Understanding Sexual and Asexual Reproduction in Living Organisms

1. Sexual and Asexual Reproduction Saturday, 04 January 2020 Learning question: What is the difference between sexual and asexual reproduction?

2. Learning objectives: Distinguish between sexual and asexual reproduction

3. Key words: • Sexual reproduction • Asexual reproduction

4. Sexual and Asexual Reproduction • Living things use lots of different strategies for producing offspring, but most strategies fall neatly into the categories of either sexual or asexual reproduction.  • Asexual reproduction generates offspring that are genetically identical to a single parent. • In sexual reproduction, two parents contribute genetic information to produce unique offspring.

5. Task • Click on the link http://learn.genetics.utah.edu/content/basics/reproduction/ • Click or tap an image of an organism. • After reading a description, you'll get to vote on whether you think the organism reproduces sexually, asexually, or both. • Use the definitions on the previous slide to help you decide and discuss why you chose the option you went for.

6. Sexual Reproduction • Get genes from both mum and dad • Inherits mixture of features from both parents • Females produce sex cells (gametes) called eggs and male gametes are called sperm • A sperm and egg fuse together to make the offspring = fertilisation

9. Finish this sentence • Sexual reproduction is … Include the following words: • Genes • Mum and Dad • Different • Features • Half • Gametes

10. Sexual reproduction is when information is carried by sperm and egg cells (the gametes) meet. The information is carried on genes and comes from two different parents, with different features. The offspring (baby) now has half the information from mum and half from dad.

11. Asexual reproduction • Offspring produced in this way get all their genes from just one parent • So have exactly the same genes as parent • All are clones of the parent

12. Doesn’t need sex cells • Individual just splits in two e.g amoeba, bacteria • Or a part divides off e.g. hydra, starfish

13. Bacteria reproducing asexually

17. Finish this sentence • Asexual reproduction is ….. Include the following words: • Genes • Parent • Splits • Divides • Clone

18. Sexual vs Asexual Reproduction Advantages of Asexual reproduction • Only one parent needed • All offspring are clones Advantages of Sexual reproduction • All offspring are different

20. Comparing Sexual and Asexual Reproduction

21. Questions • What are the disadvantages of asexual reproduction? • Explain why variation is sometimes an advantage and sometimes a disadvantage • Start off with one bacterium and assume it reproduces once every 20 minutes. How many bacteria would you have after 3 hours?

22. What is a clone? A clone is genetically identical to its “parent”

23. Cloning • Dolly the sheep was the first mammal to be cloned from the DNA of an adult. • Here she is with her first-born lamb, Bonnie. • Roslin Institute, Edinburgh, 1996

24. Animal Cloning • The goal of cloning is to take control of the reproductive process. • You are able to select the specific combination of genes to get what you want. • That's appealing to people who breed animals.

25. Cloning Dolly the Sheep

26. Where next??

28. Questions • Was cloning Dolly the sheep, a mammal like us, a good idea? • Are there any circumstances in which producing a human clone could be acceptable?