asexual and sexual reproduction subtitle: how new generations form

Asexual and Sexual Reproduction

Subtitle: how new generations form

Asexual Reproduction

Formation of new individuals from a single individual – one parent

Asexual Reproduction

There are several ways asexual reproduction can occur including:– Binary fission– Budding– Mitosis

• Primary form of reproduction for single celled organisms like bacteria.

• Many plants reproduce asexually as well.

• Asexual offspring (children) are identical to their parent.

Binary Fission

• In binary fission the parent organism is replaced by two daughter organisms, because it literally divides in two.

• Both prokaryotes and eukaryotes reproduce asexually through

binary fission

Prokaryotic vs. Eukaryotic

Budding• Some cells split by budding (for example

yeast), resulting in a 'mother' and 'daughter' cell.

• Potatoes, some flowers and spider plants reproduce by budding.– The offspring is smaller than the parent.

Mitosis

• Mitosis is a process of cell division which results in two daughter cells from a single parent cell.

• The daughter cells are identical to each other and to the parent cell.

• It is asexual reproduction.

Regeneration Process of renewal, restoration, and growth that

makes cells able to repair themselves after damage.

Regeneration

• Every species is capable of regeneration, from bacteria to humans.

• Starfish are able to re-grow arms if they have been cut off. Lizzards are able to re-grow tails.

Human Regeneration

All organisms, including humans, have the ability to regenerate something in the body. But the process is much more developed in lower organisms such as plants – mammals do regenerate skin, muscle, and blood. – other types of cells, such as those in the brain also

regenerate.

– researchers are actively working in this field to find ways to encourage the body to regenerate organs and limbs.

Sexual Reproduction

Creation of a new organism by combining the genetic material of

two organisms.

Sexual Reproduction

• Sexual reproduction is the process involving two parents. – Their genetic material is combined to produce

a new organism different from each parent.

• All mammals reproduce sexually. – Every person is unique. – Even brothers/sisters are often very different

from one another.

Fraternal Twins

• Fraternal twins make up approximately 75% of the twin population and can be boy/boy, girl/girl, or boy/girl sets. Happen when Mom releases two eggs and different sperm fertilize each egg.

• They do not look any more alike than typical siblings.

Maternal Twins

Occur when a single egg is fertilized which then divides into two separate embryos.

Chromosomes

• With sexual reproduction, the offspring inherits half their chromosomes from each parent. – Half the chromosomes means not all traits of

a parent will be transferred to the offspring. More on that in the next section on inherited traits!

Chromosomes

• Chromosomes are structures found within the nucleus of a cell.

• They contain all the genetic information in the form of genes.

DNA

• DNA is a long chain formation found in the nucleus of a cell.

• It is shaped like a double-helix

• It contains all the genetic material

Donor Cells for Sexual Reproduction

• Sperm are the reproductive cells of males.

• Eggs are the reproductive cells of females.– Sperm and egg cells are different from all

other cells in your body because they contain only half of your genetic information.

– 2 halves combine to make a whole new organism!

Meiosis

One cell from each parent contributes genetic material to produce offspring.

– Results in 2 daughter cells

– Receives ½ of genetic material from each parent

– Produces sex cells

– You were produced by Meiosis!

MeiosisIn the diagram, the parentcell duplicates it’s DNA thendivides. Will combine withanother parent to complete theProcess and each contributeHalf of the offspring’s DNA.