Download Unit 4 modified portfolio Comparing Mitosis and Meiosis

Unit 4 modified portfolio
Comparing Mitosis and Meiosis (18 points total are possible)
Review the comparison of mitosis and meiosis, below, and use the
information to help you fill in the chart.
Cell Division
Smaller cells are more efficient at transporting materials in/out of the cell, than larger cells.
When cells grow too big, they divide. They also divide for repair (healing)
Before cells can divide, they must copy all of their DNA, first, to ensure the new cells get the correct
number of chromosomes. This process is called DNA replication (copies) and occurs during the “S”
(synthesis) phase.
2 types of cell division:
Mitosis produces diploid cells (2 of each chromosome) and they are exact copies of parent cell. Some
organisms, can reproduced by mitosis. Hydra can form buds, which are genetic clones of the parent but
will eventually become a new hydra.
Meiosis produces haploid cells (1 of each chromosome –half) and they are genetically different than
the parent cell.
4 phases of cell division
Prophase: prepare to divide nucleus dissolves, temporarily to allow chromosomes to move around
(“pro” means before)
Metaphase: chromosomes line up in the middle of the cell (“meta” means middle). While lined up in
the middle, spindle fibers attach to pull sister chromatids apart
Anaphase: chromosomes get pulled apart (with the help of centrioles “cowboys” in animal cells)
Telophase: the nucleus begins to reappear after chromosomes are separated to each new cell
Cytokinesis: the cytoplasm divides. In plants it occurs with a cell plate and in animals cells it occurs with
a cleavage furrow (like a drawstring bag).
Chart is worth 6 points
Mitosis
Define the process
What is the purpose of this type
of division? (growth and repair
or production of gametes)
Where in the body, does it
occur? (ex. all body cells or
reproductive organs)
Type of cell produced? (Ex. an
exact copy or genetically
diverse cells)
Are daughter cells haploid or
diploid? (ex. n or 2n)
Involves crossing over and
recombination of genes? (yes or
no)
Number of divisions? (1x or 2x)
Number of cells produced (2 or
4)
In human cells, the final
chromosome number produced
(23 or 46)
Meiosis
Analysis Questions (2 points each)
1. Crossing over, between non-sister chromatids during meiosis is
significant in heredity. This process most likely leads to an increase in
which of the following?
a. The expression of dominant traits
b. Number of gametes
c. The occurrence of polyploidy
d. Genetic variation
2. Which of these must occur during S phase, of the cell cycle, so that
two daughter cells can be produced during M phase?
a. The DNA must be replicated
b. The chromosomes must be joined
c. The cytoplasm must be separated
d. The cell membrane must be expanded
3. The leaf cells of the white oak (Quercus alba) contain 24
chromosomes. After meiosis is complete, how many chromosomes are
in the new cells?
a. 12
b. 20
c. 24
d. 48
4. A cut on a frog’s foot will repair itself using the process of –
a. Mitosis
b. Meiosis
c. Phagocytosis
d. Pinocytosis