How do cells make new cells?

Do You know: What happens when you cut a worm

in half?Why do you think you can grow new

skin over a cut on you hand but you can’t grow new fingers?

What is reproduction?

Reproduction is the process by which organisms produce more of their own kind.

• Think about it – Without reproduction, all life on earth would no longer exist.

What is Asexual Reproduction?

• Only one parent is involved.• Offspring are genetically identical

to their parents.• Creates no genetic variation.• All cells that come from a single cell

are genetically identical to it and to each other; they are all clones.

1.1. MitosisMitosis - is the exact duplication of the nucleus of a cell so as to form two identical nuclei during cell division.

2. It occurs in somatic cells (body cells). Function is for growth and repair of tissue.

Types of Division during Asexual Reproduction

Parent divides to form two new daughter cells

2.2.Binary FissionBinary Fission –

Many, but not all, single-celled organisms (unicellular), such as bacteria, and protists, reproduce asexually through binary fission.

Types of division during Asexual Reproduction

Such Protists include, amoeba’s and paramecium.The nucleus divides by binary fission and the cytoplasm divides, forming 2 new cells of equal size.

Binary Fission

Amoebas reproduce asexually by binary fission. A parent cell divides (the nucleus also divides in a process called fission)

and produces two identical copies of itself.

Bacteria dividing by binary fission

3.3.BuddingBuddingSome cells split via budding (for example baker's yeast), a. The buds grow into fully

matured individuals which eventually break away from the parent animal

Types of Asexual Reproduction

• Seen Mostly in Marine Animals and Yeast– Examples Include; Sponges, Corals and

Jellyfish…

Some starfish can reproduce sexually and asexually. The starfish below has legs that are uneven because they have broken off in the process of asexual

reproduction.

YouTube - Sea Star Regeneration

• Watch the video clip to see starfish regeneration.

• This shows 2 new limbs starting to bud.

• The old limbs that fell off will regenerate into 2 new starfish genetically identical to the parent.

Budding in Hydra

The video link below will show a hydra in the process of budding.YouTube - Hydra

4.4. Vegetative PropagationVegetative Propagation – found in plants where new independent individuals are formed without the production of seeds or spores

Example – fragmentation, where small fragments of the plant develop into a new plant

Types of Asexual Reproduction

Iris Rhizomes (roots) can be cut and a new plant will grow.

Spider plants send out runners that can cut be planted. The new plant is a clone of the parent.

Adult Plant Detached Runners