1. Sexual vs Asexual Reproduction Mode of Reproduction 6.12D

2. Students will… Identify examples of asexual and sexual reproduction Recognize that asexual reproduction results in more uniform offspring Realize that sexual reproduction results in more diverse offspring (offspring = babies, young, children)

3. Purpose of Reproduction One of the characteristics of all living things is the ability to reproduce. During reproduction, organisms make more of their own kind. The purpose of reproduction is to make sure the species continues to live on

4. Young have characteristics in common with the adults Reproduction is the process by which an organism produces others of its kind.

5. Offspring Offspring are the products of reproduction.

6. ASEXUAL REPRODUCTION

7. Asexual Reproduction A new organism is produced from a single organism The offspring will have identical genetic information to the parent organism Simple form of reproduction that occurs in more basic organisms Each bud on this cactus can grow into a new plant identical to the parent.

8. Types of Asexual Reproduction Binary fission Budding Regeneration

9. Binary Fission The simplest method of reproduction A ‘mother cell’ splits into two identical ‘daughter cells.’ The results offer no variation Often occurs in organisms such as bacteria or protozoans

10. Examples of binary fission

11. Budding Budding occurs when a bulge grows on the side of the parent organism and eventually breaks off to become a separate organism. Often occurs in plants.

12. Budding

13. Regeneration Regeneration is the ability to re-grow lost or damaged tissues or organs. This occurs commonly in some invertebrates such as starfish and worms. If an entirely new organism can be grown from a piece of the parent organism, then it is considered a form of asexual reproduction.

14. Examples of regeneration This starfish is re-growing 3 of its arms. A starfish has remarkable regeneration abilities. Oyster collectors used to cut up starfish thinking they had killed them. In reality, each piece of the starfish that contained a part of the central disc was able to grow into a whole new organism.

15. Lizard Tails These lizards have lost their tails which will grow back through the process of regeneration. However, since the tail cannot grow a new lizard, this regeneration is not a form of asexual reproduction.

16. Review of Asexual Reproduction Requires only one parent Only one set of genetic material is involved No mixing of genes Produces offspring that are identical to the parent Offspring have the identical genetic information as the parent so no variety is produced

17. SEXUAL REPRODUCTION

18. Sexual reproduction Requires a male cell and a female cell Requires two parents and two sets of genetic material Offspring receive a combination of genetic material Results in variety More complex form of reproduction Occurs in most animals Also occurs in many plants (seeds contain genetic material from an egg cell that is fertilized by a sperm cell)

19. Sexual reproduction requires male and female sex cells.

20. Offspring receive genetic information from 2 parents Results in variety!

21. Review Asexual reproduction results in offspring that are genetically identical to the single parent. Sexual reproduction combines genetic information from two parents and results in a new combination of genetic material that is different from mother or father. Simpler organisms reproduce asexually More complex organisms use sexual reproduction Plants often use both asexual (budding) and sexual (flowering) reproduction.

22. Summary of differences between asexual and sexual reproduction Number of parents 1 2 (one male, one female) Make up of offspring Genetically identical to parent and other offspring Genetically unique Advantages Rapid reproduction – quickly builds population numbers Produces more variation DisadvantagesDisease or other conditions may kill off the entire population Slower process

23. By Kingdoms Bacteria and Archae – Reproduce asexually Protists – both sexual and asexual reproduction Fungi – both sexual and asexual reproduction Plants – both sexual and asexual reproduction Animals – usually sexual reproduction

24. Question for discussion