ASEXUAL & SEXUAL REPRODUCTION

REPRODUCTION PRODUCES NEW INDIVIDUALS OF A SPECIES.

The way a species reproduces determines how much variation the new individuals will have.

REPRODUCTION…

Can produce new individuals that are identical to or very different from one another.

Which produces greater variation in individual organisms… Asexual or Sexual Reproduction?

ASEXUAL REPRODUCTION

Involves only one parent.

All offspring that result from asexual reproduction are identical to that parent.

In other words, the adult makes an exact copy of itself.

There are several different forms of asexual reproduction.

1. BINARY FISSION

BINARY FISSION

Only 1 cell organisms, and some protists, such as amoebas and some algae, reproduce by binary fission.

During binary fission, a cell splits exactly in two, producing two identical individuals.

Binary = two

Fission = splitting or dividing (cleavage)

REMEMBER…

The Protista Kingdom consists of unicellular lifeforms (lifeforms with only one cell) who have a nucleus.

The primary difference between protists and monera (bacteria) is that protists are more complex, having a nucleus.

2. BUDDING

ORGANISMS…

Such as hydra and yeast reproduce asexually by budding.

During budding, the parent produces a small “bud”, or a smaller version of itself.

In most animals (like the hydra) and unicellular fungus (yeast), the bud detaches and becomes a new individual identical to its parent.

In some (such as coral) the offspring remains attached to the parent, forming a large structure composed of many identical individuals.

SPORE PRODUCTION

SPORES Similar to seeds, but are produced by the

division of cells of the parent, not by the union of two cells.

ONE INDIVIDUAL Will produce many spores, and each spore

can develop into a new individual identical to the parent.

Most fungi, green algae, some molds, and non-flowering plants, such as ferns, reproduce by producing spores.

4. VEGETATIVE REPRODUCTION

THERE ARE DIFFERENT FORMS OF VEGETATIVE REPRODUCTION

Vegetative reproduction is the reproduction of a plant that does not involve the formation of a seed.

Most plants can reproduce this way.

IF YOU TAKE A “CUTTING” FROM A PLANT…

And place it in water, the cutting will grow roots and eventually develop into a whole new plant.

Many plants, such as strawberries or spider plants, grow runners that produce new plants.

TUBERS… Such as potatoes on a potato plant, and

bulbs, from which tulips develop, are also forms of vegetative reproduction.

THE ROOTS OF AN ASPEN TREE…

Form a shoot called a “sucker”; if the sucker becomes separated from the original tree, it will grow into a new aspen tree.

IN ALL OF THESE FORMS OF VEGETATIVE REPRODUCTION…

The individual new plants that are produced will be genetically identical to their parent plant and to one another.