Question

1) The designation of the polarity of a polynucleotide strand is

Select one:

A) north – south.

B) left – right.

C) positive – negative.

D) 5’ – 3’.  

E) N – C.

2) A location on a specific chromosome that has appreciable variation in a population is called __________________________.

Select one:

A) a chromosomal arm.

B) an inherited disease.

C) a DNA polymorphism.  

D) phenotypic variation.

E) a homologue.

3) In the DNA barcoding of animals, a portion of the cytochrome oxidase 1 gene (cox-1) is used. Why?

Select one:

A) The gene sequence varies little among members of a species, but varies more among different species.

B) The cox-1 gene encodes surface features of animals, allowing their identities to be established by visual inspection.

C) There is little variability in the cox-1 gene among different animal species, so the gene is a reliable marker of “animalhood”.

D) The sequences flanking the cox-1 gene are different in different animal species.

E) The cox-1 gene is found in some animals, but not in others.

Answer 1

1. A chain of nucleotides join to form a polynucleotide strand. These polynucleotide strands are part of DNA or RNA. A DNA or RNA has two polarity. It can be either 5' to 3' or 3' to 5. The template strand has 3' to 5' polarity, while the RNA has 5' to 3' polarity.

The answer is D.