#Question id: 4256
#Unit 2. Cellular Organization
With respect to CpG islands in our genomic DNA, which, if any, of the following descriptions do not apply?
1) frequently occurring (there are about 30,000 in the human genome).
2) long DNA sequences (typically from 10 kb to 100 kb in length).
3) low CG dinucleotide frequency.
4) frequently associated with transcriptional start sites.
#Question id: 4718
#Unit 2. Cellular Organization
All the following statements about destruction of cyclins are true, except:
#Question id: 10530
#Unit 2. Cellular Organization
The transfer of a lipid molecule across a bilayer, a process termed:
#Question id: 10531
#Unit 2. Cellular Organization
Flippases catalyze translocation of the aminophospholipids:
#Question id: 10532
#Unit 2. Cellular Organization
A closed, self-sealing solvent-filled vesicles that are bounded by only a single bilayer, known as:
#Question id: 10533
#Unit 2. Cellular Organization
Following statements are regarding to the fluidity of a bilayer.
A. A lipid bilayer cools below a characteristic transition temperature, it undergoes a sort of phase change in which it becomes a liquid; that is, it loses its fluidity.
B. Above the transition temperature, the highly mobile lipids are in a state known as a liquid crystal.
C. The bilayer is thicker in the gel state than in the liquid crystal state due to the stiffening of the hydrocarbon tails at lower temperatures.
D. The transition temperature of a bilayer decreases with the chain length and the degree of saturation of its component fatty acid residues for the same reasons that the melting points of fatty acids increase with these quantities.
Which of the following combination is correct?