Test 3, 5

Question 1

Each DNA nucleotide is made up of

A six-carbon sugar, a phosphate group, and one of twenty amino acids.
B five-carbon sugar, a nitrogenous base, and one of twenty amino acids.
C five-carbon sugar, a phosphate group, and one of four nitrogenous bases.
D six-carbon sugar, a nitrogenous base, and one of four amino acids.
E five-carbon sugar, a phosphate group, and one of four amino acids.

Answer 1

C

Question 2

Which of the following nucleotide sequences represents the complementary sequence that would be transcribed from the DNA 5’-GACGTT-3’?

A 5’-CUGCAA-3’
B 5’-CTGCAA-3’
C 3’-CTGCAA-5’
D 3’-CUGCAA-5’

Answer 2

D: transcription is antiparallel and complementary. in RNA, thymine (T) is replaced by uracil (U)

Question 3

Which of the following best describes the phylogenetic relationship between protists, fungi, plants, and animals?

A Fungi and animals share a common protist ancestor, while plants arose from a different protist ancestor.
B Fungi and plants share a common protist ancestor, while animals arose from a different protist ancestor.
C Animals and plants share a common protist ancestor, while fungi arose from a different protist ancestor.
D Plants, animals, and fungi each arose from a different protist lineage.

Answer 3

A : fungi have more in common with animals than plants, ex: heterotroph

Question 4

Most queen fire ants have the genotype Bb which produces a unique scent. BB queens without this scent are killed by worker ants, bb queens die before maturity. This describes an example of

A heterozygous advantage
B natural selection
C lethal recessive
D non-random mating
E too confusing to decide

Answer 4

C-B-A

Question 5

Population sizes for animals extinct in the wild are fairly small which limits the number of potential mates, and matings between relatives are likely. This is an example of

A sexual selection
B natural selection
C genetic drift
D non-random mating
E too confusing to decide

Answer 5

D: matins between closely related individuals is an example of inbreeding

Question 6

Fossil fuels are often called hydrocarbons. Oil is drilled from the bottom of the Earth, then transported across the oceans in large ships to refineries where they get transformed into the gas that you put in your car. Based on the structure of hydrocarbon molecules and concepts seen in class, explain why oil ships sinking and oil spilling into the ocean is so damaging for aquatic wildlife.

Student 1:
Based on the structure of hydrocarbon molecules and concepts seen in class, oil ships sinking and oil spilling into the ocean is so damaging for aquatic wildlife because it kills animals in the ocean. To fully understand this question, one has to know that hydrocarbons are similar to lipids in the fact that they both have a long carbon chain. However, fatty acids, in comparison, have a carboxyl group that hydrocarbons don’t have. Therefore, it is correct to say that hydrocarbons just like lipids are non-polar (as opposed to sugars, which are highly polar) because they have no oxygen molecules in their structure and because they have many hydrogen and carbon atoms. This makes them hydrophobic, which means that they don’t like the water. Because of this, oil will not dissolve in water when a ship is sinking, and the oil will float on water and will be ingested or breathed by aquatic wildlife and therefore be harmful.

Student 2:
Because hydrocarbons are long carbon chains, they are non-polar, hence hydrophobic, and will not dissolve in water. Aquatic wildlife will then ingest or inhale oil and be harmed.

Who deserves more points on this question?

Answer 6

E