3 Marking scheme: End-of-chapter test
1
a
b
c
2
3
a
b
c
d
e
f
4
5
Events
Stage
Chromosomes line up across the equator of the spindle,
attached to the spindle by their centromeres.
metaphase
[1]
Chromosomes uncoil and elongate. Spindle breaks down
and the nuclear membrane re-forms.
telophase
[1]
Chromosomes shorten and thicken by coiling. Nuclear
membrane breaks down and spindle forms.
prophase
[1]
Chromatids separate and move to opposite poles of the
cell.
anaphase
[1]
Metaphase
A = centromere; B = chromosome; C = spindle; D = centriole.
x = 47 mm = 47 000 µm
47 000
diameter of cell =
(or other correct calculation)
2200
= 21 µm
Asexual reproduction means the production of new individuals of a species from one
parent organism; any suitable example such as binary fission in Amoeba, Hydra budding,
vegetative propagation in plants etc.
Interphase
Cells from meiosis are haploid or have half the number of chromosomes;
cells from meiosis are genetically different both from those produced by mitosis
and from each other.
Cells are smooth/flat; cells fit tightly together; low-friction surface; so fluid/blood can
move easily.
a
b
c
6
Chromosomes are in matching pairs in (most) cells; one member of each pair comes
from the mother and one from the father; in humans there are 23 pairs.
[max. 2]
One pair (of the 23) are the sex chromosomes; they determine the sex of the individual;
females have two X chromosomes and males have an X and a Y chromosome.
[max. 2]
Autosomes are all the other chromosomes apart from the sex chromosomes.
[1]
a
b
[1]
[4]
[1]
[2]
[1]
[1]
[1]
[max. 3]
Cells in a blastocyst/embryo; that are unspecialised/undifferentiated cells; that can divide;
to form different kinds of specialised cells.
[max. 3]
Able to form/differentiate into any kind of cell.
[1]
Blastocyst stem cells are totipotent; adult stem cells can only form limited types of cell.
[2]
Meristems are regions where cells are able to divide or undergo mitosis;
[1]
Examples: root tip; shoot tip; cambium.
[max. 2]
i Lignified cell walls for support; pits for lateral movement of water;
form continuous tubes for movement of water (and minerals); no cytoplasm
(or empty), for water movement.
[max. 3]
ii Few organelles, for transport (of sugars); sieve plates (or pores) in end walls allow
transport through tubes.
[max. 2]
COAS Biology 1 Teacher Resources
Original material © Cambridge University Press 2008
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