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Sexual Reproduction

Sexual Reproduction

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Sexual Reproduction

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  1. Sexual Reproduction

  2. Fertilization • Recall that sexual reproduction occurs when one haploid – the sperm – fuses together with another haploid – the egg. • Each haploid contains 23 chromosomes. • When they combine they produce a zygote (an offspring)

  3. Alleles • Gene’s – Recall that Gene’s are a particular region of DNA that helps create the amino acids with then produce the protein to create the characteristics for each organism. • Alleles are different versions of genes and here we can have a recessive gene and a dominate gene • Each gamete will carry the alleles, fuse together with the other gamete and then there is a mathematical way to figure out the type of characteristics an offspring will have.

  4. Punnet Squares • http://www.youtube.com/watch?v=_ksIajiPUAU • The dominategeneis a big letter and the recesivegeneis a small letter. • Create a punnet square if the father’s eye colour gamete has an allele of Bb (Brown, blue) and the mother’s gamete has an allele of bb (blue, blue). • Take one of those offspring and say it marries a person how has an Gb (Green, blue) eye colour, what are the possible offspring and the percentage of each.

  5. Advantage/ Disadvantage Sexual Reproduction

  6. Advantage/ Disadvantage Asexual Reproduction Examples: Bacteria, Plants, Vegetation ( Strawberry Plants, Potatoes)

  7. Different Offspring's • -- Identical (sometimes called Paternal or Maternal Twins)  They're created from combining one egg and one sperm.  After a few days the one embryo will divide and create two identical babies. • -- Fraternal (sometimes referred to as not-identical twins) are created from two eggs that get fertilized with two separate sperm.  Basically they are no more alike than any other brothers and sisters. • -- Conjoined twins are created from one egg and one sperm, but the embryo does not fully separate .

  8. Conjugation • Conjugation occurs when two unicellular organisms transfer or exchange genetic material. • Conjugation happens in bacteria and certain protists (algae and fungi) • Recall that bacteria is created asexually via binary fission (they are able to create an exact replica of itself in seconds) • Bacteria will create extra DNA called plasmid. This extra bit of DNA is kind of mutated DNA in where it can resist forms of antibiotics and as such will become resilient and continue to reproduce.

  9. Conjugation • 1. Binary Fission occurs and a malting bridge is created • 2. The replicated bacteria connects with the malting bridge • 3. The donor bacteria transfers the plasmid to the replicated DNA • 4. The two bacteria’s separate and continue to share their plasmid with other bacteria’s.

  10. Hermaphrodites • A Hermaphrodite is an organism that produces both male and female sex cells. • Hermaphrodites can mate with any other member of its species, usually is CANNOT fertilize their own eggs with their own sperm. • Earthworms are hermaphrodites. When they meet, they attach to each other and fertilize each others eggs. • They will detach and fertilization will occur. • They create a mucus ring called the clitellum - this can be found around the thicker part of the worm. • The mucus ring will slip off the worm into the soil and act as a cocoon for the fertilized eggs. The offspring will hatch in a few days.

  11. EarthWorms • When they connect, they connect near the “genital pores” where they exchange each others sperm to fertilize each others eggs. • The clitellum is where the eggs are fertilized, this is the mucus ring that will fall off in the soil.

  12. Flowering Plants • Stamen – contains the Anther and Filament. This is the male reproductive structure of the plant. • Pistil – contains the Stigma, Style and Ovary. This is the female reproductive structure of the plant.

  13. Flowering Plant • The filamentis a stalk that supports the anther. The anther is at the top of the stamen and produces pollen. • The pollen grains contain the male gametes. • The stigma – the top of the pistil – and it receives the pollen grains. • The pollen grains travels down the tube like style to the ovary.

  14. Flowering Plants • Sometimes wind will move the pollen from one plant to another. • Other times another organisms – like bees – will be attracted to the colour of the petals and the pollen attaches to them. These organisms then travel to another plant and deposit the pollen onto the pistil. • This is known as cross contamination. • The pollen then fertilizes the eggs in the ovary. The eggs turn into seeds that spread into the soil and grow.

  15. Separate Sexes • Organisms that require the need to mate with opposite sexes within their spices can produce offspring in two different ways • External Fertilization • Internal Fertilization

  16. Separate Sexes • Many animals, such as fish and birds, use external fertilization to create offspring. • The female releases her eggs into the water (fish) or in a nest (birds). • The male then releases its sperm over the eggs. • Since the fertilization occurs outside the body, this is called external fertilization

  17. Separate Sexes • Some animals, both aquatic and non-aquatic, requires sperm to be deposited inside the body of a female. • Like with external fertilization, the sperm needs to come into contact with eggs in order for offspring to be produced. • In this case, since the sperm and egg meet inside the body, we call this internal fertilization.

  18. Assignment • Page 82 Questions - 1, 2, 4, 8, 9 (b,c,d), 10 • Page 87 Questions – 2, 3 & 4, 6, 7, 8, 14 • Group 1 –pg 82 1, 2, 4, 8 • Group 2 –pg 82 9 (b,c,d), 10, pg 87 2, 3 &4 • Group 3 –pg 87 6, 7, 8, 14