Sexual Reproduction

The key to genetic diversity!

SEXUAL REPRODUCTION

ReviewGive me an example of an inherited trait? What makes it an inherited trait? Give me an example of an acquired trait?What makes it an acquired trait?

Sexual Reproduction•Sexual means “to cross.” Sexual reproduction means that two parents combine parts of their genetic material. With sexual reproduction there is usually a male XY and a female XX.

Sexual Reproduction•The male contributes a copy of half of his genetic material and the female contributes a copy of half of her genetic material. The “baby” that is born is called the offspring. In a very basic way, offspring get half of their traits from each parent.

Sexual Reproduction•Because of the way the male and female copy their own genetic material and the way they are combined each offspring is different. It is a little like rolling dice for each offspring.

Meiosis• Through a process called meiosis, chromosomes are split apart into four separate cells that produce gametes. Each gamete contains different genetic information.

4 gametes

Reproduction: Crossing of Chromosomes

• Each parent contributes one gamete or chromosome set that is crossed to create an offspring or child. Since each chromosome set is different genetically, each child in a family is different. However, if two children have the same parents they will have similar traits and looks, since the genetic material came from the same parents.

Reinforcement• The child receives exactly half of its genetic information from the mother and exactly half from the father.

Offspring

gamete gamete

Sexual Reproduction in Plants• Plant have specialized anatomical parts to help them with sexual reproduction.• http://www.youtube.com/watch?v=FsBQQDg5GIw

Male Reproductive Anatomy in Plants• stamen-The male reproductive part on a flower• anther- The part of the stamen that contains pollen.• pollen- Tiny particles in plants that contain the male reproductive

genes.

• filaments- The part of the stamen that holds up the anther.

filament

anther

pollen

Pollen Grains

Female Reproductive Anatomy in Plants• pistil- The female reproductive part of a flower.• stigma-The receptive apex of the pistil of a flower, on which

pollen is deposited at pollination.• style-The usually slender part of a pistil, situated between the

ovary and the stigma.• ovary- A flower structure that encloses and protects the ovules

and seeds as they develop• ovule- A plant structure the houses female genetic information.

OvaryStyle

Stigma Pistil

Plant Fertilization• Pollen from the male anther is transported by wind, insects, bugs, and other means to the stigma of the pistil. The male genetic information is passed down the style into the ovary through a pollen tube where the male genetic material is crossed with the female genetic material in the ovule producing new offspring in the form of a seed. Plants ensure that they do not self-pollinate by special chemicals that recognize their own pollen and destroys it.

New Offspring (seed)

Species that use Sexual Reproduction

Mallard Ducks Salmon

FishChipmunks

Gecko Lizard Honey Bee

Seal

Species that use Sexual Reproduction

Petunias

Lilies Beetles

Lions Mule Deer Toads

Dissection of A Lily Flower•Instructions:•Draw and label the different structures of the Lily Flower as you see them on the overhead from the camera. •Label each of the structures with the correct term.

Review of Sexual Reproduction•How many different donors of chromosomes and genes are required for sexual reproduction?•What percentage of chromosomes and genes does an offspring receive from their father?•What part of the plant contains the male reproductive structures?•What part of the plant contains the male reproductive genes?•What part of the plant contains the female reproductive genes?•Name three living species that use sexual reproduction?

Quiz•Instructions:Match the correct flower structure to the correct definition. Hand it in before you leave.

Resources•http://www.neok12.com•http://www.uen.org/core/science/sciber/sciber7/stand-4/numparent.shtml