1. Sexual Reproduction

2. Usually occurs in plants, animals, and most multicellular organisms
Sexual Reproduction
Offspring are formed when genetic information is passed from more than one parent and shares the characteristics of both parents– a male and female; the offspring is unique
The female sex cell is the egg (ova) and the male sex cell is the sperm
Usually occurs in plants, animals, and most multicellular organisms

3. What do you remember about mitosis?
Sexual Reproduction
What do you remember about mitosis?
Mitosis – asexual reproduction of cells; two exact copies of the parent cell
Contain 46 chromosomes
Also known as diploid cells (diploid = duplicate)
Examples include skin, muscle, and blood cells

4. Sexual Reproduction
Meiosis – sexual reproduction of cells; contains only half the number of chromosomes
Contain 23 chromosomes each; when joined there is a total of 46 chromosomes
Chromosomes that carry the same set of genes are homologous
Also known as haploid cells (haploid = half)
Examples include sperm and egg/ova (gametes)
Chromosomes are copied once, but the nucleus divides twice!

5. Page 114

7. Create a T-chart in your comp book.
diploid
haploid
Two sets of chromosomes
One set of chromosomes
Mitosis division
Meiosis division
2 daughter cells
4 daughter cells
46 chromosomes
23 chromosomes
Skin, muscle, and blood cells
Gamete (sperm and ova cells)
Asexual reproduction
Sexual reproduction

8. Important Terms
Gamete – a mature haploid cell (sperm or ova) that is able to join with the opposite haploid cell, and produce a zygote
Zygote –a cell formed by the union of two gametes (sex cells; sperm and ova/egg)
Genes – set of instructions for an inherited trait; located on chromosomes.

9. Advantage of Sexual Reproduction
Produce offspring with genetic material from both parents which creates a greater variety in the species
More adaptations in species allow for greater adaptation to changes in the environment
In species where males help raise the offspring, it is possible to produce more offspring with a greater chance of survival

10. Organisms reproduce more slowly and take longer to colonize
Disadvantages of Sexual Reproduction
Organisms reproduce more slowly and take longer to colonize
Sexual population grows twice as slowly as the asexually producing one
If a mate is not found, the female’s egg is wasted
Parents often have to raise the offspring/offspring are not self-sufficient