cell biology and genetics 3 - neil

Question 1

what is the cell cycle made up of?

Answer 1

2 major phases

Question 2

what are the 2 major phases in cell division?

Answer 2

I & M

Question 3

I phase-

Answer 3

Cell grows, DNA is synthesised, and organelles replicate

Question 5

m phase

Answer 5

Nuclear division (Mitosis) followed by Cytoplasmic division (Cytokinesis

Question 6

how many chrosomes in the g1 phase

Answer 6

2n diploid

Question 7

how many chrosomes in the s phase

Answer 7

2n- 4n (tetraploid0

Question 8

how many chrosomes in the g2 phase

Answer 8

4n (tetraploid)

Question 9

how many chromsomes in the M phase

Answer 9

4n to 2n (diploid)

Question 10

where does meiosis occurs>

Answer 10

in the gonads

Question 11

what does gonad produce

Answer 11

produce reproductive cells as gametes

Question 12

what type of cells are the gametes

Answer 12

they are diploid and only carry one copy of each type of chromsome

Question 13

what happens to the chrosmomes in meiosis?

Answer 13

Chromosomes exchange DNA by Genetic Recombination before being shared out in new combinations in single chromosomes sets (Haploid).

Question 14

what does genetic recombination result in>

Answer 14

results in the formation of New combinations of genes

Question 15

summarize synapsis in metphase one

Answer 15

occurs during Prophase I
process where homologous chromosomescome together and align very closely along their lengths

Question 16

what structure causes the homologous chrososommes come together in metaphase one

Answer 16

synaptonemal complex.

Question 17

what is the purpose of metphase one

Answer 17

crucial for the process of crossing over

Question 18

where does homogloos chrosmsoems join to form? (1)

Answer 18

they join together in pairs to form synaptonemal complex

Question 19

how is each pair of chromatids connecteced? (2)

Answer 19

axial protein

Question 20

how are the 2 homolgous chrosmsomes held together? (3)

Answer 20

central element proteins

Question 21

recombination nodule (4)

Answer 21

RN forms that contains enzymes for cutting and splicing DNA. chromsomes are cut and joined crosswire at points called chiamata where they seperate

Question 22

why is exchange of gentic material dangerous

Answer 22

leads to deletions and duplications

Question 23

what is the results of crossing over?

Answer 23

each of chromatid ends up in a seperate gamete
2 of them have paretnal genotypes and 2 the recombinat genotypes

Question 24

where does radnom assoertment take place

Answer 24

Random, independent assortment during Metaphase I