Download For example eye color (One gene from each parent).

Chapter 11-4
Cell Division
A thread-like structure containing
genetic information.
b.
Tightly coiled DNA strands
c.
Homologous
• Pairs of chromosomes that
contain information for the same
biological features.
For example eye color (One gene
from each parent).
d.
Tetrad
• The structure made when the
homologous chromosomes join.
a.
Cell division resulting in the number of
chromosomes in a cell being divided in half,
through the separation of homologous
chromosomes.
Diploid cells divide to produce haploid cells.
a.
b.
•
•
c.
Haploid – Cells that contain “half” the genetic
information. One set of chromosomes. (n)
Diploid – Cells that contain both sets of homologous
chromosomes. (2n)
Only occurs in reproductive cells.
Cell division process similar to mitosis.
d.
•
Occurs during the “M Phase” of the cell
cycle.
•
Similar phases:
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis
•
•
•
•
•
Unlike mitosis, MEIOSIS involves 2 divisions:
Meiosis I and Meiosis II.
a.
•
Produces 4 cells instead of 2.
•
Cells produced contain half the genetic
information as the parent cell.
b.
Crossing Over: During prophase 1 the
homologous chromosomes pair up and
form tetrads, they also exchange genetic
information.
Gametes: Sex cells that contain half the
genetic information (haploid) produced
during meiosis.
a.
•
•
b.
c.
In males = sperm cells
In females = egg cells (ova)
Spermatogenesis: The process of making
sperm cells. Occurs in the male reproductive
organs, testes.
Oogenesis: The process of making egg cells
(ova). Occurs in the female reproductive
organs, ovaries.
d.
Fertilization: The process of male and
female haploid gametes (n) fusing to form a
diploid zygote (2n).