Question

22) Which of the following is true?
A. Cells transcribe and translate every gene they have, but only activate proteins that they need.
B. All cells in your body have the same DNA, but cells function differently because they turned on
only certain genes needed for that cell’s job.
C. Mature cells have different DNA because they only carry the genes they need for their job.
D. Cells transcribe every gene they have, but only translate those that they need.

23) Athletes who abuse anabolic steroids often demonstrate different effects such as muscle growth, loss of libido and aggression. How can this be explained at the cellular level?
    A. Testosterone is a repressor of genes controlling these traits.
    B. Testosterone binds to different receptors and turns on a variety of genes controlling the traits.
    C. Testosterone adds a methyl group to the DNA turning genes on.
    D. Testosterone blocks enzymes which control these traits.

24) Which of the following supports the argument that viruses are nonliving?
A. They are not cellular.        B. They do not evolve.    C. They lack genetic material.
D. They have RNA rather than DNA.        E. Their DNA does not encode proteins

Answer 1

Question 22

Solution: All cells in your body have the same DNA, but cells function differently because they turned on
only certain genes needed for that cell’s job.

Because of differential expression of genes. Content and composition of DNA in the cell are the same. However, they turned on only certain genes needed. This is called  differential expression of genes

• Cells do not transcribe and translate every gene they have and they do not have any such mechanism to activate proteins that they need
• Mature cells do not have different DNA. DNA composition of all the cells are same and cells carry all the the genes. But theur expression is different
• Cells do not transcribe all the genes they have. Cells transcribe only the genes that they need

Question 23

Solution Option B- Testosterone binds to different receptors and turns on a variety of genes controlling the traits.

anabolic steroids mimics the male sex hormone Testosterone and result in the activation of genes related to muscle growth, loss of libido and aggression. Testosterone is not a repressor of genes controlling these traits, it is an activator.Testosterone do not cause any methylation to the DNA. Methylation generally turn the genes of. Testosterone do not blocks enzymes which control these traits, instead it activate enzymes

Question 24

Solution - Option A. They are not cellular

• Viruses are able to evolve(eg. pathogenic virus evolve to adapt to the changes in host immunity).
• Viruses contain either RNA or DNA as genetic material.
• DNA of virus are capable of encoding proteins.