answer the following question in a complete sentence. a carrot cell contains 18 chromosomes. which...
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Answer the following question in a complete sentence.
A carrot cell contains 18 chromosomes. Which of the diagrams at the right illustrates the correct number of chromosomes in new cells produced by mitosis? How do you know?
Objectives:1)To describe the process of meiosis
2)To compare meiosis to mitosis
Meiosis
Mitosis ReviewThe process of cell divisionOccurs in somatic cells which are all the
cells in your body except egg and sperm cells
2N Diploid meaning that it has two of each chromosomeThese two chromosomes are identical in
mitosis
I. MeiosisA. Process of making sex cells called gametes
1. Male gametes are sperm2. Female gametes are eggs
B. Sex cells have half the number of chromosomes as other cells
1. N (haploid)
C. When sperm fertilizes egg zygote1. 2N (diploid) – it has 2 of each chromosome,
1 from mom, 1 from dad
II. Meiosis occurs in 2 divisionsA. Interphase I - Before meiosis, cells in testes/ovaries
copy DNA
B. Meiosis I1. Prophase I - Chromosomes with same type of genetic
information (homologous chromosomes) match up a. these chromosomes may “swap” genes
2. Metaphase I - Homologous pairs line up in middle of cell RANDOMLYRANDOMLY
3. Anaphase I - Pairs split up4. Telophase I – Cell membrane begins to pinch in and
results in 2 daughter cells are different from each other & parent cell
C. Between meiosis I and meiosis II, DNA does not copy again
D. Meiosis II is like mitosis1. Prophase II – new spindle fibers form
around the chromosomes2. Metaphase II - Chromosomes line up
in center of cell3. Anaphase II - Chromosomes split
apart & move into daughter cells4. Telophase II - End result: 4
daughter cells that are each unique
View meiosis
III. How does meiosis compare to mitosis?
A. Mitosis1. Replicate once,
divide once2. 2 daughter
cells are identical to parent cell
B. Meiosis1. Replicate once,
divide twice2. 4 haploid
daughter cells, not identical to parent or each other
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