Chapter 4 Lesson 2 - Asexual Reproduction

Asexual reproduction

1 parent produces genetically identical offspring

Sexual reproduction

2 parents produce genetically unique offspring

Consider a bacteria cell that can divide once every hour. In 1 hour there would be 2 cells, in 2 hours there would be 4 cells, and in 3 hours there would be 8 cells. Now do the math! How many bacteria cells would there be in just 24 hours? (use a calculator).

6,777,216 bacteria cells in 24 hours (This is 2 to the 24th power. Ex. 22​ 4)

Describe Budding:

A new organism grows by mitosis and cell division on the body of its parent. The bud or offspring is genetically identical to its parent. When the bud becomes big enough, it can break from its parent and live on its own.

What do we call cell division in a prokaryotic cell?

Fission

Describe regeneration:

In regeneration, an offspring grows from a piece of its parent.

Using the example of crabgrass described in the book, explain why genetic variation is important to a population of organisms.

In the example of crabgrass, if a certain weed killer can kill the parent plant, then it can kill all the crabgrass plants in the lawn because they are genetically identical to the parent.

What was the first mammal to be cloned? What was her name?

a. A sheep named Dolly

Describe Cloning:

a. A type of asexual reproduction performed in a laboratory that produces identical individuals from a cell or from a cluster of cells taken from a multicellular organism.

What do all organisms produced by asexual reproduction (naturally or in a lab) have in common in terms of genetics?

a. All organisms/offspring produced by asexual reproduction are identical to each other and also identical to the parent.

List at least three similarities you can see between mitosis and binary fission (you will need to think back to what we just learned about mitosis).

a. DNA is copied. b. Cell elongates. c. Cell membrane pinches in the middle. d. Cell splits and two identical daughter cells are formed.

Explain how fission happens in a common bacterium such as ​E. coli:

a. DNA molecule is copied b. Each copy attaches to the cell membrane. c. Cell grows longer pulling the copies of DNA apart. d. Cell membrane pinches inward toward the middle of the cell. e. Cell splits and forms two identical daughter cells.

Give three reasons that the above method of cloning plants may be useful.

a. Desirable traits can be copied. b. A greater number of plants can be produced more quickly than by vegetative reproduction. c. It can be used to reproduce plants that have been infected with a disease.

List the six different types of asexual reproduction that the book describes:

a. Fission b. Mitotic Cell Division c. Budding d. Animal Regeneration e. Vegetative Reproduction f. Cloning

One of the disadvantages of asexual reproduction is that it produces populations that do not have much genetic variation. Explain what this means.

a. Genetic variation gives organisms a better chance of surviving if the environment changes. b. Mutations can occur. If this is a harmful mutation, it will be passed to asexually reproduced offspring.

Give two examples of eukaryotic cells that reproduce by budding.

a. Hydra b. Yeast

What are two advantages of asexual reproduction?

a. Organisms can reproduce without a mate. b. Organisms rapidly produce a large number of offspring.

Why is regeneration of a body part (i.e. a salamander growing a new tail) NOT considered asexual reproduction?

a. The part is replaced but a new organism is not produced.

Describe vegetative reproduction:

a. This is a form of asexual reproduction in which offspring grow from a part of a parent plant. This type of asexual reproduction involves structures such as roots, stems, and leaves of the plant.

What makes cloning different from the other types of asexual reproduction you just described?

a. This type of asexual reproduction is intentionally done in a laboratory to make copies of organisms with desirable traits.

List three organisms that can reproduce by regeneration.

a. sea stars, sea urchins, sea cucumbers b. sponges c. planarians

What type of organisms usually undergo vegetative reproduction?

a. strawberries, raspberries, potatoes, and geraniums

What is the method used to clone plants called?

tissue culture