Download Cell Division Homework w.answers

Name _________________________________________
Period ______
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Cell Division Introduction
1. Distinguish between asexual reproduction and sexual reproduction.
Asexual Reproduction – one parent, genetically identical offspring
Sexual Reproduction – usually two parents, gametes formed, genetically different offspring
2. Distinguish between somatic cells and germ cells (gametes).
Somatic cells – also called “body” cells have a diploid or full set of chromosomes. These cells
build tissues that function as organs.
Germ cells (gametes) – called sex cells – sperm and egg. Specialized cells with ½ total
chromosome # used for reproduction.
3. Identify three differences between mitosis and meiosis.
1.
2.
3.
4.
Mitosis produces 2 cells/Meiosis produces 4 cells
Cells from mitosis are genetically identical, meiosis makes genetically different cells.
Mitosis makes diploid cells. Meiosis makes haploid cells
Mitosis = 1 division Meiosis = 2 division (meiosis I and II)
4. Distinguish between diploid and haploid cells and give an example of each.
Diploid – full set of chromosome (1 chromosome from each parent)
Human 2n = 46
Haploid – Half set of chromosomes
Human n = 23
5. Draw a replicated chromosome and label the sister chromatids and centromere.
Sister chromatids are exact copies of each other (same genes)
Centromeres hold sisters together
The chromosome to the right has been replicated
Kinetochore is a protein disk where microtubules attach.
6. Describe the events of the cell cycle:
Cell is growing, producing organelles, copying DNA (S phase), and
preparing for cell division (G1, S, G2)
Interphase
M phase involves the cell dividing, going through PMAT to produce 2
daughter cells. Prophase, Metaphase, Anaphase, Telophase
Mitosis
Cytokinesis
-
Division of cytoplasm in Telophase
Cleavage furrow forms
Actin and myosin filaments constrict membrane and cause it to
pinch inward, eventually separating the cells.
7. Distinguish between autosomes and sex chromosomes.
Autosomes – chromosome in pairs 1-22 (not sex chromosome X or Y)
Sex Chromosomes – XX = female
XY = male
23 pair of chromosomes in humans
8. Define the following terms:
Karyotype – a digital photograph of chromosomes taken during metaphase that give
an indication of possible chromosome abnormalities.
Homologous Chromosomes – chromosomes inherited from mother and father that
have the same genes at the same locations
Zygote – A fertilize egg (2n) that will divide and grow via mitosis into an organism.
Fertilization- the union of sex cells (sperm and egg). A zygote is formed when
fertilization occurs (zygote is diploid)
Crossing Over - Exchange of chromosome pieces between chromatids of
homologous pairs – occurs during prophase of meiosis I