Question

1. which of the following is a true statement about both dna and rna molecules?

both are always found outside of the nucleus
both have the sugar deoxyribose
they use different nitrogen bases
they are composed of the same number of strands
question 9

1. if a sequence of nitrogen bases on dna strand is t - a - g - c - c - t - a, the complementary mrna strand will be:

u - a - g - c - c - u - a
a - u - c - g - g - a - u
t - g - c - g - g - a - a
a - t - c - g - g - a - t

Explanation:

• Question 8:
• DNA is mainly in the nucleus (not always outside), RNA can be in nucleus and cytoplasm.
• DNA has deoxyribose, RNA has ribose.
• DNA has \(A - T - G - C\) bases, RNA has \(A - U - G - C\) (different nitrogen bases).
• DNA is double - stranded, RNA is usually single - stranded.
• Question 9:
• In transcription (DNA to mRNA), \(A\) pairs with \(U\), \(T\) pairs with \(A\), \(G\) pairs with \(C\), \(C\) pairs with \(G\).
• For DNA \(T - A - G - C - C - T - A\), mRNA is \(A - U - C - G - G - A - U\).

Answer:

1. They use different nitrogen bases
2. A - U - C - G - G - A - U