1. Types of Sexual Reproduction

2. Vocabulary Conjugation, hermaphrodite Stamen, filament, anther, pollen
Pistil, stigma, style, ovary, petals, petals, sepals, pollination
external fertilization, internal fertilization

3. Conjugation
Conjugation occurs when two unicellular organisms transfer or exchange some of their genetic material.
Some bacteria and certain protists like Paramecium
Example: bacteria like E.coli one cell copies an extra piece of DNA (called a plasmid) and donates the plasmid copy to another cell

4. Autogamy – Self Fertilization
“Auto” means “self”
Autogamy means an organism can fertilize itself
Hermaphrodites are organisms that produce both male and female sex cells within the same individual.
Hermaphrodites occur in plants and some animals that are attached to one location and/or rarely come in contact with other individuals of their species.
Eg many aquatic organisms (sponges and barnacles), Earthworms, flowers
Although autogamy is similar to asexual reproduction, in that there is no input of genetic diversity from a partner, the recombination of chromosomes from the male and female gametes results in offspring with slightly altered genetic information, which can therefore look phenotypically different from their parents. Most plants and earthworms reproduce by autogamy. It is sometimes possible for hermaphrodites to reproduce with other hermaphrodites. In this case, genetic diversity does increase within the population.

5. Compare Autogamy to Asexual Reproduction
It is possible for hermaphrodites to reproduce with other hermaphrodites. In this case, genetic diversity does increase within the population.

6. Compare Autogamy to Asexual Reproduction
Similar: No partner, No input of genetic diversity.
But: the recombination of chromosomes from the male and female gametes results in slightly genetically different offspring
It is possible for hermaphrodites to reproduce with other hermaphrodites. In this case, genetic diversity does increase within the population.

7. Allogamy – Cross Fertilization
Allogamy is the fertilization of an egg from one individual with the sperm of another .
Occurs in most complex animals and some plants
Eg. Conifers such as pine and fir trees have separate male and female cones on the same plant.
Some species have separate male and female flowers on the same plant
Poplar trees have separate sexes on separate plants.

8. Fertilization – Fusion of Nuclei
Fertilization is the process in which the nuclei of the male and female gametes fuse together to produce a single cell called a zygote.
Sperm cells have long tails “flagella”.
Egg cells are much bigger and lack flagella. What does the presence or absence of flagella say about the cells motility?

9. External Fertilization
gametes meet outside of the parents
The female deposits unfertilized eggs and males release sperm over the eggs.
Common in fish and amphibians
h?v=q50Yphp1gzI
fertilization (the exceptions are aquatic mammals, sharks, and some other special types of fish).
External fertilization usually occurs among organisms living in aquatic environments. Land animals generally have specialized organs for internal fertilization.

10. Advantages of External Fertilization
Energy Efficient: Requires very little effort as the sperm and egg can randomly meet
Easier to find mates as the gametes released can drift (wind, water etc).
Low Parental Burden: Female does not have to physically carry the developing offspring
Many Offspring, More genetic variation
No specialized structures required to have gametes meet

11. Disadvantages of External Fertilization
Egg, zygotes, young susceptible to environment (drying out) and predation.
No guarantee that eggs will be fertilized.
Large numbers of eggs need to be produced to ensure some survival.

12. Internal Fertilization

13. Internal Fertilization
Gametes meet inside female’s body
Requires specialized structures to ensure meeting of gametes
Occurs in mammals, reptiles, birds, and some types of fish 
All land dwellers need to fertilize this way because sperm still prefer swimming
Need specialized structures. Penis

14. Advantages of Internal Fertilization
Better chance gametes will meet, greater change of fertilization
Controlled environment: wet environment, temperature regulation, protection from predators
More stringent mate selection
Video of sneaky fish:

15. Disadvantages of Internal Fertilization
Mating can be risky, partners vulnerable during intimate contact
Complex courtship and mating behaviours
wKqopo
Limited amount of offspring being produced at any given time. 
Parents must care for young through out gestation
Specialized structures are required to ensure the meeting of gametes

16. Bower Bird
Bower Bird video

17. Puffer Fish

18. Internal and External Fertilization
Name an organism for each method
How is internal fertilization an advantage over external?
Why do you think organisms that reproduce using external fertilization release a large number of eggs and sperm?

19. Check your understanding
How does the process of fertilization occur?
What is needed for fertilization to occur?
Describe the different forms of fertilization and give an example of an organism that uses them.

20. Advantages of Asexual Reproduction
No partner necessary (energy efficient)
Fast – each organism can produce many offspring  rapid population growth
Offspring mature quickly
Offspring are already adapted to environment
All advantages help an organism become establish de quickly and successfully in the conditions provided by its environment.
But what if conditions change?
many Food crops depend on asexual reproduction – new plants can be grown quicly and in large number when they are produced this way. The plants that come from themhave predictable qualities that consumers expaect. But what if there is o rain for a long time. Or if the plats are invaded by a disease? Because all plants are genetically identical, they will all respond the same way --. Become diseased and possible die.

21. Disadvantages of Asexual Reproduction
Less genetic variation - all offspring are clones and therefore all susceptible to disease
Harder for species to adapt to environment
Slows down evolution
All advantages help an organism become establish de quickly and successfully in the conditions provided by its environment.
But what if conditions change?
many Food crops depend on asexual reproduction – new plants

22. Why Sex? Possible Benefits:
Genetic variation:
offspring’s DNA is different and therefore may be better prepared for any changes in the environment
Any disease that affects some of the offspring will not affect all of them
 some will still be able to survive and reproduce
Variation in DNA leads to evolution
Why would organisms need to evolve? Is change good? Environment changes, organisms need to adapt to changing environment.

23. Why Sex? Disadvantages
Time and Energy costly –finding a mate, courtship is time and resource costly
Usually fewer offspring produced
Slower – gestation (development of fetus inside womb) and longer time for offspring to mature
More energy investment into raising young
Time and Energy costly –finding a mate, courtship is time and resource costly (may expose individuals to predators, disease, or harsh conditions. This can delay reproduction and organism’s ability to become established in its environment. Fewer offspring also then takes longer to establish in environment
Usually sacrifices fitness of one sex to the other.
Slower
Why would organisms need to evolve? Is change good? Environment changes, organisms need to adapt to changing environment.
Bower bird nest
Jasper story
Elephant gestation months

24. Strange Animal Behaviour
HW: Read 83-84, 86,
HW: Answer CYU p87 #2,3,5,8-11,14

25. Compare Asexual and Sexual Reproduction
Feature
Asexual
Sexual
Number of parents
Number of offspring
Variety of offspring
Speed of reproduction
Timing
Energy cost

26. Feature
Asexual Reproduction
Sexual Reproduction
Number of parents
One
two
Number of offspring
Usually many
Usually few
Variety of offspring
Genetically identical
Genetically different
Speed of reproduction
Usually fast
Usually slow
Timing
Anytime, once mature
Once mature, only when a mate is available