Which one of the following molecules is able to move across the cell membrane by simple diffusion?
A. DNA
B. hemoglobin
C. carbon dioxide
D. starch
E. glucose
Answer: C. carbon dioxide
You might also like to view...
Glycolysis depends on a continuous supply of:
a. oxygen b. pyruvate c. NAD+ d. NADH e. H2O
A motor neuron and all the muscles under its control are called what kind of unit?
a. end b. movement c. muscle d. motor e. coordination
A lifestyle that meets the needs of the present generation without reducing the ability of future generations to meet their own needs is referred to as _______ living.
Fill in the blank(s) with the appropriate word(s).
Investigators performed nuclear transplant experiments to determine whether DNA is altered irreversibly during development. Which of the following statements about these experiments is true?
(a) Because the donor nucleus is taken from an adult animal, the chromosomes from the nucleus must undergo recombination with the DNA in the egg for successful development to occur. (b) The embryo that develops from the nuclear transplant experiment is genetically identical to the donor of the nucleus. (c) The meiotic spindle of the egg must interact with the chromosomes of the injected nuclei for successful nuclear transplantation to occur. (d) Although nuclear transplantation has been successful in producing embryos in some mammals with the use of foster mothers, evidence of DNA alterations during differentiation has not been obtained for plants.