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Egg and Sperm Formations in Animals Animation

By: HWC, Views: 2119

Inside the ovaries of a female animal are diploid germ cells called oogonia. An oogonium grows to become a primary oocyte. This large cell is still diploid. Meiosis I followed by unequal cytoplasmic division produces one large secondary oocyte and a smaller polar body. Both are haploid. ...

Phases of the Female Reproductive Cycle - Hormonal regulation

By: HWC, Views: 8330

FSH, LH and estrogen • FSH travels through the bloodstream from the anterior pituitary to the ovaries. • FSH promotes follicular growth. Increased follicular growth promotes estrogen production. • Small increases in blood estrogen levels inhibit the release of FSH and LH into the bl...

Primary and secondary response to infection

By: HWC, Views: 7636

• Pathogens enter the body by penetrating the non-specific barriers in the skin and mucus membranes. • Pathogens first encounter macrophages and natural killer cells that carry out phagocytosis and cytolysis respectively. • A pathogen's first encounter with the immune system can promo...

Ear Animation

By: Administrator, Views: 12158

The ear is generally described as having three distinct divisions, each with distinct functions: External ear Middle ear Inner ear The ear contains structures for both the sense of hearing and the sense of balance. Eighth cranial nerve: Also called the acoustic or auditory nerve. Carries...

ribosome

By: HWC, Views: 7613

The trp operon in E. coli contains five structural genes corresponding to enzymes that convert chorismate into tryptophan. The trpE gene contains a 5' untranslated region that plays an important role in the regulatory mechanism called attenuation. The 5' UTR contains four regions. Region 1 en...

Proteins

By: HWC, Views: 6939

Living things must accomplish a great number of tasks just to get through a day, and these tasks are accomplished by a diverse range of biological molecules. In the range of tasks that molecules accomplish, however, proteins reign supreme. Almost every chemical reaction that takes place in living...

What are Taste Receptors? How Does it Work? Animation

By: HWC, Views: 4751

Do you ever wonder how you can taste the foods you eat? It all starts with taste receptors in your muscular tongue. Taste receptor neurons are found in your taste buds but you are not looking at the taste buds. The raised bumps on the surface of the tongue that you see are specialized epith...

Secondary Active Transport

By: HWC, Views: 8426

Energy stored (in a hydrogen or sodium concentration gradient) is used to drive other substances against their own concentration gradients Secondary active transport, is transport of molecules across the cell membrane utilizing energy in other forms than ATP. In many cells, antiporters mov...

Hormones and the menstrual cycle Animation

By: HWC, Views: 4818

Feedback loops to the hypothalamus and pituitary gland from the ovaries during the menstrual cycle Animation for a step-by-step explanation. Production of a releasing hormone (GnRH) by the hypothalamus prods the pituitary's anterior lobe to release FSH and LH. In the ovary, FSH and LH stimula...