طلب حلول الوراثة 221 مراجعة الفاينل

[1990meme]

-The nitrogenous base is attached to which carbon of the pentose sugar? 1
a- 5' b-3' c-1'
2. DNA is a polymer of:
a-nucleosides
b-fatty acids
c- nucleotides
3. A nucleic acid was analyzed and found to contain 32 percent A, 18 percent G, 17 percent C, and 33 percent T. The nucleic acid must be:
a-single-stranded RNA
b-single-stranded DNA
c-double-stranded DNA
4-A bacteriophage is a
a- virus that infects a bacterium
b- bacterium that infects a virus
c- particle made up of bacterial nucleic acid surrounded by bacterial protein

5- In double stranded DNA how do the four bases (C,A,T,G) pair up with each other.
a-C always pairs with T and A always pairs with G
b-A always pairs with T and C and G always pair with themselves
c-A always pairs with T and C always pairs with G
6- Which of the following enzymes is not as involved in DNA replication as the others?
a-Helicase b-DNA Polymerase c-Phosphatase
a-True B) False

7- The two sides of the double helix structure of DNA are held together with hydrogen bonds.

a- True B) False

7-DNA replication is called semiconservative because half of each of the two new strands of DNA is "old" DNA from the original DNA molecule and half is "new" DNA.

A)True B) False

8-A point mutation that changes a codon specifying an amino acid into a stop codon is called a
a) missense mutation
B) nonsense mutation
c) frameshift mutation

9-The nucleic acid sequence in mRNA is determined by
A) a-the order of amino acids in the protein
B) b-nucleotide sequence in DNA
C) c-nucleotide sequence in t-RNA


10-A nucleotide deletion in DNA replication
a) causes all of the amino acids of the protein to be incorrect

b) causes the amino acids inserted after the deletion to be incorrect

c-has no effect on the resulting protein

11-The trp operon consists of ________ structural genes.


12-In the absence of tryptophan, the trp repressor is
a) inactive and cannot bind to the promoter.
b-inactive and cannot bind to the operator.
c-active and cannot bind to the operator.
13-When glucose is present
a)cyclic AMP is high, the catabolite activator protein (CAP) binds to the activator binding site, and tranion of lactose is turned on
b)cyclic AMP is low, CAP binds to the site activator binding site, and tranion of lactose is turned on
c)cyclic AMP is low, CAP does not bind to the activator binding site, and tranion is turned off