Asexual Reproduction

-Production of offspring from one parent

-Involves mitosis

Mitosis – Cell Division

- exact duplication of all the chromosomes (# and information) in the nucleus, then separated into 2 identical sets.

- occurs in all cells except sex cells

Cancer – abnormal mitosis

Structure of a double-stranded chromosome

Chromatid – strand of a chromosome

Chromatin – material of a chromatid

Centromere – holds strands together

Gene – bands of information on chromosome (DNA)

Differences in Mitosis between Animal and Plant Cells

Animal Cells

- have centrioles

- cleavage (cell membrane pinches in – cytokenisis)

Plant Cells

- no centrioles

- no cleavage – cell plate forms (cell wall)

Animal cell mitosis – cleavage – pinching in

Plant cell mitosis – cell plate formation

Result of Mitosis:

- 2 identical cells made with the exact chromosome # and information as

parent cell – exact replicas.

Methods of Asexual Reproduction

-some organisms reproduce asexually (one parent) using the process of

mitosis.

1. Binary Fission:

- equal division of the cytoplasm of the organism. Ex. Ameba, Paramecium

- One organism splits itself equally and produces 2 new organisms.

Binary Fission

Paramecium Ameba

2. Budding:

- unequal division of the cytoplasm (not chromosomes!!!!!) Ex. Hydra and Yeast

Hydra

Yeast

3. Sporulation:

- multicellular organisms

- spores are released and develop new individuals

Bread Mold

4. Regeneration:

- invertebrates – undifferentiated cells (similar)

- development of entire new organism from part of original. Ex. Starfish, planaria

- replacement of lost structure.

Ex. Lobster clawPlanaria Starfish

5. Vegetative Propagation:

- Asexual Reproduction in Plants (mitosis)

- New plants develop from roots, stems and leaves of parent plant.

Natural: bulbs, tubers, runners

Natural

A. Bulbs – enlarged underground stem

ex. Onion, garlic, tulip

B. Tubers – enlarged underground stem with buds (eyes) ex. Potato

C. Runners – stem that runs along the ground. Ex. strawberries

Artificial:

a. cutting – stem or leaf is placed in soil and a new plant develops. Ex. Geranium

b. Grafting:

- stem of one plant is attached to cut end of another.

- No Blending

- red rose bush grafted to yellow rose bush produces a plant with red and yellow roses.

Results of Asexual Reproduction

-offspring are genetically identical to parent

-Same hereditary material (# and information on chromosomes)

-Same characteristics

Cloning Can occur naturally or artificially

Artificial- Nuclear Transfer1. Scientists take a parent (body) cell nucleus

(DNA)2. Insert the nucleus into a donor egg cell (the

nucleus from the egg was removed)3. The egg is now implanted into a surrogate

female for development4. The clone will be genetically identical to the

organism that the parent cell nucleus came from