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

By: HWC, Views: 4917

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...

Transcription—A molecular view

By: HWC, Views: 5012

Transcription, as related to genomics, is the process of making an RNA copy of a gene's DNA sequence. This copy, called messenger RNA (mRNA), carries the gene's protein information encoded in DNA. During transcription, a DNA molecule is copied into RNA molecules that are then used to translate...

How to make cDNA Animation

By: HWC, Views: 3833

This animation shows how an mRNA transcript can be used to make a cDNA strand.

Vascular tissues in a corn stem and a buttercup root

By: HWC, Views: 3850

Vascular tissues in a corn stem and a buttercup root. The cells that make up each tissue. Xylem conducts water and dissolved ions. It also helps mechanically support a plant. The cells, called vessel members and tracheids, are dead at maturity. Their lignified walls interconnect and serve as p...

How eudicots (true dicots) differ from monocots Animation

By: HWC, Views: 4204

Most flowering plants are either monocots or eudicots. They have the same tissues, but slightly different features. Monocot seeds have a single cotyledon, or seed leaf. Eudicot seeds have two cotyledons. Monocot flowers usually have petals and other floral parts in multiples of three. Flow...

Apicomplexan life cycle Animation

By: HWC, Views: 3714

Malaria is caused by the sporozoan, Plasmodium. It is transferred to humans by mosquitoes. When an infected mosquito feeds, infective sporozoites move from her salivary glands into the human body. The bloodstream carries the sporozoites to the liver. Here, they reproduce asexually and...

Green alga life cycle Animation

By: HWC, Views: 3853

Chlamydomonas zoospores are haploid flagellated cells. As long as conditions are favorable, these cells reproduce asexually. As many as sixteen cells may form by mitosis within a parent cell. Daughter cells escape when the cell wall ruptures. When conditions become less favorable, the...

Cellular slime mold life cycle Animation

By: HWC, Views: 3618

Life cycle of Dictyostelium discoideum, a cellular slime mold Animation. Amoeba-like slime mold cells live in the soil, where they feed on bacteria. The free-living cells grow and reproduce by mitosis. When food dwindles, the amoebas stream toward one another in response to a chemical...

Ciliate conjugation Animation

By: HWC, Views: 3716

Protozoan conjugation is an unusual form of sexual reproduction Prospective partners join together, usually at the surface of their oral depressions. The cells undergo cytoplasmic fusion. Meiosis II produces four haploid micronuclei. Now the macronucleus of each cell begins to bre...