Types of Reproduction Chapter 3.3

Reproduction The passing of genes from a parent generation onto their offspring Passing on genes ensures the continuation of a species Without reproduction, a species will go extinct 2 Types Asexual Sexual

Asexual Reproduction Requires only one parent Offspring have 100% the same chromosomes as the parent Offspring are “clones” No new variation of traits Most common in unicellular organisms Cells make copies of themselves Mitosis

Examples of Asexual Reproduction Binary Fission Budding Fragmentation/Regeneration

Binary Fission Occurs in prokaryotes Reproduction by dividing in half Bacteria

Budding Both unicellular and multicellular Offspring grows off the body of the parent Parent produces tiny buds When a bud reaches a certain size, it breaks free of the parent Yeast, Hydra, cactus

Fragmentation/Regeneration Multicellular organisms Parent breaks into pieces which become the offspring Starfish, corals, plant cuttings

Asexual Reproduction and Health Generation time of many bacteria is very short The time it takes for one generation to produce offspring (the next generation) Some types of bacteria can produce a new generation in less than 30 minutes!

Sexual Reproduction Two different parents Requires production of special sex cells called gametes produced through meiosis Egg (Ovum) cells Sperm cells Fertilization is when egg and sperm combine Egg + Sperm = Zygote (First cells of a new organism)

Sexual Reproduction Most multicellular organisms undergo sexual reproduction Provides genetic variation (offspring are genetically different from their parents) Each gamete has different combination of parent’s genes Fertilization brings together separate genetic material of 2 different parents

Summary Asexual Reproduction Sexual Reproduction

Summary Asexual Reproduction Sexual Reproduction A. No mixing of genes only _________ parent. A. Mixing of genes from _________ parents B. Offspring are ____________________ to the parent— called clones B. Offspring are genetically______________________ , but not __________________________ to either parent Best form of reproduction in a ______________________________ environment There is little need for genetic diversity in the population because organisms are well suited to their environment. C. Advantageous in a ___________________________________ environment There is need for more genetic diversity so some individuals are likely to survive an environmental change. D. Typical in most __________________________ organisms and some multicellular like hydra, jellyfish, some plants D. Most ____________________________ organisms

Investigating Reproductive Strategies Your group will be split in two. One half will investigate asexual reproduction and the other half sexual reproduction. Travel to all 3 organisms stations for your type of reproduction. Then, groups will reconvene and share information.

Investigating Reproductive Strategies Travel to the last stations you need to complete. Original table groups will reconvene. Share information so all members have info for both asexual and sexual reproduction.