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Basic rhythm - control centers in medulla oblongata, spirograph and normal tidal cycle

By: HWC, Views: 7574

• Normal ventilation is rhythmic and involves continuous cycles of inspiration and expiration. • Various regions of the brain closely regulate this rhythmic pattern of ventilation. • The rhythmicity area in the medulla regulates the basic rhythm of ventilation. • The medullary rhy...

Calvin Cycle Explained!

By: HWC, Views: 7429

he light-independent reactions make sugars by way of a cyclic pathway called the Calvin cycle. The cycle begins when rubisco attaches a carbon from carbon dioxide to ribulose bisphosphate. The molecule that forms splits into two molecules of PGA. Each PGA gets a phosphate group from ATP a...

Red alga life cycle Animation

By: HWC, Views: 1917

Life cycle of Porphyra. The most conspicuous part of this algal life cycle is the haploid gametophyte. This sheetlike form is collected and dried for use as nori, the wrapping for sushi. Gametes form in packets interspersed between vegetative cells near the sheet margins. The gamet...

Hormones and the menstrual cycle Animation

By: HWC, Views: 4646

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...

Cardiac Cycle (Part 4 of 4)

By: Administrator, Views: 10868

Diastole and systole are two phases of the cardiac cycle. They occur as the heart beats, pumping blood through a system of blood vessels that carry blood to every part of the body. Systole occurs when the heart contracts to pump blood out, and diastole occurs when the heart relaxes after contract...

HIV replication/ Replication cycle of HIV

By: HWC, Views: 4905

Replication cycle of HIV, one of the retroviruses. The HIV virus is surrounded by a lipid envelope with embedded proteins. A coat of viral proteins surrounds two strands of RNA and the enzymes used during replication. The virus attaches to and enters the host cell. Viral reverse trans...

Carbon fixing adaptations Animation

By: HWC, Views: 1796

Different plants trap carbon by different pathways. Most C3 plants evolved in moist, temperate zones. On hot dry days they close their stomata to conserve water and oxygen accumulates. Under these circumstances, the enzyme rubisco uses oxygen in an inefficient reaction that competes with t...

Female Reproductive System - Hormonal regulation (GnRH) الجهاز التناسلي للأنثى - التنظيم الهرموني

By: HWC, Views: 8142

• There is a complex interaction between the anterior pituitary gland, the hypothalamus, the ovaries and the uterus that leads to the monthly changes that women experience during their monthly reproductive cycle. • Two monthly cycles constitute these changes: • Ovarian cycle. • Uter...

Calvin cycle (The light-independent reactions )

By: HWC, Views: 7477

The light-independent reactions of photosynthesis occur in the stroma of the chloroplast. Carbon dioxide enters the leaf through tiny pores or stomata and diffuses into the chloroplast. The first stage of the Calvin cycle is the attachment of a carbon dioxide molecule to a 5-carbon ribulose bi...