1. Asexual vs. Sexual Reproduction

2. Two basic reproductive modes Asexual reproduction Asexual reproduction - Requires only one parent - Requires only one parent - Offspring are genetically identical to - Offspring are genetically identical to parent and each other due to mitosis. parent and each other due to mitosis. Sexual reproduction Sexual reproduction - Requires meiotic cell division in two - Requires meiotic cell division in two parents. parents. - Produces genetically variable offspring with - Produces genetically variable offspring with different combinations of parental genes. different combinations of parental genes.

3. Asexual reproduction is the primary form of reproduction for single-celled organisms such as archaea, bacteria, and protists. Many plants and fungi reproduce asexually as well. single-celled organismsarchaeabacteriaprotistsplantsfungisingle-celled organismsarchaeabacteriaprotistsplantsfungi

4. Types of asexual reproduction Binary fission Binary fission Budding Budding Vegetative reproduction Vegetative reproduction Regeneration Regeneration Parthenogenesis Parthenogenesis

5. Budding Miniature animal begins as a bud on the Miniature animal begins as a bud on the adult and becomes independent. adult and becomes independent.

6. Binary fission Cell splits and replicated DNA goes with each part Cell splits and replicated DNA goes with each part Prokaryotes and Bacteria Prokaryotes and Bacteria + Fast and easy + Fast and easy - Everybody has the same DNA - Everybody has the same DNA

7. Asexual reproduction by regeneration in flatworms

8. Parthenogenesis In some insects, fish, amphibians and reptiles the eggs produced by females develop directly into adults without being fertilized by sperm. In some insects, fish, amphibians and reptiles the eggs produced by females develop directly into adults without being fertilized by sperm.

9. Asexual Reproduction - Advantages Rapid population growth Rapid population growth Requires less energy to reproduce Requires less energy to reproduce All organisms are able to reproduce as All organisms are able to reproduce as opposed to just a female population opposed to just a female population Only one organism may begin an entire Only one organism may begin an entire population population Less likely to become extinct Less likely to become extinct An exact replica of the parent An exact replica of the parent

10. Cloning in large numbers

11. In Asexual reproduction, offspring are typically genetically similar to their parent.

12. The lack of genetic recombination results in fewer genetic alternatives than with sexual reproduction. The lack of genetic recombination results in fewer genetic alternatives than with sexual reproduction.genetic recombinationgenetic recombination Many forms of asexual reproduction, for example budding or fragmentation, produce an exact replica of the parent. Many forms of asexual reproduction, for example budding or fragmentation, produce an exact replica of the parent. replica Asexual reproduction disadvantages

13. Asexual reproduction is inferior because it stifles the potential for change. Asexual reproduction is inferior because it stifles the potential for change. There is also a significantly reduced chance of mutation or other complications that can result from the mixing of genes. There is also a significantly reduced chance of mutation or other complications that can result from the mixing of genes.mutation

14. Sexual reproduction in animals Requires the production of gametes (egg and sperm), which are haploid cells. Requires the production of gametes (egg and sperm), which are haploid cells. Gametes are produced from diploid cells by meiosis. Gametes are produced from diploid cells by meiosis. Fusion of egg and sperm (fertilization) produces a diploid zygote, which divides into new diploid animal. Fusion of egg and sperm (fertilization) produces a diploid zygote, which divides into new diploid animal.

16. Fusion of gametes in plants

17. Sexual Reproduction Advantages Allows for more diversity among a species Allows for more diversity among a species Higher probability of mutation and survival Higher probability of mutation and survival in periods of change in periods of change

18. Advantages of sexual reproduction Offers the opportunity to produce different combinations that can make the population better able to keep up with changes in the environment.Offers the opportunity to produce different combinations that can make the population better able to keep up with changes in the environment. Species with recombination can bunch harmful mutations together and eliminate several in a single "genetic death.“Species with recombination can bunch harmful mutations together and eliminate several in a single "genetic death.“

19. Sexual reproduction disadvantages Two parents are required Increased likely hood of something going wrong A much more complicated and lengthy process.

20. A lineage that reproduces sexually has a higher probability of having more members survive due to the genetic recombination that produces a novel genotype through adaptations.

21. Interesting examples Anemone fishes are characterized by being protandrous hermaphrodites which means that all fish develop into males first and then potentially into females later. More than one anemone fish may reside in the same anemone, however if the female were to be removed from the group or die, the largest male would then become female. Females control males through aggressive dominance, thereby controlling the formation of other females.

22. Some species alternate between sexual and asexual reproduction, an ability known as heterogamy, depending on conditions. Some species alternate between sexual and asexual reproduction, an ability known as heterogamy, depending on conditions. Examples- Freshwater crustacean Daphnia reproduces by parthenogenesis in the spring to rapidly populate ponds, then switches to sexual reproduction as the intensity of competition increases. Examples- Freshwater crustacean Daphnia reproduces by parthenogenesis in the spring to rapidly populate ponds, then switches to sexual reproduction as the intensity of competition increases.Daphniasexual reproductionDaphniasexual reproduction Many protists and fungi also alternate between sexual and asexual reproduction. Many protists and fungi also alternate between sexual and asexual reproduction.