1

Asexual Reproduction

Purpose of Reproduction

□ To make sure a species can survive

and not become extinct.

- Definition: Reproduction is the

process by which an organism

produces others of its own kind.

2 Types of

Reproduction

Asexual Reproduction

Sexual

Reproduction

Involves mitoticcell division

Involves meioticcell division

Asexual

Reproduction

Sexual

Reproduction� Without sex

� Produce new offspring

� 1 parent organism

� No sperm or egg

(no gametes)

� Mitosis- mitotic cell division

(cells divide)

� Offspring- genetically

identical (clones)

� No genetic variations

(differences) in offspring

� With sex

� Produce new offspring

� 2 parents (male & female)

� Has sperm & egg

(gametes- sex cells)

� Meiosis- meiotic cell division

(sex cells made)

� Offspring- genetically

different than parents

�A lot of genetic variations in

offspring

Examples

1. Bacteria

2. Ameba

3. Yeast

4. Paramecium

5. Hydra

6. Fungus (bread mold,

mushroom)

7. Leaves, stems, roots of

plants

8. Body cells of

multicellular organisms

(skin cells)

1. Mammals (bears, lions,

deer, humans)

2. Flower part of plants

3. Fish

4.Reptiles

5. Birds

6. Amphibians (frog,

toad, salamander)

Asexual

ReproductionSexual

Reproduction

Bacteria

Ameba Hydra

Paramecium

Silver book reading pg. 137-138

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5 Types of Asexual Reproduction

1. Binary Fission

2. Budding

3. Spore Formation

4. Regeneration

5. Vegetative Reproduction

1. Binary Fission

� Parent cell divides into 2 equal parts called

daughter cells (smaller than parent).

� Parent cell no longer exists.

EX: Bacteria, Protozoa (ameba, paramecium)

1 Parent Cell

Nucleus divides

Cytoplasm divides

2 Daughter Cells

2. Budding

� Parent organism divides

into 2 unequal parts.

� Parent & offspring not the

same size.

�Offsprings may break off or remain attached

forming a colony (buds).

EX: Yeast, hydra

Can You Locate Budding?1.

2.

� Budding seen in plants.

3. Spore Formation

� Spores are single-celled structures.

� Formed within a single cell structure then released.

� Spores are the remains (left-overs) of the original parent cell.

� Environmental factors affect spore formation (light, oxygen, temperature, and nutrient availability).

EX: Fungi, alga, protozoa

3

Spore Wall Formation

Bread Mold

Spore Formation

(Sporulation)

Spores

� Spores

break down

and are carried

away by air

currents.

State how the genetic information in the nuclei of cells in bread mold B compare to the genetic information in the nuclei of cells in bread mold A.

1.

In the Paramecium, which is true of a daughter cell that results from fission?

(1.) It has one-half as many chromosomes as the parent cell. (2.) It has the same number of chromosomes as the parent cell and is the same size as the parent. (3.) It has twice as many chromosomes as the parent cell. (4.) It has as many chromosomes as the parent cell, but is smaller.

2.

� The ability to restore lost or damaged

tissues, organs, or limbs.

� Invertebrates

- worms - sponges- starfish - lobsters

- planarian - salamander

4. Regeneration Regeneration

PlanarianStarfish

4

Planarian

http://www.planarians.org/

Planarian attacking an earthworm

Stages of

Salamander

Regeneration

� The new plant is exactly the same as the parent plant.

� Important for nutrition and growth of plants.

� Involves roots, stems, and leaves.

EX: plants, seedless fruits and vegetables

5. Vegetative Reproduction

(Propagation)Identical to Parent Plant!

Parent

PlantNew

Plant

2 Types of Vegetative Reproduction

Natural

Bulb

Tuber

Runner

Rhizome

Artificial

Leaf

Cutting

Grafting

Natural Vegetative Reproduction

5

Vegetative Reproduction(Propagation)

□ “leaves, stems, or roots of plants

are used to form new plants”.

1. Bulbs

�Short undergroundstem with thick fleshy

leaves that contain stored food.

� Each bulb can develop into a new

plant.

EX: Onions, tulips, and lillies

Is Garlic a Bulb?

YES

It has axillary

buds that grow

to form many

offsets (cloves).

2. Tubers

� A large undergroundstem that contain stored

food.

EX: White potatoes

the “eyes” (tiny buds)

can develop into new

plants.

The “eyes” of potatoes

Tubers 3. Runner

�Stems grow over the surface of soil

from the existing stem.

�At points along the runners, new

plants grow.

EX: Strawberries,

grassesRunner

6

Runner 4. Rhizome�Long stems that grow horizontally

under the soil.

�New plants are produced at

nodes along the stem.

EX: Lawn grasses

ferns

irises

Rhizome Natural Vegetative Reproduction

Locate:

1. Rhizome

2. Runner

3. Daughter

plant

Answers:

Rhizome

Daughter plant

Runner

Daughterplant

ArtificialVegetative Reproduction

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1. Cutting (Stem and leaf)

� A human activity

� Pieces of roots, stems, or leaves are cut, placed in

water or moist soil to develop into new plants.

EX: Roses, sugar canes, bananas, ivy The development of roots

from part of a plant structure.

Cutting (Stem and leaf)

Kalanchoe

2. Grafting�A stem or bud is removed from 1 plant

and joined permanently to the stem of a closely related plant.

• Stock - the part containing the roots.

• Scion- is the added piece.

EX: Peach trees navel ________plum trees grapesMcIntosh ________, grapefruits

Grafting

Covered to prevent water loss.

3. Layering�When the stem is

bent over and part of it is covered withsoil.

EX: Black rasberry

blackberry plants.

Review

Asexual

Reproduction

8

Question: True or False

In Asexual Reproduction The Offspring Are Genetically Identical To The Parent?

True

Review: Identify each diagram with the

correct asexual reproduction process.

RunnerBudding

Binary Fission

A.

B.

C.

Sporulation Rhizome Budding

D. E. F.

Budding Grafting

Sporulation

G. H.

I.