Reproduction Introduction Asexual reproduction: 1. The prefix “A” comes from the Greek language and means without. 2.The term asexual means without to cross which really doesn’t make sense but it is also defined as without crossing. 3.Asexual organisms make an exact copy of themselves, like a photocopy. 4.Is there much variation (different genes) in a group of paramecia ? No. Paramecia offspring are all identical to the parent (cell that divides) genetically because there is no combination of traits or genes.

Reproduction Introduction Sexual reproduction: 1. Sexual reproduction means to “to cross”. 2.Sexual reproduction means that two parents combine parts of their genetic material (DNA).The male contributes a copy of half his genetic material and the female contributes a copy of half of her genetic material. 3.The “baby” that is born is called the offspring. 4.In a very basic way, the offspring get half their traits from each parent. 5.Because of the way the male and female copy their own genetic material and the way they are combined each offspring is different.

Circle the correct type of reproduction: 1. MammalSexual Asexual Both 2. InsectSexual Asexual Both 3. FishSexual Asexual Both 4. PlantsSexual Asexual Both 5. BacteriaSexual Asexual Both mixing DNA Reproduction Introduction

Types of Reproduction Sexual vs. Asexual Reproduction

Reproduction  In order to be considered alive, organisms must be able to reproduce  Reproduction is the ability to produce offspring that are similar to the parents.  Offspring - the product of reproduction. The “child” or “baby”.  There are two possible ways the organisms can reproduce:  Asexual reproduction  Sexual reproduction

Asexual Reproduction  Asexual reproduction: reproduction where an organism makes an exact copy of itself and splits to become two separate organisms  Asexual reproduction is characterized by:  Only 1 parent  Parent and offspring are identical genetic copies  Copying mistake (genetic mutations) can occur  A small, limited gene pool (little variation)  Requires less energy

Asexual reproducers:  Bacteria  Hydra (simple sea animals)  Microscopic organisms (paramecium, amoeba)

Types of Asexual Reproduction Budding Fragmentation Propagation Regeneration Binary Fission Others…

Budding Process by which a new, duplicate plant or animal begins to form at the side of the parent and enlarges until an individual is created. Common in some plants and hydra

Fragmentation In this type of reproduction, the body of the parent breaks into distinct pieces, each of which can produce an offspring. Common in some types worms like Planaria

Propagation Part of the parent cell is cut off and can grow into a new individual. Common in certain plants.

Regeneration If a piece of a parent is detached, it can grow and develop into a completely new individual. It is a common feature in invertebrates like starfish.

Binary Fission Separation of one organism into two new organisms by mitosis. Only in single celled organisms like bacteria and protists.

Sexual Reproduction  Sexual reproduction: reproduction where two organisms’ genetic information (DNA) combines in a single, new offspring  Sexual reproduction is characterized by:  Two parents (male and female)  Combination of egg and sperm cells  Genetic information gets mixed  Large gene pool (lots of variation in traits)

Sexual reproducers  Mammals, Fish, Reptiles, Birds,  Most Insects  Most Plants  Large, complex organisms

BOTH Asexual and Sexual Reproduction Some organisms can use both types of reproduction. There are advantages to each method. Most organism switch to the type of reproduction that is best for their current situation. Examples: –organisms that can regenerate - star fish, newts, worms –Some plants – Daffodil, Cactus –Fungi – Mushrooms

Advantages and Disadvantages of Asexual Reproduction ADVANTAGES Less energy required Don’t need to find a partner Very Quick (Have several offspring in a short amount of time) Less resources required DISADVANTAGES Need a stable environment Sensitive to their environment Limited amount of traits available No mixing of DNA

Advantages and Disadvantages of Sexual Reproduction ADVANTAGES Don’t need a stable environment Varied genetically (Many traits to choose from) Mixing of DNA; endless possibilities of traits. DISADVANTAGES Need to find a partner Requires more energy Smaller amount of offspring More resources needed.