Reproduction Notes

LT.R.1-I can define sexual and asexual reproduction. Know the definitions of sexual and asexual reproduction. Sexual reproduction always has to include the combining of gametes from two parents. The offspring produced by asexual reproduction is almost always an exact genetic copy of the single adult parent. There are three main ways that asexual reproduction occurs: budding, spores, and mitosis.

In budding, a group of cells (called a bud) develops on part of the organism and eventually grows into a new individual. Budding occurs in simple animals, like coral. Fungi and mosses can make spores, which get carried away and grow into new organisms. Single celled organisms reproduce by a form of mitosis.

LT.R.2-I can explain the importance of mitosis and meiosis in reproduction. Mitosis occurs in single celled organisms as a form of asexual reproduction, but it also occurs in multicellular organisms. In multicellular organisms mitosis is used to grow and develop new cells, like muscle cells. Draw the diagram of mitosis.

Meiosis is important to sexual reproduction because it is what allows sexual reproduction to take place. Without meiosis sexual reproduction would not produce offspring that were the same species or offspring that would even function. Meiosis is the process that produces gametes.

Meiosis is a two step process that produces sperm cells in males and egg cells in females. These gametes have only ½ the chromosomes of the organism they come from. They have 1 copy of each chromosome instead of 2. This is what allows organisms to produces offspring with the same number of chromosomes as the parents in sexual reproduction. This is why you get ½ your chromosomes from your dad and ½ from your mom. Draw the diagram of meiosis.

LT.R.4-I can compare the advantages and disadvantages of sexual and asexual reproduction. AdvantagesDisadvantages Sexual Reproduction Almost no individuals of a species are the same Very high survival rates in most species Population more resilient to changes in environment and disease Slow process Requires lots of energy at cellular level 1 to a few offspring at a time/slow population growth Asexual Reproduction Very fast process Requires little to no energy Able to quickly reproduce and make a large population quickly All individuals of the species are virtually identical High mortality rate in offspring Population more susceptible to widespread disease deaths and environment change deaths