Asexual vs. Sexual Reproduction Modified from: d/Corens/asexual_vs._sexual_reproduction.ppt d/Corens/asexual_vs._sexual_reproduction.ppt

Asexual reproduction A form of reproduction which does not involve meiosis or fertilization. Asexual reproduction = one parent. The primary form of reproduction for single- celled organisms such as archaea, bacteria, and protists. Many plants and fungi reproduce mostly asexually as well.

Sexual Reproduction Results in increasing genetic diversity of the offspring. Characterized by two processes: meiosis, halving of the number of chromosomes fertilization, combination of two gametes and the restoration of the original number of chromosomes During meiosis, chromosomes usually cross over = genetic recombination. Primary method of reproduction for the vast majority of visible organisms, including almost all animals and plants.

Binary Fission Asexual Cell splits and replicated DNA goes with each part Prokaryotes, Bacteria + Fast and easy - Everybody has the same DNA

Bacterial Conjugation Asexual, “Sexual” A bacteria shoots out a tube and sends a piece of its DNA to another bacteria Bacteria + Mixes DNA - “Parent” loses a little piece of DNA

Fragmentation/ regeneration Asexual Body of parent breaks and produces offspring Fungi, moss, sea stars, planarian + Easy - Parent broken, same DNA

Fragmentation/ regeneration Moss

Budding Asexual Offspring grows out of parent Yeast, hydras + Fast, somewhat easy - Same DNA

Spore Formation Spore Formation – spores = small specialized cells that contain a nucleus and cytoplasm surrounded by a thick outside wall which protects the spore. Under the right conditions the spore can rise to a new organism. Found in bacteria, molds, yeast, mushrooms, mosses, ferns and some protozoans.

Spore formation

Vegetative Reproduction

Bulb = Short underground stem surrounded by thick leaves. Contain stored food. As the plant grows it produces new bulbs which will grow into new plants. Tulips, onions, and lilies.

Tuber = enlarged part of an underground stem that contains stored food. Potatoes are tubers. “Eyes” = tiny buds that can form a new potato plant. How you plant potatoes. Great potato famine.

Runner or stolen = horizontal stem above the ground with buds. If a bud touches the ground it will form roots and stems and start a new plant. Strawberries.

Sexual Reproduction

Pollination Sexual Reproduction Pollen is delivered to female part of plant Flowering plants + Plants don’t have to move, mixes DNA - Need external source for pollination to take place; wind, bee, bat, butterfly etc.

Pollination

Sexual Reproduction DNA from 2 individuals merge to form one Animals, Plants + Diverse DNA - Takes a long time, 2 individuals needed

Sexual Reproduction