Sexual Reproduction

What is Sexual Reproduction Sexual Reproduction in plants and animals is the union of two sex cells, called gametes to produce a new individual. Sex cells from females are called eggs or ova Sex cells from males are called sperm The union of the sperm cell with the egg cell is called fertilization. Sexual reproduction produces offspring that have some traits from one parent and some traits from the other.

Meiosis Gametes (sperm and eggs) are produced through a cell division process called Meiosis. Meiosis is very similar to mitosis and has very similar steps but goes through the steps twice. Meiosis has two parts: Meiosis 1 and Meiosis 2 Both parts have the same phases as mitosis in the same order. Meiosis 1 does not produce cells with the same genetic material- the chromosomes shake up and trade genetic material. Meiosis 2 takes the mixed chromosomes and pulls them apart making the final germ cells.

Mitosis vs Meiosis Mitosis produces two daughter cells that are exact copies and have the same number of chromosomes as the parent cell Meiosis produces four daughter cells that have half the number of chromosomes as the parent cell These gametes produced in meiosis only have half the number of chromosomes because they then meet another gamete and create a zygote with the other half of chromosomes. This zygote becomes an embryo (Baby)

Hermaphrodites A Hermaphrodite is an organism that can produce both male and female reproductive cells Some Hermaphrodites can reproduce sexually with a partner or sexually by themselves through a process called self fertilization Some can also change their sex to fit the needs of their environment

Sexual Reproduction In Plants We know they do a lot of asexual reproduction with spores and grafting but how does a plant sexually reproduce? Plants have special parts for reproduction that serve similar functions to sexual reproduction in animals. Video https://www.youtube.com/watch?v=YqM6rgB_l_o https://www.youtube.com/watch?v=2ycl2E9r-_o

Self Pollination: occurs when the transfer is within the same plant Cross Pollination: occurs when the pollen of one plant is carried to the stigma of another by wind, water, air or other animals

Why Sex? There are advantages and disadvantages to the two reproductive strategies we have seen: Asexual Reproduction: Advantages? Disadvantages? Sexual Reproduction:

Read Text book Pages 27-34 Pg. 30 #1-4 Pg. 34 # 1, 3, 6, 8, 9, 11 Now Your Turn Science 9: Read Text book Pages 27-34 Pg. 30 #1-4 Pg. 34 # 1, 3, 6, 8, 9, 11