Which of the following is absolutely necessary for diffusion to occur?
a. a phospholipid bilayer
b. a living cell
c. a selectively permeable membrane
d. a concentration gradient
Ans: d. a concentration gradient
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Which statement describes evidence in support of the endosymbiont theory?
A) The sequence of mitochondrial rRNA genes are most similar to the rRNA genes in purple bacteria. B) Mitochondrial and chloroplast DNA is organized into nucleosomes. C) Mitochondria and chloroplasts have genes that allow them to live independently. D) Mitochondria, chloroplasts, and cytoplasmic translation are inhibited by antibiotics such as chloramphenicol.
A population of a species that is distinguishable from other populations by one or more characteristics is referred to as a(n) ________
Fill in the blank(s) with correct word
________ is the hormone that stimulates the production of testosterone by the interstitial cells of the testis
Fill in the blank(s) with correct word
What gives blue cheeses such as Roquefort and Stilton their unique flavor?
A) Ascomycete mold B) Alcohol C) Yeast D) Chytrids E) Mushrooms