Provide a brief description of the variable gene activity hypothesis as it relates to development. What information is often provided in support of this hypothesis?
What will be an ideal response?
Because all cells apparently have the same genetic information, yet may differ structurally and functionally, the variable gene activity hypothesis suggests that differential gene transcription (genetic regulation) accounts for such cellular diversity. Evidence in support of this model includes the following: chromosome puffs, isozymes, and the presence of genes but no gene products in some tissues (hemoglobin, for example).
You might also like to view...
Which of the following statements best describes the habitats of Achromobacter, Alcaligenes, and Bordetella?
a. The habitats are limited to the upper res-piratory tract of various mammals. b. The habitats vary from the soil and water environment to the upper respiratory tract of various mammals. c. The habitats are limited to the soil and water environment. d. The habitats are limited to the mucous membranes of humans and animals.
What part of the reef receives the full impact of wave energy?
a. Forereef b. Drop off c. Reef crest d. Back reef
When a population is made up of individuals
who are genetically identical, each individual is said to be a ____ of other individuals.
a. homolog b. clone c. twin d. recombinant e. probe
Histamine, serotonin, and bradykinin are all
A. mediators that increase chemotaxis. B. mediators of T-cell activity. C. fever inducers. D. mediators of B-cell activity. E. vasoactive mediators.