1. Sexual Reproduction and Genetics
Chapter 10
Sexual Reproduction and Genetics

2. Chapter 10.1
Meiosis

3. Chromosomes
Structures that contain the genetic material that is passed from generation to generation of cells.
Homologous Chromosomes – make up a pair.
Human body cells have 46 chromosomes, each parent contributes 23 chromosomes.
23 pairs of chromosomes per cell.
Carry genes that control the same inherited traits.
Genes – segments on the DNA that determine the characteristics and functions of the cell.

4. Haploid vs. Diploid Cells
Gametes – sex cells that have half the number of chromosomes
This is done to maintain the same number of chromosomes from generation to generation.
Haploid (n) Cells – cells with only one set of chromosomes
In humans this would be 23
Diploid (2n) Cells – cells with 2n number of chromosomes
In humans this would be 46
Fertilization – process in which a a haploid gamete combines with another haploid gamete.

6. Sexual v. Asexual Reproduction
Read the section Sexual Reproduction v. Asexual Reproduction on p Compare and contrast these types of reproduction by recreating the table in your notebook.
Sexual Reproduction
Asexual Reproduction

7. Sexual v. Asexual Reproduction
Read the section Sexual Reproduction v. Asexual Reproduction on p Compare and contrast these types of reproduction by recreating the table in your notebook.
Sexual Reproduction
Asexual Reproduction
Two parents
Offspring are genetically different from parents
Genetic variation each generation
Most Plants & Animals
One parent
Offspring are genetically identical to parent
Bacteria (and most protists)

8. Important Vocabulary
Read through Chapter 10.1 and define the following terms in the table below:
Vocabulary
Definition
Gene
Homologous chromosomes
Gamete
Haploid
Fertilization
Diploid
Meiosis
Crossing over

9. Important Vocabulary
Read through Chapter 10.1 and define the following terms in the table below:
Vocabulary
Definition
Gene
DNA segments that control the production of proteins (and traits)
Homologous chromosomes
Paired chromosomes; one chromosome from each parent
Gamete
Sex cell (sperm or egg); contain HALF the number of chromosomes
Haploid (n)
A cell with one set of chromosomes (n)
Fertilization
Process where one haploid gamete joins another haploid gamete
Diploid (2n)
A cell with two sets of chromosomes (one set from each parent)
Meiosis
Cell division that reduces the number of chromosomes
Crossing over
Process where chromosome segments are exchanged between homologous pairs

10. Meiosis Process in which gametes are formed.
Type of cell division that reduces the number of chromosomes; called a reduction division.
Reduces chromosome number by the separation of homologous chromosomes.
2n n
Occurs in the reproductive structures of organisms that reproduce sexually.
Involves two consecutive cell divisions called meiosis I and meiosis II

16. Animations http://www.biostudio.com/d_%20Meiosis.htm
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hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/ /120074/bio16.swf::Unique Features of Meiosis

17. Meiosis I

21. Interphase and Meiosis I

22. Meiosis II

25. Crossing over
During prophase, the homologous chromosomes exchange segments of DNA

30. Mitosis and Meiosis Mitosis Meiosis One division
Two divisions (meiosis I and II)
DNA replication during interphase
Homologous chromosomes do NOT pair up
Homologous chromosomes pair up
Daughter cells are genetically identical
Daughter cells are not genetically identical (crossing over occurs)
Mitosis occurs in body cells only
Meiosis occurs in reproductive cells
Mitosis involved in growth and repair
Meiosis involved in producing gametes and increasing genetic variation