Grade 9 Science page 165
B. Budding - c. hydra
C. Fragmentation - d. an animal that grows from a piece that has
separated from the parent.
E. Spore - e. a reproductive cell taht may be able to
survive extreme conditions.
5. Organisms
that reproduce asexually often produce large numbers of offspring to
out-compete other organisms for nutrients and water. In addition, large colonies may survive when
environmental conditions are altered or the number of predators changes.
Grade 9 Science page 166-167
1. Cell
division is necessary for unicellular organisms so that these organisms can
reproduce in great numbers.
2.
Cell division is necessary in
multicellular organisms for growth and repair and to replace worn-out cells.
5. If
the cell is unable to make the proteins to form spindle fibres, mitosis could
not occur successfully since the chromosomes would not be able to attach. The result would be that the chromosomes
would not be equally distributed between cells.
10. The major disadvantage of asexual reproduction is that there is
very little variation so all the offspring are identical. If conditions change, all of the individuals
could die.
15. The
nuclear membrane must disintegrate during prophase so that the chromosomes are
free to move to opposite ends of the cell later.
16. A. These cells are plant
cells.
B. There appears to be a
cell wall and the cells remain side-by-side after cell division.
C.
C - A - D - B
D. Diagram C shows prophase where the chromosomes become
visible.
Diagram A shows metaphase where the double-stranded chromosomes are lined up in a single file
at the equator.
Diagram D shows anaphase where the two strands of the
double stranded chromosome move to
opposite poles.
Diagram B shows telophase where the nuclear membrane
forms around the sets of chromosomes.
