11 Cell cycle and division I
2nd Term WS 12
1 (a) P: metaphase 1m
Q: prophase 1m
R: anaphase 1m
(b) The sister chromatids of each
chromosome separate 1m
and move to the opposite poles of the cell. 1m
(c) New nuclear membranes will form
around each group of chromosomes.
/ The chromosomes will uncoil to become
chromatin again. 1m
2 (a) nuclear membrane 1m
(b) chromatids 1m
(c) metaphase 1m
(d) anaphase 1m
(e) telophase 1m
3 (a) (i) X: cell growth / interphase 1m
Y: mitotic cell division 1m
(ii) DNA replication
/ Protein synthesis
/ Organelle
synthesis
/ Cell growth to maximum size (any
3) 1m x 3
(b) (i)
(ii) (1) 6 1m
(2) 6 1m
(iii) Metaphase 1m
Chromosomes line up in the middle
of the cell. 1m
4 (a) DNA and
proteins 1m
(b) Meiotic cell division 1m
The chromosomal material in a daughter cell
is half of that in a parent cell. 1m
(c) P: DNA replication 1m
Q: Separation of the cell into two
/ Cytoplasmic
division after the homologous chromosomes separate 1m
R: Separation of the two cells into four
/ Cytoplasmic
division after the sister chromatids separate 1m
(d) Meiotic cell division produces
haploid gametes. This ensures the diploid number of chromosomes can be restored
when two gametes fuse at fertilization. 1m
Meiotic cell division produces genetic
variations in gametes by independent
assortment of chromosomes and crossing over. 1m
沒有留言:
張貼留言