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Effect of the environment on coat color in the Himalayan rabbit Animation

By: HWC, Views: 3262

An organism's phenotype—the combination of traits that we observe—is the product of interactions between its genotype and the environment. For example. a Himalayan rabbit is completely white at birth. But within weeks, the fur on the rabbits ears, nose, tail. and lower legs darkens. The...

New DNA Strand Replication

By: HWC, Views: 7141

First step: strands are separated • Helicase unwinds the DNA double helix at the replication fork • SSBs coat the single strands to prevent reannealing • Polymerase attaches nucleotide at 3' end • Synthesis is in 5' to 3' direction DNA Polymerase: • Only extends nucleic ac...

Subunits of DNA And Semi Conservative Replication

By: HWC, Views: 4068

Adenine is a purine with a double-ring structure. In double-stranded DNA, adenine base-pairs with thymine. Guanine is a purine with a double-ring structure. In double-stranded DNA, guanine base-pairs with cytosine. Thymine is a pyrimidine with a single-ring structure. In double-stranded DNA, th...

Peptide Bond Formation Animation

By: HWC, Views: 1556

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...

Mitochondrial Structure & ETC Protein Complexes (Protein Complexes and Electron Transport)

By: HWC, Views: 7362

The energy carrying molecules, NADH and FADH2, that were generated in glycolysis and the Krebs cycle, now are processed in the mitochondria where their high energy electrons are deposited in an electron chain complex located in the inner mitochondrial membranes. These high-energy electrons now dr...

Antidiuretic hormone (vasoconstriction, water reabsorption & sweat inhibition)

By: HWC, Views: 7617

• Dehydration, blood loss, and low amounts of water in the blood can cause blood volume and pressure to decrease. • Neurosecretoxy cells in the posterior pituitary release antidiuretic hormone(ADH). • ADH binds to smooth muscle cells in blood vessel walls, stimulating them to vasoconstr...

Male Reproductive System - Testosterone

By: HWC, Views: 8341

• Under the influence of FSH and testosterone, Sertoli cells produce androgen-binding protein (ABP) that binds to testosterone and maintains high levels of the hormone near spermatogenic cells. • Testosterone stimulates the final stages of spermatogenesis. • In addition, testosterone is...