Reproduction

DNA Molecule

Sex Chromosomes

Male embryos usually have an X and a Y chromosome in every cell, whereas females have two Xs in every cell.

When a human egg (from the mother) is fertilized by a sperm (from the father), together they form an embryo. The egg and sperm cells each contain a half-set of chromosomes – so the embryo comes to inherit a full set of chromosomes containing all the genetic instructions required for life, half from the mother, half from the father. A person’s chromosomal profile is called their karyotype.

One particularly important pair of chromosomes is the sex chromosomes which, as the name implies, determine the sex of the embryo. The sex chromosomes are the X chromosome and the Y chromosome. An oocyte (egg cell) from the mother almost always carries a single X chromosome, while a sperm cell from the father typically carries either an X or a Y chromosome (but not both). Depending on which type of sperm cell fertilises the egg, an embryo with two X chromosomes (that is, a sex chromosome karyotype of XX) or one X and one Y (XY) normally results. XX embryos usually develop as female, and XY embryos usually develop as males.

Chromosomes

Embryos

DNA

male

female

Egg & Seed

Plants

Chicken

Fish

Humans

Plants

Humans & other Mammals Reproduce Internally

HUMAN REPRODUCTION TERMINOLOGY

Genes – is the basic physical and functional unit of heredity. Genes, which are made up of DNA, act as instructions to make molecules called proteins.

You share 50% of each of your parent’s genes.

Offspring – is the product of reproduction. 

A human’s offspring is children.

A bear’s offspring is a cub.

A cow’s offspring is a cafe.

a cat’s offspring is a kitten

a dog’s offspring is a puppy etc…

Sexual Reproduction – when a male and female cell come together to create a unique organism.

Sperm – male reproductive cell – 50% of the father’s gene

Egg – female reproductive cell – 50% of the mother’s gene

Fertilization – joining of reproductive cells; two cells join together and the genetic material combines

Types of Fertilization – Internal & External

Internal Fertilization – Egg is fertilized inside of the body

Example:

A Human’s egg is fertilized inside the body of the woman

External Fertilization – Egg is fertilized outside of the body

Example:

Fish fertilize their eggs outside their bodies

SIDE VIEW OF THE MALE & FEMALE REPRODUCTIVE SYSTEM

INSIDE THE MALE & FEMALE REPRODUCTIVE SYSTEM: Reproductive organs

MALE REPRODUCTIVE ORGAN

FEMALE REPRODUCTIVE ORGAN

Male and Female Parts Join Together in the Process of Human Reproduction