Every living organism must have ____
a. at least one cell
b. a nucleus
c. a cell wall
d. mitochondria
e. oxygen
ANSWER: a
You might also like to view...
Scientists have found that the lifetimes of mRNAs coding for pair-rule regulatory elements in Drosophila embryos may last only a few minutes. What does this suggest about the overall developmental plan of an animal body?
A) The role of mRNAs is less important than the position of genes in chromosomes. B) Homeotic genes have greater impact in forming an embryo than mRNA from pair-rule genes. C) Building an animal body requires a sequence of precisely timed steps. D) Timing of pair-rule sequence determination is not as important as spatial signaling.
The capacity of an organism to produce a toxin is called ________.
Fill in the blank(s) with the appropriate word(s).
In a cow's udder, milk
A. contains Lactococcus. B. contains Lactobacillus. C. is acidic. D. is sterile.
The endomembrane system did not start developing until the atmosphere was ____
a. high in oxygen, high in carbon dioxide b. high in hydrogen, low in oxygen c. changing from low oxygen to high oxygen levels d. firmly in the age of aerobes e. low in hydrogen, low in oxygen