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Body plan of euglena Animation

By: HWC, Views: 2068

Euglenoids are single-celled organisms that live in lakes and ponds. A contractile vacuole pumps out the water that diffuses into the cell from its hypotonic surroundings. The body is covered by a translucent pellicle composed of flexible strips of a protein-rich material. Light passe...

The Lac Operon in E. Coli

By: Administrator, Views: 11808

The lac operon (lactose operon) is an operon required for the transport and metabolism of lactose in Escherichia coli and many other enteric bacteria. Although glucose is the preferred carbon source for most bacteria, the lac operon allows for the effective digestion of lactose when glucose is no...

Buffers definition and the role of buffer in the body

By: HWC, Views: 7897

■ Too many H+ break hydrogen bonds and a protein comes apart. ■ Buffers react with excess H+ to protect proteins from breaking down. ■ Buffers consist of weak acid plus anions of that weak acid. This solution contains: • hydrogen ions • weak acid (H2CO3) • anions of we...

Olfaction. or the sense of smell

By: HWC, Views: 5175

Do you ever wonder how you can distinguish thousands of different odors? Olfaction. or the sense of smell, is used by all mammals to navigate, find food, and even find mates. We have millions of olfactory receptors for smelling in our nose. These receptor neurons bind water-soluble or volatil...

How antibiotics works? 💊

By: HWC, Views: 7450

The Crisis in Antibiotic Resistance More than 70 years ago, Alexander Fleming discovered penicillin. A few decades later, when this antibiotic was used in World War II, Fleming's discovery had revolutionized medicine. No longer did people have to die from something as trivial as an infected cut.Y...

DNA Replication Factory and Protein

By: HWC, Views: 7256

DNA (deoxyribose nucleic acid) carries all the genetic information needed to re-create itself and to pass on the characteristics of the organism. The “factory” model of DNA replication hypothesizes a specific nuclear structure in which the molecular machinery for replication forks are brou...

Hormonal regulation of blood pressure - RAA system

By: HWC, Views: 8172

■ Long-term regulation of MABP is under hormonal control. • Hormones that affect blood pressure and volume: the renin-angiotensin-aldosterone (RAA) system, antidiuretic hormone (ADM), and atrial natriuretic peptide (ANP). ■ Most important hormonal regulator of MABP. Activated by drop in...

Male Reproductive System - The gonadotropin releasing hormone

By: HWC, Views: 8484

• Hormonal mechanisms that influence male reproductive function involve endocrine tissues contained in the: • Hypothalamus of the brain. • Anterior pituitary. • Testes. • In the hypothalamus, certain neurosecretory cells secrete gonadotropin- releasing hormone (GnRH). • GnRH ...

Phases of mitosis

By: HWC, Views: 5690

Prophase is the first step in the mitotic process. During prophase, the chromosomes condense. The centrosomes begin to form a spindle and move into position on opposite sides of the cell. Sister chromatids are held together by a protein called cohesin at the centromere. Prometaphase is the sec...