Reference no: EM133292911
Question 1.
A molecule of DNA is comprised of one nucleotide strand.
True
False
Question 2.
Two species of rats belonging to the same genus occasionally mate, but the offspring fail to develop and are not born alive. What is the mechanism for keeping the two rat species separate?
The prezygotic barrier called hybrid sterility
Adaptation
Gametic isolation
The postzygotic barrier called hybrid inviability.
Question 3.
Two unrelated species evolving to look more similar due to environmental pressures is called
Transitional species
Vestigial structures
Directional selection
Convergent evolution
Question 4.
If a tRNA molecule specialized in the transfer of the amino acid valine has the anticodon CAG, with what codon will it couple?
GAC
TUG
GTC
GUC
Question 5.
Which of the following descriptions best fits the class of molecules known as nucleotides?
a nitrogenous base, phosphate group and sugar
ATP and a purine and pyridimine
a lipid, adenine and uracil
guanine, adenine, thymine and serine
Question 6.
What is the role of DNA polymerase?
Seal two DNA fragments together.
It is capable of absorbing photons of light.
It cuts DNA into smaller fragments.
Adds nucleotides to a primer to create a complementary DNA strand.
Question 7.
Different alleles for a trait can arise through a mutation in the DNA strand.
True
False
Question 8.
Natural selection is sometimes described as "survival of the fittest". Which of the following most accurately measures an organism's fitness?
How strong it is when pitted against others of its species.
Its mutation rate.
How many fertile offspring it produces.
How much food it is able to make or obtain.
Question 9.
Some snakes have reduced hind leg bones which are vestigial.
True
False