes

Question 3

eggs (ova/ovum) are produced

Answer 3

in the ovaries

Question 4

are gametes haploid or diploid

Answer 4

haploid

Question 5

fertilization

Answer 5

the fusion of a sperm and egg to form a zygote which divides and multiplies to make an embryo

Question 6

zygote

Answer 6

diploid fertilized egg

Question 7

meiosis

Answer 7

the process of making gametes in sexually reproducing organisms

Question 8

3 main steps to meiosis

Answer 8

interphase
meiosis |
meiosis ||

Question 9

interphase (meiosis)

Answer 9

DNA replicates and the cell prepares for meiosis
occurs in a spermatocyte and oocyte which are both diploid cells

Question 10

spermatocyte

Answer 10

male diploid sex cell

Question 11

oocyte

Answer 11

female diploid sex cell

Question 12

homologous chromosomes desc

Answer 12

pair of chromosomes similar in shape and size
homologous pairs carry genes controlling the same inherited traits
(humans have 23 pairs of homologous chromosomes, 22 autosome pairs and 1 sex chromosome pair)

Question 13

homologous pairs are also called

Answer 13

tetrads because a homologous chromosome pair consists of 4 chromatids

Question 14

meosis 1- prophase desc

Answer 14

synapsis- chromosomes pair up beside each other
crossing over- genetic information is mixed
nuclear membrane disappears and spindle fibres form

Question 15

what is crossing over?

Answer 15

while synapsis is when a paternal and maternal chromosome pair to form a tetrad, chromosomes SEGMENTS are exchanged between two non-sister chromatids to mix up the genetic information

Question 16

meiosis 1 - metaphase 1

Answer 16

homologous chromosomes line up in the middle of the cell in random assortment
spindle fibres move chromosomes to centre

Question 17

what is random assortment?

Answer 17

homologous pairs of chromosomes will line up in the middle of the cell. The maternal and paternal arrangement is randomized, allowing for variation in the gametes

Question 18

meiosis 1- anaphase 1

Answer 18

spindle fibres pull toe homologous chromosomes to opposite poles

Question 19

meiosis 1- telophase 1

Answer 19

chromosomes reach the poles
spindle fibres dissolve
nuclear membrane forms

Question 20

meiosis 2- prophase 2

Answer 20

nuclear membrane disappears
spindle fibres form in each new cell

Question 21

meiosis 2- metaphase 2

Answer 21

chromosomes line up in the middle

Question 22

meiosis 2- anaphase 2

Answer 22

centromeres separate and chromatids are pulled to opposite poles

Question 23

meiosis 2- telophase 2

Answer 23

chromatids reach the poles
spindle fibres dissolve
FOUR new nuclear membranes form

Question 24

gametogenesis is composed of

Answer 24

spermatogenesis
oogenesis

Question 25

spermatogenesis

Answer 25

production of sperm cells in the testes (4 viable sperm cells are produced)

Question 26

oogenesis

Answer 26

production of egg cells in the ovaries (1 viable egg cell is produced and is much larger than a sperm cell)

Question 27

karyotype

Answer 27

a photograph of stained chromosomes sorted and arranged by size and type

Question 28

each homologous set in a karyotype is made of

Answer 28

2 homologues

Question 29

sex determination in some animals

Answer 29

humans (xx= female xy= male) birds (zw=female zz=male) reptiles (temperature warm egg= female cold egg = male) fish (males become female w/ age) insects (fertilization fertilized = female etc.)