1. 1
Meiosis

2. Reproduction Reproduction is the process of producing offspring
Some offspring are produced by two parents
Some offspring are produced by just one parent
Whether an organism is identical or similar to its parent is determined by the way that the organism reproduces

3. Asexual Reproduction
When a single “parent” passes a complete copy of its genetic information to each of its offspring
An individual formed by asexual reproduction is genetically identical to its parent

4. Types of Asexual Reproduction
Binary Fission: Reproduction performed by most prokaryotes

5. Types of Asexual Reproduction
Fragmentation: A kind of reproduction in which when the body of an organism breaks into several pieces, some or all of these fragments re-grow missing parts and develop into complete adults

6. Types of Asexual Reproduction
Budding: In budding, new individuals split off from existing ones

7. Types of Asexual Reproduction
Parthenogenesis: A process in which a female makes an egg that grows into an adult without being fertilized by a male

8. Sexual Reproduction Practiced by most eukaryotic organisms
In sexual reproduction, two parents give genetic material to produce offspring that are genetically different from their parents
Each parent produces a gamete (reproductive cell)
Gamete from one parent fuses with gamete from another parent to form a zygote
This process is called fertilization

9. Germ Cells & Somatic Cells
Germ cells are cells that are specialized for sexual reproduction (sperm & egg)
Somatic cells are all other body cells. They DO NOT participate in sexual reproduction

10. Asexual vs. Sexual Reproduction
Asexual reproduction
Advantages: Very efficient - can reproduce a lot in a short period of time
Disadvantages: Organisms can die off easily if the environment changes

11. Asexual vs. Sexual Reproduction
Advantages: Produces genetically different organisms so a population could survive in a changing environment
Disadvantages: It could take a lot of energy to find a mate

12. Chromosome Number Genes are located on Chromosomes
Each chromosome has thousands of genes that play an important role in determining how an organism develops and functions
Each species has a unique number of chromosomes (mosquitoes = 6; humans = 46; ferns = 500)
If an organism has too many or too few chromosomes, the organism may not develop and function properly

13. Chromosome Number
When fertilization occurs, two cell combine to form a zygote
The gametes that form a zygote have only ONE copy of each chromosome (not two, like somatic cells)
This ensures that the resulting zygote has the correct number of chromosomes

14. Haploid vs. Diploid
Cells that are diploid (somatic cells) have two sets of chromosomes (2n)
Cells that are haploid (gametes) have one set of chromosomes (n)

15. Homologous Chromosomes
Each diploid cell has pairs of chromosomes made up of two homologous chromosomes
Homologous chromosomes are chromosomes that are similar in size, in shape, and in the kinds of genes they contain
Each chromosome in a homologous pair comes from one of the two parents

16. Autosomes and Sex Chromosomes
Autosomes are chromosomes that do not determine the sex of an individual
Sex chromosomes have genes that determine the sex of an individual
All humans receive an X chromosome from their mother
If they receive an X chromosome from their father, the human is a girl (XX)
If they receive a Y chromosome from their father, the human is a boy (XY)

17. Meiosis
During meiosis, a diploid cell goes through two divisions to form four haploid cells

18. Mitosis vs. Meiosis
Mitosis creates 2 daughter cells that are genetically identical
Meiosis creates 4 daughter cells that are genetically different
Mitosis makes cells that are used during growth and repair – happens in body cells
Meiosis produces cells that allow an organism to reproduce sexually – only happens in reproductive structures

20. Genetic Variation Genetic variation is advantageous for a population
It can help a population survive a major environmental change
Genetic variation is made possible by SEXUAL reproduction