The Cell Cycle Part 3

Asexual Reproduction

Science 9

Name ______________________

Date__________________

Mitosis is how cells divide• We just learned about the cell cycle and mitosis

• Cells use mitosis and cytokinesis to divide • Divide to replace dying out cells

• Divide to help an organism grow and develop

• Now we will learn how simple organisms (living things) reproduce to re-populate their species• Remember an organism can very small and only one cell big =

unicellular organism

• An organism can be made out of many cells = multicellular organisms

• Which type are we?

• Let’s learn how very simple organisms reproduce by learning different methods of Asexual reproduction

Multicellular

Asexual Reproduction

•Requires only ONE parent•The formation of a new individual that

has the same genetic information as its parent •This method of reproduction produces

a genetic clone of the parentEx) Dolly the Sheep

*Note: Humans DO NOTReproduce Asexually!

5 Methods of Asexual Reproduction1) Binary Fission• Used by unicellular organisms to reproduce

• Involves the splitting of a single parent cell into two equal parts

Ex) some bacteria, amoeba

1 celled organism, approx 1 mm

Fresh water, salt water, wet soil and animals

Algae, bacteria, plant cells, and can be parasitic

This looks similar to mitosis!

One cell copies its DNA and splits into two.

But bacteria are prokaryotic -no organelles-no nucleus

So it’s not the exact same thing as mitosis.

5 Methods of Asexual Reproduction

2) Budding

• a group of rapidly dividing cells develops on the parent organism, this is called a “bud”

• then the bud breaks off of the parent and the cells grow into an individual organism (copy of it’s parent)

Ex) sponges

and yeast

3) Fragmentation

• a small piece of an organism (parent) breaks away from it and develops into a new individual

ex) mosses, sea stars

5 Methods of Asexual Reproduction

4) Spore Formation

• parent organism produces spores : single cells that develop into new individuals after repeated mitosis

• Spores are released from the parent and will then use mitosis to grow and develop

ex) fungi, some algae

5 Methods of Asexual Reproduction

5) Vegetative Reproduction

• special cells in the stems and roots of plants divide repeatedly (undergo mitosis) to form structures that develop into a plant

• The new plant grows off of the pre-existing parent

Ex) most plants

5 Methods of Asexual Reproduction

Think, Pair, Share….

• In your opinion, why would organisms benefit from reproducing asexually?

• What do you suppose would be 2 disadvantages to asexual reproduction?

Pros/Cons of Asexual Reproduction• Use Table 5.1 on page 175 of BC Science 9 Textbook to

make a list of each…..Advantages of Asexual Reproduction Disadvantages of Asexual Reproduction

Human-Assisted Methods of Vegetative Reproduction

Read pages 173-174 of BC Science 9 Textbook

1) What is the cutting method?

2) What is grafting?

3) What are the advantages of grafting?

Stem Cells & Types of Cloning

BC Science 9 Textbook Pgs 176-178

1) What are stem cells?

2) Describe the difference between:

Reproductive Cloning Vs. Therapeutic Cloning