Which of the following statements is correct about passive diffusion?
A) It requires an expenditure of energy by the cell.
B) It is a process in which molecules move from a region of higher concentration to a region of lower concentration (or down a concentration gradient).
C) It is a process in which molecules move from a region of lower concentration to one of higher concentration (or up a concentration gradient).
D) It may require a transport protein.
E) It involves movement of molecules down a concentration gradient and may require a transport protein.
E
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Upon ingestion of a food particle by a protozoan, the food particle is in a/an
A. lysosome. B. mitochondrion. C. endoplasmic reticulum. D. phagocytic vacuole.
Choose the organelle in column 2 that best matches the activity in column 1.
A) There is no appropriate match. B) Mitochondria C) peroxisomes D) mitochondria E) there is no appropriate match F) lysosome G) smooth endoplasmic reticulum 1) test for catalase activity 2) test for the TCA cycle enzymes 3) test for the presence of cytochromes 4) look for fractions that are green 5) hydroxylation of compounds including phenobarbital 6) presence of acid hydrolases 7) ribulose bisphosphatase activity is present
Rotifers possess
a. cilia. b. a mouth. c. protonephridia. d. nerve cells. e. all of these.
Assume that a cross is made between two organisms that are both heterozygous for a gene that shows incomplete dominance. What phenotypic and genotypic ratios are expected in the offspring?
A) phenotypic 1:2:1; genotypic 1:3 B) phenotypic 1:2:1; genotypic 1:1:1:1 C) phenotypic 1:2:1; genotypic 1:2:1 D) phenotypic 1:1:1:1; genotypic 1:2:1 E) phenotypic 3:1; genotypic 1:2:1