Question

Because many genes are organized in hierarchies, the expression of a small number of genes can trigger the expression of hundreds of other genes. This gene expression is known as a:

1) Cascade
2) Promiscuity
3) Gene recruitment
4) The possession of a "genetic toolkit"

Answer 1

The correct answer is a cascade, which describes the sequential expression and interaction of genes leading to complex phenotypic outcomes as part of gene regulation. Cascade events are crucial for development and can lead to disorders if they malfunction.

Step-by-step explanation:

The expression of a small number of genes that triggers the expression of hundreds of other genes is known as a cascade.

This concept relates to gene regulation where certain key genes, when activated, can initiate a series of events or reactions that contribute to numerous outcomes, such as the development of an organ, through sequential expression or the combined effect of multiple genes, which is part of polygenic inheritance.

In biology, understanding how genes interact, whether they are complementary, synergistic, or opposing, and how gene expression is regulated is crucial, especially since malfunctions in gene regulation can lead to diseases like cancer.