Recall: All Living Things Share Certain Characteristics -living things are highly organized -living things obtain and use energy -living things grow and develop -living things respond to stimuli -living things maintain a constant internal

environment (homeostasis) -living things are adapted to their

environments

Other Characteristics Shared -living things are made up of cells

Cell Theory: - All living things are made up of one or more

cells. - Cells are the basic unit of structure and

function in all living things. - All cells are produced from other cells.

-living things reproduce

How do cells make new cells?

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?

Answer: Mitosis

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.

It is the one characteristic that is not needed for the individual but for the Species.

Two types of Reproduction Asexual Sexual

Two parents Genetically different

What is Asexual Reproduction? Only one parent is involved. Offspring are genetically identical

to their parents. All cells that come from a single

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

Types of Asexual Reproduction

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

Types of Asexual Reproduction

2. Binary Fission - occurs in one-celled organisms such as the ameba and paramecium. The nucleus divides by mitosis and the cytoplasm divides, forming 2 new daughter cells of equal size.

Types of Asexual Reproduction

3. Budding - Occurs in Hydra (jelly fish) and yeast. The division of cytoplasm is unequal so one of the daughter cells is larger than the other. The daughter cells can separate or remain attached.

Types of Asexual Reproduction

4. Sporulation - occurs in molds, mushrooms, etc

Spores are produced in large numbers by mitosis.

Spores are surrounded by a tough coat to help them survive harsh environmental conditions.

Types of Asexual Reproduction

5.Regeneration - Refers to the replacement or regrowth of lost or damaged body parts, usually in invertebrates (no backbone) exception are lizards.

Types of Asexual Reproduction

6.Vegetative Propagation –

Occurs only in plants. New plants develop from the roots, stems, or leaves of the parent plant. Methods include: Runners, Tubers, bulbs, grafting

Types of Asexual Reproduction..cloning

All organisms that reproduce asexually are clones because they are genetically identical

However; we have learned how to clone from organisms that normally produce sexually…what is this?

Dolly The Cloned Sheep

Types of Asexual Reproduction..cloning

Types of Asexual Reproduction..cloningWhat are the benefits?

1.Plants and animals with desirable qualities can be produced from the cells of a single organism.

2.Perhaps help with growing more food.

3.Help endangered species repopulate

Types of Asexual Reproduction..cloningWhat are the problems?

1.There is an ethical problem for many people.

2.Since clones have identical DNA if there is a “problem” with one, there will be with all. (this is a disadvantage of asexual reproduction)

3.Though the DNA is exact (genotype) we know the environment at times “triggers” different genes…so the adult may not be the same phenotype.