Download Cell Division Notes - Renton School District

Cell Division Notes
Biology
Vocabulary
• Mitosis: process of normal cell division,
results in 2 identical cells
• Meiosis: cell division involving gametes
where number of chromosomes are cut in
half
• Homologous: chromosome from each
parent match (the same)
• Diploid: (double) two complete sets of
inherited chromosomes
Vocabulary
• Haploid: single set of chromosomes
(half)
• Zygote: fertilized egg
• Gamete: specialized cells involved in
sexual reproduction cells (sex cells,
sperm and ova)
• DNA: deoxyribonucleic acid = genetic
information
Do Now
2/28/17
Write the answers to the following questions
on your paper:
• Why do you think cells need to divide?
• What is found in the nucleus?
• What is DNA?
Why do cells divide?
• Cells need to divide in order to:
• Create more cells for the organisms to
grow
• Replace old cells
• Create reproductive cells
Types of Cell Division
• Cell Cycle
• Includes Mitosis
• Used for creating more cells for organism growth and
repair or replacement
• Makes two identical copies
• Meiosis
• Used for creating reproductive cells
• Makes four cells with half the genetic information in
each
What is a chromosome?
• Chromosome: a
structure made of
coiled DNA
• Becomes visible
during cell division
• Made up of two sister
chromatids held by a
centromere
Cell Cycle Drawing, draw
and label the phases
End Result of Cell Cycle
• Cell Cycle ends in
two identical cells
called daughter cells
Meiosis
Why meiosis?
• Chromosome number must be split in two
• Cells are diploid (two sets of chromosomes)
• Gametes, reproductive cells (sperm and eggs) are haploid
(only one set of chromosomes)
How is it different from the cell cycle (mitosis)?
• Requires two cell divisions
• Each cell contain ½ of the chromosomes (genetic material)
Homologous Chromosomes
What is a homologous
chromosome?
• The pair of
chromosomes from each
parent
• Ex: Homologous
chromosome 1: 1 from
Mom and 1 from Dad
Meiosis
Parts of Meiosis
• Meiosis 1: homologous chromosomes separate
• Meiosis 2: sister chromatids separate, four haploid cells are
formed
Meiosis
Compare and Contrast
Mitosis and Meiosis
On your own paper, answer the
following:
1. How are the two processes
different?
2. How are the two processes
the same?
3. How are the end results the
same?
4. How are the end results
different?
5. What types of cells do each
process?