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Results for: 'Protozoan conjugation is an unusual form of sexual reproduction Animation'
Primate Evolutionary Tree Animation
By: HWC, Views: 3903
Presumed evolutionary branchings in the primate family tree. The first primates arose between 85 and 65 million years ago. The common ancestor of apes and hominids branched off from Old World monkeys about 23 million years ago. The hominid lineage, which includes humans and earlier humanlik...
Molecules, Membrane Permeability and Structure
By: HWC, Views: 7211
Organisms are not isolated system at equilibrium and need to intake nutrients and electrolytes as remove wastes. Similarly Cells within an organism must also exchange compound by passing them through membrane. The permeability of a membrane is the rate of passive diffusion of molecules th...
Mendel's pea plant, Pisum sativum experimental
By: HWC, Views: 5614
Mendel chose the garden pea plant, Pisum sativum, for experimental tests of his ideas about inheritance. Under normal circumstances, the garden pea plant is self-fertilizing. This cross-section shows the gamete-forming structures. Sperm-producing pollen grains form in the stamens. Eggs deve...
By: HWC, Views: 5698
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...
Origin of organelles Animation
By: HWC, Views: 1399
Possible origins of the nucleus and other organelles. Some prokaryotic cells have infoldings of their plasma membrane. These infoldings may have served as channels from the cytoplasm to the cell surface. These membranous folds may have evolved into the endoplasmic reticulum and the nuclear e...
Coronary Heart Disease Animation
By: Administrator, Views: 11024
Arteriosclerotic heart disease occurs when arterial vessels are marked by thickening, hardening, and loss of elasticity in arterial walls. Course of cardiovascular disease accelerates due to: Reduced blood flow Rlevated blood lipids Defective endothelial repair
Peptide Bond Formation Animation
By: HWC, Views: 1559
During protein synthesis, peptide bonds link amino acids together in the order specified by DNA instructions. In this case, the first two amino acids in the protein are methionine and alanine. Here are ball-and-stick models of these amino acids. Peptide bond formation is a type of condensatio...
By: HWC, Views: 7505
• Non-specific and specific defense mechanisms work through the functions of complement proteins. • As soon as pathogens penetrate the physical barrier of the skin, other resistance mechanisms begin. • Cells, such as macrophages, phagocytize pathogens. • These cells increase exposu...
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