Positive assortative mating refers to a tendency for like individuals to mate. For example, humans exhibit positive assortative mating for height.

TLS Online TPP Program

#Id: 10397

#Unit 4. Cell Communication and Cell Signaling

Mutations in three broad classes of genes have been implicated in the onset of cancer. 

Protooncogenes

Tumor-suppressor genes

genome maintenance genes

TLS Online TPP Program

#Id: 10398

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 10399

#Unit 4. Cell Communication and Cell Signaling

Loss-of-function mutations:

1. A deletion of all or part of a gene.

2. A point mutation in the coding sequence that introduce a stop codon or a frameshift.

TLS Online TPP Program

#Id: 10400

#Unit 4. Cell Communication and Cell Signaling

Gain-of-function mutations:

1. Duplication or amplification of the gene

2. A point mutation that results in a hyperactive or constitutively active protein product

TLS Online TPP Program

#Id: 10401

#Unit 4. Cell Communication and Cell Signaling

Gain-of-function mutations:

1. A promoter mutation resulting increased expression 

2. A DNA rearrangement that places the gene under the control of an enhancer or promoter that results in increased or inappropriate expression of the protein product

TLS Online TPP Program

#Id: 10402

#Unit 4. Cell Communication and Cell Signaling