Sexual vs. Asexual Reproduction Mitosis & Meiosis

Essential Questions What is the difference between sexual and asexual reproduction? (Mitosis & Meiosis) What is the difference between sexual and asexual reproduction? (Mitosis & Meiosis) What types of organisms produce sexually? Asexually? What types of organisms produce sexually? Asexually? What are the advantages and disadvantages to each type of reproduction? What are the advantages and disadvantages to each type of reproduction?

Mitosis Mitosis is used for: Mitosis is used for: Growth Growth Cell Replacement Cell Replacement Regeneration Regeneration Asexual Reproduction Asexual Reproduction

Mitosis The process of mitosis occurs when a cell copies its genetic information once and then divides once. The process of mitosis occurs when a cell copies its genetic information once and then divides once. For example: When human skin cell undergo mitosis they start with 46 chromosomes, those chromosomes make a copy of themselves, then the cell divides, giving each of the new cells a copy. For example: When human skin cell undergo mitosis they start with 46 chromosomes, those chromosomes make a copy of themselves, then the cell divides, giving each of the new cells a copy. The result is two identical cells with 46 chromosomes each. The result is two identical cells with 46 chromosomes each.

Some animals reproduce by mitosis. Asexual Reproduction

Hydra (Budding) The hydra is a tiny water animal that usually begins life as a bud that grows on the body of its parent. When fully developed, the young hydra detaches itself and lives independently.

Bacteria (Fission) Streptococcus Anthrax Escherichia coli (E.coli)

Planaria (Regeneration) Planarians normally reproduce by pulling in two. The fragments then regenerate their missing parts.

Sea Stars

Strawberries (tubers) Houseplants (cuttings)

Advantages or Disadvantage? Only one parent is needed so the organism can reproduce at anytime. Only one parent is needed so the organism can reproduce at anytime. Because there is only one “parent” there is no genetic variation. The “child” is an exact duplicate. Because there is only one “parent” there is no genetic variation. The “child” is an exact duplicate.

Sexual Reproduction This occurs when two parent cells come together to form a new organism (zygote). This occurs when two parent cells come together to form a new organism (zygote). The parent cells often called sex cells (eggs and sperm) are formed in a process called meiosis. The parent cells often called sex cells (eggs and sperm) are formed in a process called meiosis.

Meiosis When meiosis occurs the genetic information is copied once and the cell divides twice. Each new gamete cell contains only one-half of the number of chromosomes of the parent cell. In humans the result is 4 sex cells each with 23 chromosomes rather than the usual 46.

Sexual Reproduction When the egg and the sperm unite they form a new organism called a zygote. When the egg and the sperm unite they form a new organism called a zygote. In humans the offspring inherits 23 chromosomes from the mother and 23 chromosomes from the father thus giving them a full set of 46 chromosomes. In humans the offspring inherits 23 chromosomes from the mother and 23 chromosomes from the father thus giving them a full set of 46 chromosomes. The offspring therefore has characteristics of both parents. The offspring therefore has characteristics of both parents.

Advantage or Disadvantage? Sexual reproduction results in greater genetic variation. Sexual reproduction results in greater genetic variation. Genetic variation is very beneficial in the process of natural selection. Genetic variation is very beneficial in the process of natural selection. Sexual reproduction does require two parents. Sexual reproduction does require two parents.

Organisms that reproduce Sexually LionsDogsRabbitsMosquitoesSunflowersSalmonPeople

How many organisms are needed for asexual reproduction? 1

What is the end result of mitosis? 2 identical daughter cells

What are the different uses for mitosis? New cells, growth and development, reproduction

What are some examples of organisms that reproduce asexually?

How many times is the genetic information copied in Meiosis? 1

How many times does the cell divide in meiosis? 2

What is the end result of Meiosis? 4 cells with half as many chromosomes.

Once the sperm fertilizes the egg in a human how many chromosomes are present in the zygote? 23+23=46

After fertilization what process allows the zygote to grow into a baby? Mitosis