week 3 wrap up quiz
B
A bacterial cell, a plant cell, and an animal cell would have which of the following structures in common? A. nucleoid B. cytoplasm C. nucleus D. cell wall E. vacuole
C
A double stranded DNA molecule is determined to have 15% cytosine (C). How much adenine (A), thymine, (T) and guanine (G) are in this DNA molecule? A. 15% A, 35% T, and 35% G B. 15% A, 15% T, and 15% G C. 35% A, 35% T, and 15% G D. 35% A, 15% T, and 35% G
C
Cells can change the composition of their plasma membranes as a response to changing environments. In general, colder temperatures reduce the fluidity of the membrane, so cells will produce different molecules to bring the fluidity back to normal. How could the cell change the membrane in response to colder temperatures? A. decrease the amount of unsaturated fatty acids B. increase the length of the fatty acid side chains in the phospholipids C. increase the amount of unsaturated fatty acids D. increase the amount of saturated triacylglycerols
B
Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes? A. The purines would be separated from the deoxyribose sugars. B. The phosphodiester linkages of the polynucleotide backbone would be broken. C. The two strands of the double helix would separate. D. The pyrimidines would be separated from the deoxyribose sugars.
B
If cells are grown in a medium containing radioactive 32P-labeled phosphate, which of these molecules will be labeled? A. glucose B. nucleic acids C. proteins D. amino acids
false
True or false: A single molecule is always either hydrophobic or hydrophilic, and can never possess (at the same time) a region that is hydrophobic and a region that is hydrophilic.
C
Which of the following DNA sequences is complementary to the DNA sequence 5' - GATCGACTTC - 3' A. 3' - GAAGUCGAUC - 5' B. 5' - CTAGCTGAAG - 3' C. 5' - GAAGTCGATC - 3' D. 3' - CUAGCUGAAG - 5'
B
Which of the following is TRUE about this molecule? A. This molecule is found in DNA. B. This molecule is found in RNA. C. This molecule could be found in either RNA or DNA. D. This molecule is an amino acid.
D
Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA? A. 5'-purine-pyrimidine-purine-pyrimidine-3' with 3'-purine-pyrimidine-purine-pyrimidine-5' B. 5'-AGCT-3' with 5'-TCGA-3' C. 5'-GCGC-3' with 5'-TATA-3' D. 5'-ATGC-3' with 5'-GCAT-3' E. All of these pairs are correct.
D
Which one of the following would be LEAST likely to cross a lipid bilayer on its own? A. H2O B. CO2 C. O2 D. Na+
C
You are looking at some cells under the microscope. Which of these choices correctly describe a characteristic that could help you determine a cell is an animal cell or a plant cell? A. The cell has ribosomes, it must be a plant cell. B. The cell has a nucleus, it must be an animal cell. C. The cell has chloroplasts, it must be a plant cell. D. The cell has mitochondria, it must be an animal cell.
A
You have a phospholipid bilayer with equal amounts of saturated and unsaturated phospholipids. After testing the permeability of this membrane to glucose, you increase the proportion of unsaturated phospholipids in the bilayer. What will happen to the membrane's permeability to glucose? A. Permeability to glucose will increase. B. Permeability to glucose will decrease. C. You cannot predict the outcome; you simply have to make the measurement. D. Permeability to glucose will stay the same.