Sarcomere

Within each skeletal muscle cell are many myofibrils consisting of a repeating array of a specialized structure

TLS Online TPP Program

#Id: 8969

#Section 3: Genetics, Cellular and Molecular Biology

The amount of genetic variation by examining phenotypic variation was difficult because many traits, a complex interaction of many genes and environmental factors determines the phenotype

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#Id: 2240

#Section 3: Genetics, Cellular and Molecular Biology

The neutral-mutation hypothesis proposes that most molecular variation is neutral with regard to natural selection and is shaped largely by mutation and genetic drift.

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#Id: 8971

#Section 3: Genetics, Cellular and Molecular Biology

The Death of a Gene

When a gene is duplicated, the new copy is often dead-on arrival (lacks the regulatory elements). 

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#Id: 2244

#Section 3: Genetics, Cellular and Molecular Biology

When a nonfunctioning duplicate is fixed in the population, or a functioning gene becomes nonfunctional, the result is a genetic skeleton called a pseudogene.

Deletions are important in shaping the genome.

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#Id: 2245

#Section 3: Genetics, Cellular and Molecular Biology

Deletion plays a key role in gene trafficking.which is the movement of genes to new sites in the genome.

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#Id: 2246

#Section 3: Genetics, Cellular and Molecular Biology

Some people have an allele called Δ32 at the CCR5 locus in which 32 bp are deleted.

CCR5 that plays a role in inflammatory response. Unfortunately, this protein is also a key to human immunodeficiency virus (HIV) infection. The virus binds to a loop of the CCR5 protein and then enters the cell.

The missing part of the gene codes for the loop in the protein to which the virus attaches.