Tasks 8-9; Universal Genetic Code and Meiosis

Which of the following represent the correct complementary pairs of nucleotides found in DNA?

• A+G, T+C

• A+C, T+G

• A+T, G+C

How many nucleotides does it take to make a codon?

• 2

• 3

• 4

• 5

• 6

In RNA, which nucleotide is present instead of thymine?

• adenine

• Guanine

• Thymine

• Uracil

• Cytosine

Reorder the following steps in protein synthesis.

• The messenger RNA sequence is read and codons are used to identify amino acids.

• A DNA sequence is read and a complementary messenger RNA sequences produced.

• The long chain of amino acids is completed and becomes a protein.

• Amino acids are gathered together into a long chain.

Why is the code in DNA considered to be universal?

• RNA is used to make proteins and these proteins do work in all cells.

• DNA and the way it is used to make a protein are the same in virtually all life forms.

• DNA is found all over the world in all kinds of organisms.

• Cells with a nucleus have DNA and the DNA has codons.

Click on the amino acid name for mRNA codon AAA.

Click on the amino acid name for DNA codon AAA.

With regard to protein synthesis, what might happen if one nucleotide in DNA mutates? Mark all correct answers.

• The same amino acid could still be produced, resulting in a code mutation, but no difference in the protein.

• A different amino acid could be produced, resulting in a good mutation in the protein.

• A different amino acid could be produced, resulting in a bad mutation in the protein.

What population-level changes might occur overtime due to genetic mutations?

• Genetic mutations only affect individuals, not populations

• Only good genetic mutations can be passed on to offspring, providing the offspring with the same benefits of the mutation.

• Both good and bad genetic mutations can be passed on to offspring, providing the offspring with the same benefits or problems of the mutation.

Label each stage with its description.

a

b

c

d

the cell is growing

The cell prepares to divide

DNA is copied

the cell divides