CHAPTER 11-4
MEIOSIS
Below is a diagram showing the process of asexual reproduction in a Hydra.
1.What is the advantage of asexual
reproduction over sexual reproduction?
Below is a diagram representing sexual reproduction in humans.
2. What is the difference between asexual and sexual
reproduction?
3. What is the advantages of sexual reproduction over
asexual reproduction?
Below is an electron microscope picture of human sex cells.
4. Sex cells are also known as _______________ (hint: starts
with a “g”).
5. The animal male sex cell is known as a ______________.
6. The animal female sex cell is known as an _______________.
7. What is the process called in which sex cells are produced?
Below is a picture of the human karyotype (all the chromosomes in the nucleus) in a body cell.
This is the karyotype of a human somatic cell (body cell). Each chromosome has an identical
chromosome that pairs with it. This pair of identical chromosomes is known as “homologous
chromosomes”. One chromosome in the pair comes from the male parent and the other one comes
from the female parent.
8. How many chromosomes does a human have in their somatic cells (hint: count all of the
chromosomes in the karyotype)?
9. How many homologous pairs does a human have in their somatic cells (hint: count the pairs of
chromosomes)?
10. A cell that contains both sets of homologous chromosomes is said to be __________________,
which means “two sets”.
11. What symbol represents the diploid number of chromosomes in a cell?
12. Is the karyotype shown in the above diagram of a male or female human? How do you know?
Below is another picture of human sex cells (gametes).
13. How many chromosomes are in each one of these cells?
14. The term used to describe these cells is _______________, which means
“one set”.
15. What symbol represents the haploid number of chromosomes in a cell?
Below is a diagram showing Meiosis compared to Mitosis.
Below is a diagram comparing the process of meiosis to mitosis.
16. Mitosis begins with a
diploid cell and finishes with
_____ cells that are each
____________ in their
chromosome number.
17. Meiosis begins with a
diploid cell and finishes with
_________ cells that are each
____________ in their
chromosome number.
18. Mitosis has one division
whereas meiosis has
__________ divisions.
19. If the diagram of meiosis was representing a human male, then each of the 4 new cells would be
_____________. If a female, then they would be called _________________.
20. Meiosis is a process of____________________ division in which the number of chromosomes per
cell is cut in ________________ through the separation of __________________ chromosomes in a
diploid cell.
Below is a detailed diagram of Meiosis I (PMAT I). This cell has completed the S phase of Interphase.
21. If this is a human cell,
how many chromosomes
would it have in Prophase
I?
22. What happens to the
homologous sister
chromatids during
Prophase I that is
different than the events
of Prophase in mitosis?
23. The group of 4
chromatids is referred to
as a ___________.
24. In Metaphase I of meiosis, what structures line-up at the equator (metaphase plate)?
25. In Anaphase I of meiosis, the ______________ divide and the sister _____________ move in
opposite directions.
26. If this was a human cell, how many sister chromatids would be moving north? How many
chromosomes would be moving south?
Below is a diagram of Meiosis II (PMAT II). This cell has completed Anaphase I of Meiosis I.
27. What occurs following
Telophase I?
28. What does not occur to
the DNA or chromosomes
following Meiosis I that
ensures haploid gametes?
29. What aligns at the
equator during Metaphase
II?
30. During Anaphase II, if this was a human cell, how many chromosomes would be heading west (to the
left)?
31. At the conclusion of Meiosis II, there are _____________ gametes each with a __________ number
of chromosomes.
Below is a diagram representing the process of crossing-over during meiosis.
32. When does “crossing-over” occur during meiosis?
33. What is exchanged during crossing-over?
34. Is crossing-over a form of genetic variation, and hence the
purpose of sexual reproduction?
Below is a diagram of the sexual reproductive cycle in humans.
32. What organ creates the male
gametes? Female gametes?
33. When the sperm meets the egg
(ovum), what process occurs?
34. Following fertilization, the cell is
now called a _________________.
35. Fertilization reestablishes the
________________ chromosome
number.
36. The zygote will continue to divide
by the process of
___________________ for 9.5 months
until birth (and thereafter).
37. Following birth, when will a human
start sending cells through meiosis?