AHHHHH Flashcards
1
Q
A,B,C,D,E,F
A
A - Gap Phase 1 B - M phase C - S phase D - Gap phase 0 E - Gap Phase 0 F - GAP PHASE 2
2
Q
A,B,C,D,E
A
A 144 B 72 C 144 D 144 E 72
3
Q
Why Is it mitosis
A
- mitosis - each of the cells are haploid so only contain one set of chromosomes, during sexual reproduction one set of chromosomes is needed from the paternal and maternal side to create a cell that has the normal number of chromosomes which can divide by mitosis normally, therefore to get one set of cells the bee needs to undergo mitosis to produce an identical copy to the haploid body cells that it already has
4
Q
Why does sexual reproduction involve meiosis
A
- meiosis produces gametes which are haploid cells, this has to happen for sexual reproduction to occur so when two gamete nuclei fuse during fertilisation a diploid zygote is produced, and normal chromosome number is maintained
- mitosis cannot make gametes as gametes only contain half chromosome, mitosis would produce a cell that is identical and not genetically varied
5
Q
How does meiosis produce genetic variation in the gametes produced
A
- in prophase 1 chromatin condenses to form chromosomes
- crossing over of non sister chromatids shuffles alleles and exchanges DNA
- independent assortment of chromosomes in anaphase 1 leads to random distribution of maternal and paternal chromosomes
- independent assortment in anaphase 2 leads to further random distribution:: of genetic material
- haploid gametes are produced which undergo random fusion with gametes derived from another organism of the same species