2. In the process of proving that DNA is genetic material, the experiment of T2 phage infecting E.coli played an important role. The following statement about phage is correct.
A.T2 phage can also replicate and proliferate in pneumococcus.
B.mRNA and protein can be synthesized in T2 phage virus particles.
C 32P in the culture medium can appear in the nucleic acid of T2 phage after being ingested by the host.
D. The nucleic acid types and proliferation process of D.HIV and T2 phage are the same.
The answer to this question is C.
3. The following statements about enzymes in organisms are correct.
A. in cells, no enzymes are involved in DNA synthesis outside the nucleus.
Enzymes produced by living cells have catalytic activity in vitro.
Pepsin can be precipitated from the extract by salting out.
D. The optimum temperature and preservation temperature of salivary amylase catalytic reaction is 37℃.
The answer to this question is C.
4. Put the mature white liquor of a certain plant into a solution of substance A with a certain concentration, and find out the volume change trend of its protoplast (that is, the part in the cell wall of the plant cell), as shown in the figure. The following statement is correct.
Substance a did not enter the cell through the cell membrane within 0 ~ 4h hours.
B the cell volume and protoplast volume change equally within 0 ~ 65438±0h.
The osmotic pressure of substance A solution is less than that of cell fluid in 2 ~ 3h.
In the range of 0 ~ 1h, the osmotic pressure of liquid in vacuole is greater than that of cytoplasmic matrix.
The answer to this question is C.
The above are some of the questions and answers in the two-volume science comprehensive examination paper of the national college entrance examination for reference only.