1. Methods of Reproduction Sexual and Asexual Reproduction

2. Asexual Reproduction: requires only 1 parent and the offspring are an exact copy of the parent---a clone

3. Asexual Reproduction: Organisms that reproduce asexually cannot develop much variety, because they are “copying” the original organism exactly.

4. Methods of asexual reproduction: Binary fission Budding Fragmentation Parthenogenesis Spores Regeneration Vegetative Reproduction

5. Binary fission Single-celled organisms (Amoeba, paramecium, euglena) which use asexual reproduction can do so simply by dividing into two equal halves.

6. When conditions are good, such as plenty of water, food, right temperatures, etc., binary fission is a very effective way of producing many, many offspring. For example, the cell of a Paramecium can divide, grow, and divide again in the space of 8 hours.

7. Spore Formation Fungi Fern Spore Formation –happens in fungi, green algae, moulds and non flowering plants (e.g. ferns) –spores are produced and each spore develops into offspring which are identical to parent

8. Budding- an offspring grows out of the body of the parent. Hydra Budding offspring Cactus Budding

9. Yeast - budding Budding In yeasts the cell does not divide equally in two halves; instead, there is a large mother cell and a smaller daughter cell.

10. Fragmentation In this form, the body of the parent breaks into distinct pieces, each of which can produce an offspring. Example: Tape Worm

11. Regeneration A piece of the organism breaks off – and the organism can regrow from that piece. Pieces of coral broken off in storms can grow into new colonies. A new starfish can grow from one detached arm.

12. Parthenogenesis Parthenogenesis is a form of asexual reproduction in which females produce eggs that develop without fertilization.Parthenogenesis is a form of asexual reproduction in which females produce eggs that develop without fertilization. Parthenogenesis is seen to occur naturally in some invertebrates, along with several fish, amphibians, and reptiles as well as in many plants.Parthenogenesis is seen to occur naturally in some invertebrates, along with several fish, amphibians, and reptiles as well as in many plants. There are no known cases of parthenogenesis in mammals.There are no known cases of parthenogenesis in mammals.

13. Vegetative Reproduction –does not involve seeds –some offspring can grow from cuttings (e.g. coleus), runners (e.g. strawberries), tubers (e.g. potatoes) or bulbs (e.g. tulips)… which are part of the parent plant

14. What is sexual reproduction? Requiring 2 parents –male and female (egg & sperm) The egg and sperm join (zygote) to form an entirely new organism Offspring are different from the parent organism because

15. Sexual Reproduction: Requiring 2 parents (egg & sperm) Combining different genetic material

16. Methods of sexual reproduction: Pollination External Fertilization Internal Fertilization

17. Sexual Reproduction in Plants pollen (male) + ovule (female) → single-celled zygote → multi-celled embryo (contained in a seed) → new individual

18. Pollination flowers are designed to lure insects to help with the pollination process –also wind, mammals and birds can transport pollen

19. External Fertilization External fertilization usually requires a medium such as water, which the sperms can use to swim towards the egg cell. External fertilization usually occur in fish and amphibians. The females lay the eggs in the water and the male squirts the sperm in the same area.

20. Internal Fertilization Fertilization occurs within the female. Internal fertilization occurs in mammals, insects, birds, reptiles. –Mammals (gorillas, lions, elephants, rats, zebras, and dolphins have live births) –Insects, birds, reptiles lay amniotic eggs

21. *Offspring obtain energy from the mother via a placenta. Placenta: The placenta is an orgn that connects the developing fetus to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply Placenta

22. The Amniotic Egg Allowed for reproduction to occur on land Reptiles First to acquire this method of reproduction Also found in birds and mammals (no shell) Fertilization must be internal

23. Sexual Reproduction Summary Male Gamete Female Gamete Type of Union Result of Union Final Result Plants pollen ovule (egg) pollination single cell zygote multi-cell embryo (in seed) Animals spermeggfertilization single cell zygote multi-cell embryo

24. Which is Better? It depends! Asexual Reproduction advantages –does not require special cells or a lot of energy –can produce offspring quickly –in a stable environment creates large, thriving population disadvantages –limited ability to adapt –face massive die-off if environment changes Sexual Reproduction advantages –lots of variation within a species –able to live in a variety of environmental settings –able to adapt to changes in the environment disadvantages –needs time & energy –produce small populations