Reproductive Systems Reproduction Reproduction is the process through

Reproductive Systems

Reproduction • Reproduction is the process through which living things produce new individuals of the same kind. • Function: – essential for the continuation and survival of a species. • 2 Types: – Asexual Reproduction – Sexual Reproduction

Asexual Reproduction • Reproduction that required ONLY 1 parent. – Produces offspring are 100% identical to the parent. (4 chromosomes) (4 chromosomes each)

Types of Asexual Reproduction Fragmentation: A new organism can grow and develop from a fragment of the parent organism. Ex. Sea Star Budding: A daughter cell grows off of the parent organism and eventually falls off. Ex. Hydra Binary Fission: The parent organism is replaced by two daughter organisms. Ex. Bacteria

Pros & Cons • Pros (Advantages) – Faster reproductive rates. – Less complicated. – Less energy required. – Doesn’t require a second parent. • Cons (Disadvantages) – Decreases variation – Higher rates of extinction due to environmental changes.

Sexual Reproduction • Reproduction that requires 2 parents. – Produces offspring that are a 50/50 combination of both parents. (22 chromosomes) (44 chromosomes)

Pros & Cons • Pros (Advantages) – Genetic variation – Reduced rates of extinction. • Cons (Disadvantages) – Requires time and energy to search for a partner. – Slower reproductive rates. – Greater risk of mutations

Gametes • In sexual reproduction, each parent provides a different sex cell, gamete. – Male sex cell = sperm or pollen – Female sex cell = egg or seeds • Contains half the chromosome number of the whole organism. – Human = 46 chromosomes » Sex cells = 23 chromosomes each

Male Gametes • Pollen: flowering plants – Contained on the anther of the stamen. • Transported by wind, water, or organism. Sperm: mammals • Produced in the testes due to the hormone testosterone. • Transported in a liquid medium, semen.

Male Reproductive System Urinary Bladder Vas deferens Glands Urethra Testes

Male Reproductive System • Testes – produce sperm. Urinary Bladder – Enclosed in an external sac = scrotum • temperature regulator that ensures healthy production of sperm : – Too hot – lowers testes away from the body – Too cool – raises testes closer to the body Urethra Glands Testes Vas deferens

Male Reproductive System • Vas deferens – tube that connects the testes to the urethra. – glands release fluids, that provide nutrients and the liquid medium needed by the sperm to move through the female’s system – semen. Urinary Bladder Urethra Glands Testes Vas deferens

Male Reproductive System • Urethra - Semen, sperm and fluids, move down the urethra and out of the man’s body through the penis. Urinary Bladder Glands Urethra – Penis is the male sex organ. • What other body system is the urethra used in? Urinary System Testes Vas deferens

Male Sterilization 1. Castration - animals – – Permanent Testes are completely removed. 2. Vasectomy - humans – – Permanent Vas Deferens is tied off or cut. • Sperm can not travel past the separation.

Female Gametes Egg Cell: mammals • Produced in the ovaries due to the hormone estrogen. • Seeds: flowering plants – Contained in the ovary of the pistil. Seeds

Female Reproductive System Oviduct Uterus Ovary Cervix Vagina Uterine Lining

Female Reproductive System • Ovaries – produce egg cells, ova. Oviduct – A mature egg is released from an ovary - Ovulation. • Opposite sides each month. – At birth a female has her lifetime supply of eggs in her ovaries. Uterus Ovary Uterine Lining Cervix Vagina

Female Reproductive System • Oviduct – tube that connects the ovary to the uterus. – Cilia sweep the egg down the oviduct toward the uterus. – Fertilization takes place here! • An egg can only be fertilized for 24 hrs after ovulation and then begins to break down. Oviduct Uterus Ovary Cervix Uterine Lining Vagina

The Oviducts Oviduct abnormalities account for 25% to 50% of female infertility. Blocked tubes can alter the functioning of the oviducts making it so fertilization cannot take place, infertility. Healthy Blocked

Fertilization – Yes or No? Figure 1 • NO – Egg is in the oviduct. – No sperm present to fertilize the egg. – No fertilization! • Future Pregnancies? – Yes, if sperm and egg are both present.

Fertilization – Yes or No? Figure 2 • Yes – Egg is in the oviduct. – Sperm are present in the uterus. – Fertilization can take place.

Fertilization – Yes or No? Figure 3 • NO – Egg is in the ovary. – Sperm are present in the uterus. – Sperm cannot fertilize the egg until it is released into the oviduct. • Future Pregnancies? – Yes, if sperm and egg are both in the right location.

Fertilization – Yes or No? Figure 4 • NO – Egg is in the ovary. – Sperm are present in the uterus. – Both oviducts are blocked, sperm will never be able to fertilize the egg. • Future Pregnancies? – NEVER!

Female Reproductive System • Uterus - womb Oviduct – Pear-shaped – Muscular walls – Nutrient-rich lining • If the egg was not fertilized the nutrientrich lining begins to break down and leaves the body menstruation. Uterus Ovary Cervix Uterine Lining Vagina

Female Reproductive System • Cervix - Small muscular opening that separates the uterus from the vagina. Oviduct Uterus • Vagina – The birth canal. Ovary Cervix Uterine Lining Vagina

Female Birth Control Methods • Females have many more birth control options available then males: – Permanent 1. Tubal Ligation – cutting of the oviducts 2. Hysterectomy – removal of the uterus Tubal Ligation Hysterectomy

Female Birth Control Methods • Temporary 3. Birth Control Pill – 4. Intrauterine Device (IUD) – (There are many more methods but these are some of the most common!)