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Sex-Linked Traits! How are eye colors inherited in fruit flies?

By: HWC, Views: 5745

The eye color gene is located on the X chromosome (one of the sex determining chromosomes of Drosophila). White eye color is recessive. When a red eyed male mates with white eyed females, their daughters will have red eyes, but their sons will have white eyes.

Natural Selection, Species Isolation and Real World Example

By: HWC, Views: 6080

`Natural selection' is the process in which organisms with adaptive traits survive and breed in greater number than organisms without such traits. Eventually, almost all of the individuals in the population will have the same adaptive trait. This was the concept presented by Charles Darwin in ...

Fertilization Animation

By: Administrator, Views: 371

At conception, the gender and other biologic traits of the new individual are determined. The zygote is genetically complete and immediately begins to divide, forming a solid mass of cells called a morula. When the developing embryo (stage of development between weeks 2 and 8) reaches the ute...

Introduction to Genetics

By: Administrator, Views: 9499

Genetics is a branch of biology concerned with the study of genes, genetic variation, and heredity in organisms. Gregor Mendel, a scientist and Augustinian friar, discovered genetics in the late 19th-century. Mendel studied "trait inheritance", patterns in the way traits are handed down from p...

Stress and Immune System Animation

By: Administrator, Views: 9872

How stress and the immune system are linked. Immune response declines with age, limiting body's ability to identify and fight foreign substances. Loss of thymus cortex leads to reduced production of T lymphocytes, including T cells, NK cells, B lymphocytes. Frequency and severity of infectio...

Darwin's Observation (Fossils, Galapagos Islands & Africa ) and Natural Selection (Adaptive Traits)

By: HWC, Views: 6555

Along Darwin's voyage, he made many observations. Each one added to his understanding of how organisms change over time. Darwin was already familiar with fossils and knew that many fossils were very different from living organisms. But, also there were some fossils that were very similar to li...

Introduction to Macular Degeneration

By: Administrator, Views: 9471

Macular degeneration An incurable, age-related, progressive eye disease that affects more than 10 million Americans. Leading cause of blindness for those ages 55 and older. Macular degeneration For the first time, researchers have linked gene defects to macular degeneration. Could lead to ...

Mendel's Pea Experiment

By: HWC, Views: 6059

Sugar snap peas were common garden plants during Mendel's lifetime and many varieties undoubtedly grew in the abbey gardens. An avid gardener. this is where Mendel first made observations about pea plants. He noticed that certain characteristics of peas were passed from generation to generation. ...

Anatomy and Chemical Makeup of a Single Hair (Animation)

By: HWC, Views: 4916

The hair's outer cuticle surrounds hair cells filled with tough keratin macrofibrils. Each macrofibril consists of smaller microfibrils. A microfibril is made up of three keratin polypeptide chains. The chains are linked together by disulfide bonds. A hair consists of keratin chains held...