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Quick Biochemistry - Nucleic Acids (Section 10)

1
What is the approximate maximum size of DNA sequences that can be amplified using a yeast artificial chromosome?
Answer
(D)
Up to 1,000 kb
2
The basis of DNA fingerprinting relies on the presence of which of the following in DNA?
Answer
(B)
Variable number of tandem repeats
3
Which statement about restriction fragment length polymorphism is NOT accurate?
Answer
(D)
It can be used to diagnose any genetic disease
4
Inborn errors of the urea cycle can lead to all of the following EXCEPT:
Answer
(D)
Mental retardation
5
Hyperammonemia type I is caused by a congenital deficiency of which enzyme?
Answer
(B)
Carbamoyl phosphate synthetase
6
What condition is caused by a congenital deficiency of ornithine transcarbamoylase?
Answer
(C)
Hyperornithinaemia
7
Which of the following amino acids is considered ketogenic?
Answer
(A)
Leucine
8
The carbon skeleton of which amino acid(s) can be used for gluconeogenesis?
Answer
(D)
All of these
9
N-Formiminoglutamate is a metabolite of which amino acid?
Answer
(B)
Histidine
10
Methylmalonyl CoA is a metabolite of which amino acid?
Answer
(A)
Valine
11
What molecule is a precursor to homogentisic acid?
Answer
(C)
Tyrosine
12
What metabolic disorder is associated with a lack or significant deficiency of a specific enzyme?
Answer
(D)
None of these
13
What serves as a targeting signal in lysosomal enzymes?
Answer
(C)
Galactose-6-phosphate
14
A genetic disorder affects which structural protein, causing Marfan's syndrome?
Answer
(B)
Elastin
15
Which of the following is NOT accurate regarding fibronectin?
Answer
(A)
It is a glycoprotein
16
Fibronectin interacts with all the following EXCEPT:
Answer
(C)
Heparin
17
Which cellular processes involve fibronectin?
Answer
(B)
Cell movement
18
How are glycoproteins targeted for degradation?
Answer
(D)
N-terminal amino acids
19
Glycophorin is found in the cell membranes of which type of cells?
Answer
(A)
Erythrocytes
20
What type of molecules do selectins specifically recognize?
Answer
(A)
Carbohydrates
21
What is the primary cause of Hunter's syndrome?
Answer
(B)
Iduronate sulphatase deficiency
22
Which of the following is a key characteristic of a cancerous cell?
Answer
(D)
Uncontrolled cell division
23
If the genetic material of a cancerous cell is introduced into a normal cell, what is the likely outcome for the recipient cell?
Answer
(D)
Becomes a cancerous cell
24
A normal cell can transform into a cancerous cell through which of the following methods?
Answer
(C)
Exposure to oncogenic bacteria
25
Where are proto-oncogenes typically found?
Answer
(C)
Normal human cells
26
Which statement about proto-oncogenes is incorrect?
Answer
(D)
They are only expressed when a normal cell becomes cancerous
27
Oncogenes might code for all of the following except:
Answer
(A)
Non-carcinogenic substances
28
How is the Ras proto-oncogene typically converted into an oncogene?
Answer
(A)
Through a point mutation
29
What does the Ras proto-oncogene produce?
Answer
(C)
Signal transducer for EGF
30
What is the function of the P 53 gene?
Answer
(C)
It is a tumor suppressor gene
31
A genetic change causing retinoblastoma occurs in which gene?
Answer
(D)
RB 1 gene
32
Which statement about retinoblastoma is incorrect?
Answer
(D)
The RB 1 gene contributes to retinoblastoma development
33
The Ames assay is used to quickly identify
Answer
(C)
Chemical substances causing cancer
34
When a cancer cell increases the number of copies of the dihydrofolate reductase gene, the cell becomes
Answer
(C)
Unaffected by amethopterin treatment
35
What process often transforms a substance that can cause cancer into an active carcinogen?
Answer
(B)
A specific chemical reaction
36
Which of the following is an accurate description of oncoviruses?
Answer
(D)
Oncoviruses can be either DNA or RNA viruses
37
The RB 1 gene functions as
Answer
(A)
A gene that prevents tumors
38
What mechanism could allow cancer cells to avoid the effects of amethopterin?
Answer
(B)
Increasing the number of copies of the dihydrofolate reductase gene
39
The primary source of ammonia produced by the kidney is
Answer
(D)
Glutamine
40
Which of these compounds is not a quarternary ammonium compound involved in donating methyl groups?
Answer
(A)
Methionine
41
What enzyme catalyzes the oxidative deamination of L-glutamic acid?
Answer
(B)
L-glutamate dehydrogenase
42
A prokaryotic ribosome is composed of which subunits?
Answer
(B)
30S and 50S
43
What subunits make up a eukaryotic ribosome?
Answer
(A)
40S and 60S
44
In which of the following processes is GTP NOT essential?
Answer
(D)
Formation of the tRNA amino acid complex
45
Which antibiotic specifically interferes with DNA-dependent RNA polymerase activity?
Answer
(B)
Actinomycin d
46
Which antibiotic is known to cause DNA cleavage?
Answer
(D)
Mitomycin C
47
Which antibiotic's structure resembles the aminoacyl end of tRNA-tyrosine?
Answer
(C)
Puromycin
48
In which process is ATP a required component?
Answer
(D)
Formation of the tRNA amino acid complex
49
Where within a cell does protein synthesis primarily occur?
Answer
(C)
Ribosomes
50
When would an animal be considered to be in a state of negative nitrogen balance?
Answer
(C)
Output exceeds intake