Sexual and Asexual Reproduction

Sexual reproduction is when two parents pass on genes to the offspring. The reproduction results in genetic diversity.

Sexual reproduction involves the fusing of two gametes.

Gametes are sex cells, the sperm and the egg.

The gametes carry genes, this means that an offspring will get half

of each parents genes.

In humans, a sperm cell with 23 chromosomes fuses with an egg cell with 23 chromosomes to produce a zygote with 46 chromosomes.

Zygote is a fertilized egg.

DNA or genetic make-up can only be inherited through the sex cells.

Many plants reproduce sexually. Flowers are the reproductive structures for the flowering plants.

They have both male and female structures that are involved in producing seeds

Flowering plants rely on insects, birds and the wind to assist with pollination

Stamen (male) surrounding the pistil (female)

Pollen from the anther moves down the pistil where it fertilizes the ovum and produces seeds

Asexual reproduction requires only one parent.

The offspring are genetically identical.

Types of Asexual Reproduction

Regeneration uses cell division to re-grow body parts (star fish) Budding a new organism grows from the body of the parent (potatoes)Binary Fission is a separation of the body into two new bodies, an organism duplicates its genetic material and then divides into two parts with each new organism receiving one copy of DNA (bacteria)

Genetics

Who was Gregor Mendel? Austrian monk who studied

mathematics and science As a boy he could predict the

possible types of flowers and fruits that would result from crossbreeding two plants in his father’s garden

Who was Gregor Mendel? Curiosity about the connection

between the color of a pea flower and the type of seed that same plant produced inspired him to begin experimenting with garden peas in 1856.

Made careful use of scientific methods, which resulted in the first recorded study of how traits pass from one generation to the next.

What is GENETICS?The study of how traits are

inherited through the interactions of genes.

What is a GENE? The material that controls

which traits are expressed in an organism

Genes come in pairs and offspring inherit one copy of each gene from each parent

It is a segment of DNA located on each chromosomes in the nucleus.

HEREDITYThe passing of traits from

parent to offspring

List the 3 Principles of Heredity

Traits are controlled by alleles on chromosomes

An allele’s effect is dominant or recessive

When a pair of chromosomes separate during meiosis the different alleles for a trait move into separate sex cells

ALLELE The different forms of a

trait that a gene may have

TRAIT Ways of looking,

thinking, or being Traits that are genetic

are passed down through the genes from parents to offspring

RECESSIVE A trait that is covered over, or dominated, by another form of that trait and seems to disappear

Hidden when the other copy of the gene contains the dominant allele.

A recessive allele shows up only when there is no dominant allele present

Shown with a lower-case letter

DOMINANT A trait that covers over,

or dominates, another form of that trait

Trait that always shows up, even when only one of the two alleles is in the dominant form

Shown by a capital letter

HOMOZYGOUS Both alleles [forms of the gene]

are the same When offspring inherit two

dominant genes, (one dominant gene from each parent) they are said to be homozygous dominant

When offspring inherit two recessive genes, (one recessive gene from each parent) they are said to be homozygous recessive

HETEROZYGOUS When alleles occur in different

forms When offspring inherit one

dominant gene and one recessive gene, they are said to be heterozygous

Since the dominant gene will be expressed, they are said to be heterozygous dominant

CO-DOMINANCE When an organism has two

different alleles for a gene that does not follow the dominant/recessive pattern

The organism shows a trait that is a blend of the traits represented by the two alleles

Also called INCOMPLETE DOMINANCE

GENOTYPEAn organism's genetic

makeup

PHENOTYPEOutward physical appearance and behavior of an organism