Fossil evidence indicates that horses have gradually increased in size over geologic time. Which of the following terms best describes this?
A) artificial selection
B) directional selection
C) stabilizing selection
D) disruptive selection
E) sexual selection
Ans: B) directional selection
You might also like to view...
A strategy used by dissimilatory metal-reducing bacteria that enable their use of insoluble compounds as electron acceptors is to transfer electrons to the metal via external, intermediary compounds such as ________ found in the environment or ________. These compounds are collectively known as ________.
What will be an ideal response?
In the first stage of the ovarian cycle, what gamete cell starts to develop?
a. polar body b. primary oocyte c. secondary oocyte d. follicle cells e. corpus luteum cells
Which of the following is true about histone acetyltransferase (HAT)?
A) HATs will make the chromatin more compacted and less available to transcription regulatory proteins. B) HATs will remove acetyl groups from histone proteins. C) HATs have an overall effect of increasing the positive charges on DNA. D) HATs will add acetyl groups to DNA. E) HATs are usually linked to increasing gene expression.
What do cytotoxic T cells interact with?
A. MHC class I proteins and viral or cancer cell peptides B. MHC class I and MHC class II proteins C. Viral or cancer cell peptides only D. MHC class I proteins only E. MHC class II proteins and viral or cancer cell peptides F. MHC class II proteins only