BIO 102 - Chapter 35 - Animal Reproduction and Development

Asexual Reproduction

Asexual Reproduction

Reproduction that does not require a partner and produces identical or nearly identical offspring. Ex. Bacteria

Sexual Reproduction

Both parents contribute genes to the offspring, which are genetically unique.

Gametes

The gonads of sexual reproducing individuals produce haploid gametes. Ex. Eggs and Sperm

Zygote

Result of fertilization, formed when sperm and egg fuse. It is the earliest stage of a new organism's development.

External Fertilization

When a sperm cell unites with an egg cell released from a female.

Ex. Sea Urchin, Fish

Internal Fertilization

When gametes unite inside the body of the parent

Differentiate

To acquire specialized functions

Pattern formation

The process used to determine the overall shape and structure of an animal’s body.

Direct Development

Process of development where the final product is built in a single step without any intermediate versions or iterations. The growth of a person

Indirect Development

Process of growth and development in which an organism undergoes a series of distinct stages with significant morphological changes before reaching the adult form. Ex. Metamorphis of Butterfly

Testes

Male reproductive organs responsible for producing sperm cells and testosterone hormone. Located in the scrotum, they consist of seminiferous tubules where sperm cells are produced and Leydig cells that produce testosterone. Essential for sexual development and fertility.

Gonads

Organs responsible for producing gametes (eggs or sperm) and secreting sex hormones. Found in males (testes) and females (ovaries).

Seminiferous tubules

Tightly Coiled

Where sperm production occurs

Sertoli Cells

Cells that surround, support, and nourish developing sperm cells.

Interstitial Cells

Cells that fill the spaces between tubules and secrete male sex hormones.

Spermatogonia

Diploid germ cells

Primary Spermatocytes

Secondary Spermotocytes

Spermatids

S

Budding

New individuals arise from outgrowths of existing ones

Fission

The separation of a parent organism into two individuals of equal size (common in vertebrates

Fragmentation

Is breaking of the body into pieces, some or all of which develop into adults

Parthenogenesis

The development of a new individual from an unfertilized egg

Prostate gland

Surrounds part of the urethra and secretes an alkaline fluid that activates sperm to swim.

Bulbourethral Glands

Secretes an alkaline mucus that prepares the urethra for sperm, attach to the urethra

Acrosome

A cap-like structure that helps the mature sperm cell to penetrate the cell.

Polar body

A haploid cell that contains almost no cytoplasm

Menstruation

When the uterus sheds its lining each month

Menstrual Flow

Exits the body through the cervix and vagina

Menstrual Cycle

Prepares the uterus for pregnancy

Estrogen & Progesterone

Primarily regulates the menstrual cycle.

Yolk sac

Makes blood cells into the liver takes over this job at six weeks

Allantois

An outpouching of the yolk sac, gives rise to blood vessels in the umbilical cord

Amnion

contains fluid that cushions the embryo and maintains constant temperature and pressure.

chorion

The outermost membrane, produces chronic villi that project into the uterine lining and exchange nutrients with maternal blood.

Chorionic Villi

eventually develop into the placenta, which is an intricate connection between fetal and maternal circulation.

Primitive Streak

An axis which other structures organize around as they develop

Notochord

Forms the framework of the vertebral column

Neural Groove

The first step in nervous system development.

Neural Tube

Neural groove folds into this, which will eventually become the brain and spinal chord.

Vas Deferens

Duct that carries sperm from the epididymis to the ejaculatory duct

Bulbourethral Glands

Secretes Alkaline mucus to coat urethra for sperm ejaculation

Interstitial Cells

Cells within the testes that secrete male sex hormones

Urethra

The tub that extends from ejaculatory duct through the penis and carries out semen from the body

Prostate Gland

Secretes an alkaline fluid that activates the sperm to swim

Follicle Cells

Cells responsible for providing nourishment to oocyte cells

Spermatozoa

Spermatids develop flagella and complete their differentiation into mature sperm cells called ______ in the lumen of the seminiferous tubule.