What would be the result of a cytosine base being
substituted for a thymine base in a DNA segment during
DNA replication? (1 point)
The entire segment of DNA would be
affected.
The cytosine base would pair with adenine
when the DNA was replicated.
There would be no effect on the DNA.
The sequence could code for the wrong
amino acid during translation
The cytosine base would pair with adenine when the DNA was replicated.
What would be the result of a cytosine base being
substituted for a thymine base in a DNA segment during
DNA replication? (1 point)
The entire segment of DNA would be
affected.
The cytosine base would pair with adenine
when the DNA was replicated.
There would be no effect on the DNA.
The sequence could code for the wrong
amino acid during translation
The cytosine base would pair with adenine when the DNA was replicated.
Which statement is the first step of protein synthesis?
(1 point)
tRNA carries amino acids to the ribosome
and attaches them to the mRNA strand.
A ribosome attaches to the mRNA.
Amino acids are linked together with
peptide bonds.
DNA unzips between the base pairs
DNA unzips between the base pairs.
Which statement is true? (1 point)
The human body uses 20 amino acids to
form all types of proteins.
Amino acids do not need to be assembled
in a particular order.
Amino acids form a polypeptide chain via
carbon-carbon bonds.
tRNA is attached to specific proteins in the
cell’s cytoplasm.
The human body uses 20 amino acids to
form all types of proteins.
Hemophilia is a hereditary bleeding disorder that
primarily affects males. In 3–5 sentences, summarize
why this condition typically affects males more than
females. (4 points)
Hemophilia typically affects males more than females because it is an X-linked recessive disorder. The gene responsible for hemophilia is located on the X chromosome. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY). If a male inherits a faulty hemophilia gene on his X chromosome, he does not have a second X chromosome to compensate for the defective gene. In contrast, females have two X chromosomes and can inherit a normal gene on one X chromosome, which can compensate for the defective gene on the other X chromosome. Therefore, females are more likely to be carriers of the hemophilia gene, while males are more likely to actually have the disorder.
The lactose (lac) operon in E. coli is an example of a
gene that is repressed when lactose is not available in
a cell. In 3-5 sentences, explain what this means, using
correct terminology. (4 points)