1. REPRODUCTION Reproduction – The process of producing offspring
Two parents – similar looking offspring
One parent – identical looking offspring
Two Types
Asexual
Sexual

2. ASEXUAL REPRODUCTION
A single parent passes a complete copy of its genetic information to each of it’s offspring
Offspring are identical to parents
Four different types of asexual reproduction

3. Binary Fission Prokaryotes (bacteria) DNA is replicated
DNA Attaches to the cell membrane
Cell splits – each having the same DNA

4. FRAGMENTATION
Body breaks into several pieces, some or all of the fragments regrow missing parts and develop into adults
Ex. Starfish, some worms, some plants

5. BUDDING New individuals split off from existing ones
Ex. Hydra, potatoes, jellyfish, corals

6. PARTHENOGENESIS
Process by which females make a viable egg that grows into an adult without fertilization
Ex. Water fleas, some worms, some bees

7. SEXUAL REPRODUCTION Meiosis
Purpose is to produce cells that are genetically different from parents
Offspring has traits from each parent, but is different
Male – sperm
Female - egg

8. Meiosis Genes are located on chromosomes
Each species has a specific number of chromosomes
Mosquitoes = 6
Chimpanzees = 48
Humans = 46
Each egg and sperm have 22 autosomes and 1 sex chromosomes and when they come together we have 46

9. Haploid vs.Diploid Diploid = two sets of chromosomes (46)
Haploid = one set of chromosomes (23)
Homologous chromosomes = identical to each other
Autosomes = chromosomes that do not determine sex
Sex chromosomes- determine sex (XX-females, XY-males

10. Meiosis I Meiosis I – 1st nuclear division
Follows a period of interphase - cell growth
Divided into 4 phases

11. Prophase I – chromosomes form from DNA strands, spindle fibers appear, homologous pairs line up and form a tetrad
Crossing over may occur – which is when chromosomes exchange portions of their chromatids, resulting in an exchange of genes
Heterogenous
chromosomes

12. Metaphase I – tetrads move to the center of the cell

13. Anaphase I – homologous pairs of chromosomes separate
Anaphase I – homologous pairs of chromosomes separate. Each chromosome is still composed of two chromatids joined by a centromere

14. Telophase I – cytoplasm divides, forming 2 daughter cells

15. Meiosis II (2nd nuclear division)
Occurs in each cell formed during meiosis I, and is not preceded by DNA replication
Divided into 4 phases

16. Prophase II – new spindle fibers form

17. Metaphase II – chromosomes move to the center of the cell

18. Anaphase II – the centromeres joining the chromatids divide freeing the sister chromatids from each other, and the chromatids move to opposite poles of the cell

19. Telophase II – spindle dissolves, nuclear membrane forms, and cytokinesis occurs. Produces four daughter cells

20. Formation of egg and sperm – forms gametes (sexual reproductive cells)
Meiosis in males produces 4 sperm
Meiosis in females produces 1 egg and 3 polar bodies which will disintegrate
Meiosis allows for genetic recombination. This allows for variation between parent and offspring

21. GENETIC VARIATION
Advantageous for a population in order to survive in their environment
Polar bears with a gene for thick fur vs. those with a gene for thin fur. ( Who would survive?)
Only made possible by sexual reproduction due to rearranging of genes
Read pages, 253 – 254 with a partner together summarize the 3 keys to genetic variation

22. MULTICELLULAR LIFE CYCLES
Life Cycle – all the events in the growth and development of an organism
Two types of life cycles
Diploid
Haploid

23. DIPLOID LIFE CYCLE Most animals have this
Diploid cells go through meiosis and forms gametes (sperm and egg) which join together during fertilization
Result is the haploid gamete

24. HAPLOID LIFE CYCLE Occurs in fungi and some protists
A zygote goes through meiosis immediately after it is formed and makes new haploid cells
Haploid cells divide by mitosis and create new individuals

25. Alternation of generations
Plants and multicellular organisms that alternate between diploid and haploid
Sporophyte; diploid phase of a plant – produces spores through meiosis
Gametophyte; haploid phase that produces gamete by mitosis