Sexual vs Asexual Reproduction Mode of Reproduction 6.12D.

Sexual vs Asexual Reproduction

Mode of Reproduction6.12D

Students will…

• Identify examples of asexual and sexual reproduction

• Recognize that asexual reproduction results in more uniform offspring

• Realize that sexual reproduction results in more diverse offspring

(offspring = babies, young, children)

Purpose of Reproduction

• One of the characteristics of all living things is the ability to reproduce.

• During reproduction, organisms make more of their own kind.

• The purpose of reproduction is to make sure the species continues to live on

Young have characteristics in common with the adults

• Reproduction is the process by which an organism produces others of its kind.

Offspring

• Offspring are the products of reproduction.

ASEXUAL REPRODUCTION

Asexual Reproduction

• A new organism is produced from a single organism

• The offspring will have identical genetic information to the parent organism

• Simple form of reproduction that occurs in more basic organismsEach bud on this cactuscan grow into a new plant identical to the parent.

Types of Asexual Reproduction

•Binary fission•Budding •Regeneration

Binary Fission

• The simplest method of reproduction• A ‘mother cell’ splits into two identical

‘daughter cells.’• The results offer no variation• Often occurs in organisms such as bacteria or

protozoans

Examples of binary fission

Budding

• Budding occurs when a bulge grows on the side of the parent organism and eventually breaks off to become a separate organism.

• Often occurs in plants.

Budding

Regeneration

• Regeneration is the ability to re-grow lost or damaged tissues or organs.

• This occurs commonly in some invertebrates such as starfish and worms.

• If an entirely new organism can be grown from a piece of the parent organism, then it is considered a form of asexual reproduction.

Examples of regeneration

This starfish is re-growing 3 of its arms. A starfish has remarkable regeneration abilities.Oyster collectors used to cut up starfish thinking they had killed them.In reality, each piece of the starfish that contained a part of the central disc was able to grow into a whole new organism.

Lizard Tails

These lizards have lost their tails which will grow back through the process of regeneration.However, since the tail cannot grow a new lizard, this regeneration is not a form of asexual reproduction.

Review of Asexual Reproduction

• Requires only one parent• Only one set of genetic material is involved• No mixing of genes• Produces offspring that are identical to the

parent • Offspring have the identical genetic

information as the parent so no variety is produced

SEXUAL REPRODUCTION

Sexual reproduction

• Requires a male cell and a female cell • Requires two parents and two sets of genetic material• Offspring receive a combination of genetic material• Results in variety• More complex form of reproduction• Occurs in most animals• Also occurs in many plants (seeds contain genetic

material from an egg cell that is fertilized by a sperm cell)

Sexual reproduction requires male and female sex cells.

Offspring receive genetic information from 2 parents

Results in variety!

Review

• Asexual reproduction results in offspring that are genetically identical to the single parent.

• Sexual reproduction combines genetic information from two parents and results in a new combination of genetic material that is different from mother or father.

• Simpler organisms reproduce asexually• More complex organisms use sexual reproduction• Plants often use both asexual (budding) and sexual

(flowering) reproduction.

Summary of differences between asexual and sexual reproduction

Number of parents

1 2 (one male, one female)

Make up of offspring

Genetically identical toparent and other offspring

Genetically unique

Advantages Rapid reproduction – quicklybuilds population numbers

Produces more variation

Disadvantages Disease or other conditionsmay kill off the entire population

Slower process

By Kingdoms

• Bacteria and Archae – Reproduce asexually • Protists – both sexual and asexual

reproduction• Fungi – both sexual and asexual reproduction• Plants – both sexual and asexual reproduction• Animals – usually sexual reproduction

Question for discussion