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【单选题】
We usually call codons contains 5 characteristics, among which the degeneracy of the genetic code means?（ ）
A.
Most amino acids have more than one set of codons
B.
There are many rare bases in the code which translate rare amino acids
C.
A triplet codon can lack or insert a purine or pyrimidine base
D.
At least nine codons apply to more than one amino acid
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【单选题】Although mammalian genome is huge, cells can replicate the genome in just a few minutes.Which is the most possible reason?（ ）
A.
RNA polymerases carry out replication
B.
Eukaryotic DNA polymerases are extraordinarily faster than prokaryotes
C.
Hundreds of replication forks work simultaneously
D.
The unique cell cycle
【多选题】The effective glomerular filtration pressure depends on（ ）
A.
Plasma colloid osmotic pressure
B.
Glomerular capillary blood pressure
C.
Whole body arterial blood pressure
D.
Renal intracapsular pressure
E.
Plasma crystal osmotic pressure
【多选题】The binding characteristics of Hb and O2 are（ ）
A.
Fast reaction, reversible, no enzyme catalysis
B.
Affected by PO2
C.
The binding or dissociation curve of Hb and O2 is s-shaped, which is related to allosteric effect of Hb
D.
The combination of Fe2+ and O2 is oxygenation rather than oxidation
E.
One molecule of Hb can bind four molecules of O2
【单选题】Which RNA polymerase transcribes the gene of insulin? （ ）
A.
RNA polymerase I
B.
RNA polymerase III
C.
RNA polymerase IV
D.
RNA polymerase II
【多选题】When cell excitability is reduced, which are correct in the following descriptions（ ）
A.
Upward shift of threshold potential
B.
The threshold intensity increases
C.
Downward shift of threshold potential
D.
The threshold potential and threshold intensity remain unchanged
E.
The threshold intensity decreases
【多选题】The main factors affecting the release of presynaptic membrane transmitters are（ ）
A.
Conduction velocity of the action potential
B.
Number of vesicles that release the transmitter
C.
The amount of Ca2+ entering the anterior membrane
D.
Amplitude of spike
E.
The size of the transmitter vesicle
【单选题】Which is TURE about the initiation of prokaryotic DNA replication?（ ）
A.
DNA helicase unwinds DNA duplex at oriC
B.
DNA polymerase III removes primer
C.
Topoisomerase synthesizes an RNA fragment
D.
DNA polymerse I synthesizes newly synthesized strand
【单选题】A gene has the base sequence ACCCGTGCACGT. If the A at the beginning of the sequence is deleted, what will be happen?（ ）
A.
RNA polymerase will skip that codon, and the other codons will be read normally.
B.
Only one amino acid coded for in that codon will be changed
C.
RNA polymerase will insert the correct codon, and a normal protein will be produced
D.
All of the codons after A point will be changed
【单选题】What causes dwarfism?（ ）
A.
Excessive glucocorticoid secretion
B.
Hypothyroidism in childhood
C.
Iodine deficiency in food
D.
Lack of protein in food
E.
Insufficient growth hormone secretion in childhood