Question 1:
Figure I shows cells R and S undergoing cell division.
(a)(i) Name the structures labelled K and M.
(a)(ii) State the phase of division of cells R and S.
(b) Cell R undergoes three consecutive divisions.
(c)(i) Cell S undergoes the first nuclear division and produces two cells.
Complete the diagram to show the chromosomes in one of the cells produced.
(c)(ii) Name one organ where cell S is found.
(c)(iii) The number of chromosomes I a somatic cell of a fly is 12.
State the number of chromosomes in a daughter cell produced at the end of the type of cell division as shown by cell S.
(d) Cancer is a disease which causes uncontrolled growth of tissues.
Radiotherapy is a method to treat cancer by using radiation.
Explain how this treatment stops the growth of cancer cells.
(e) An oil palm planter wants to produce a large number of oil palms in a short time.
State the best technique to be used by the planter and one problem to be considered in using the technique.
Answer:
(a)(i)
K: Chromatid
M: Spindle fibre
(a)(ii)
Cell R: Metaphase
Cell S: Metaphase I
(b)
8 daughter cells
(c)(i)
(c)(ii)
1. Testis
2. Ovary
(c)(iii)
6 chromosomes
(d)
Radioactive rays destroy the cells, so the rate of mitosis is controlled.
(e)
– Cloning / culture tissue
– All the clones are easily attacked by diseases because all the clones have the same resistance towards diseases.
Figure I shows cells R and S undergoing cell division.
(a)(i) Name the structures labelled K and M.
(a)(ii) State the phase of division of cells R and S.
(b) Cell R undergoes three consecutive divisions.
(c)(i) Cell S undergoes the first nuclear division and produces two cells.
Complete the diagram to show the chromosomes in one of the cells produced.
(c)(ii) Name one organ where cell S is found.
(c)(iii) The number of chromosomes I a somatic cell of a fly is 12.
State the number of chromosomes in a daughter cell produced at the end of the type of cell division as shown by cell S.
(d) Cancer is a disease which causes uncontrolled growth of tissues.
Radiotherapy is a method to treat cancer by using radiation.
Explain how this treatment stops the growth of cancer cells.
(e) An oil palm planter wants to produce a large number of oil palms in a short time.
State the best technique to be used by the planter and one problem to be considered in using the technique.
Answer:
(a)(i)
K: Chromatid
M: Spindle fibre
(a)(ii)
Cell R: Metaphase
Cell S: Metaphase I
(b)
8 daughter cells
(c)(i)
(c)(ii)
1. Testis
2. Ovary
(c)(iii)
6 chromosomes
(d)
Radioactive rays destroy the cells, so the rate of mitosis is controlled.
(e)
– Cloning / culture tissue
– All the clones are easily attacked by diseases because all the clones have the same resistance towards diseases.