Do Now

1. Do Now • What are the preexisting cells called before they divide? Parent Cells 2. What are two new cells called after cell division? Daughter Cells 3. What does reproduction mean? Formation of new individuals

2. AIM: What is the difference between asexual and sexual reproduction?

3. Reproduction • The formation of new individuals • One of most important traits of living things For a small organism with one cell, they can just carryout cell division – no dating, no breakups!

4. Let’s remember… • What classification do organisms have to be to be able to mate with each other? • Species – organisms must have the same species classification to mate • Ex: Giraffe cannot mate with a horse because they are not the same species

5. Two types of reproduction • Asexual Reproduction • Sexual Reproduction

6. Asexual Reproduction • The production of genetically identical offspring from a single parent • The daughter cells have the SAME DNA • “a-” prefix means “without” – so reproduction without fusing reproductive cells Just like regular cell division!

7. Asexual Reproduction • Relatively simple, efficient, and effective • Enables populations to increase in numbers quickly • Can occur in single-cellular or multicellular organisms Ex: Bacteria, Hydra

8. Review • Asexual reproduction of organisms normally results in new organisms that contain cells with • more chromosomes than are found in the cells of the parent • half the number of chromosomes • the same number of chromosomes • fewer chromosomes that are found in the cells of the parent

9. Review • If an organism reproduces asexually, its offspring will most likely be • genetically different from each other • produced from specialized cells known as gametes • genetically identical to the parent • produced as a result of fertilization

10. Sexual Reproduction • The fusion of two separate parent cells • Offspring produced by sexual reproduction inherit some of their genetic information from each parent

11. Sexual Reproduction • Most plants and animals reproduce sexually • Some single-celled organisms do, too Ex: Humans, flowers, dogs, cats

12. Review • The members of a certain species of grass in a lawn are genetically identical. The best explanation for this observation is that the species most probably reproduces • by an asexual method • after pollination by the wind • after pollination by a particular species of bee • by identical sperm fertilizing the eggs

13. Reivew • The diagram shows a sequence of events. The sequence of events from rabbits to zygote is known as • sexual reproduction • fission • sporulation • vegetative propagation

14. Review • A colony of red bacteria is allowed to reproduce for 16 generations.  A scientist examines the colony at the end of this time and notes that all the individuals are almost identical in all characteristics.  This evidence suggests that the bacteria • did not receive the proper nutrients • reproduced sexually • exchanged genetic material • reproduced asexually

15. Review • Which two organisms in the diagram typically reproduce asexually? • A and H • C and F • E and G • F and I