GENETICS
What nitrogenous base is present in DNAs but not in RNAs?
Thymine
What is osmosis?
The movement of water through a membrane from a low to a high solute concentration.
What are the four major classes of biomolecules?
Carbohydrates, lipids, proteins, nucleic acids
What is CRISPR technology?
Gene-editing technology for precise DNA modification.
In DNA replication, new strands are synthesized from _ to _ direction.
5' , 3'
State the 2 differences between 70S and 80S ribosomes
Larger/denser, 80S ribosomes only exist in eukaryotic cells, 70S exist in some organelles and prokaryotic cells
What is the net ATP yield of glycolysis?
2
State one biotechnology/process involved in DNA profiling.
PCR, Gel Electrophoresis
Arctic foxes typically have a white coat in the winter. In summer, when there is no snow on the ground, the foxes typically have a darker coat. Which of the following is most likely responsible for the seasonal change in coat color?
A. The decrease in the amount of daylight in winter causes a change in gene expression, which results in the foxes growing a lighter-appearing coat.
B. The diet of the foxes in summer lacks a particular nutrient, which causes the foxes to lose their white coat
C. Competition for mates in the spring causes each fox to increase its camouflage with the environment by producing a darker-appearing coat
D. The lower temperatures in winter denature the pigment molecules in the arctic fox coat, causing the coat to become lighter in color
A
Chloroplasts has developed extensive thylakoid membranes for which purpose?
To efficiently absorb light energy
State 3 coenzymes that are part of either photosynthesis or cellular respiration (or both).
NADPH/NADP, NADH/NAD, FADH/FAD, Coenzyme A,
Agarose gel electrophoresis is a laboratory method utilized to separate DNA fragments based on:
A. Size
B. Concentration
C. Charge
D. Nucleotide composition
A
A scientist adds a chemical to a culture of dividing cells in order to disrupt DNA replication. Replicated DNA by the cells is double-stranded, but sections of it lack covalent bonds between adjacent nucleotides. Which of the follow claims is best supported?
A. The chemical prevents the formation of RNA primers
B. The chemical inhibits DNA ligase
C. The chemical blocks DNA polymerase
D. The chemical disrupts hydrogen bonding
B
This cell has multiple nuclei, membrane capable of impulse propagation, visible bands, and is in long and cylindrical shapes. What is this cell?
A. Cardiac muscle fibers
B. Smooth muscle fibers
C. Skeletal muscle fibers
D. Type I pneumocyte
C
How does gurgling with saltwater help with sore throats? (hint: a specific transport involving cell membranes)
Saltwater is a hypertonic concentration compared to the cells located at the throat, and thus helps water to leave the throat through osmosis, lessening the swelling.
Why does the PCR procedure require the usage of heat-resistant DNA polymerase?
The denaturation process involves high temperatures and could thus denature normal DNA-polymerase and thus prevent the process of synthesizing a new DNA strand.
The human TPM1 gene encodes members of the tropomyosin family of cytoskeletal proteins. Which of the following best explains how different proteins can be made in different cell types from the one TPM1 gene?
A. Different introns are selectively converted to exons
B. Different exons are retained or spliced out of the primary transcript
C. The GTP cap is selectively added to and activates different exons
D. Different portions of the primary transcript remain bound to the template of DNA
B
A researcher treated cells with a novel antibiotic that specifically inhibits the elongation factor Tu (EF-Tu) in bacterial ribosomes. Unexpectedly, they observed a significant reduction in mitochondrial protein synthesis but no effect on cytosolic protein synthesis. What theory does this phenomenon support?
The endosymbiotic theory
State one radioisotope used for imaging thyroid cancer.
Iodine-131, Iodine-123, Iodine-124
A researcher is attempting to clone a gene into a plasmid vector using two different restriction enzymes, EcoRI and BamHI. However, they notice that the gene fragment they've isolated has multiple EcoRI sites but only one BamHI site. Which of the following cloning strategies could be used to efficiently overcome this issue and successfully clone the gene into the vector?
A. Partial digestion of the gene fragment at the EcoRI sites
B. Site-directed mutagenesis to eliminate the EcoRI sites in the gene
C. Ligation of synthetic DNA linkers containing specific restriction sites
D. Using a different restriction enzyme that has a single cut site in the gene fragment
D