Cell Biology Answers

The Ras protein functions as a molecular switch that is set to its “on” state by other proteins that cause it to release its bound GDP and bind GTP. A GTPase-activating protein helps reset the switch to the “off” state by inducing Ras to hydrolyze its bound GTP to GDP much more rapidly than it would without this encouragement. Thus, Ras Works like a light switch that one person turns on and another turns off. You are studying a mutant cell that lacks the GTPase-activating protein. What abnormalities would you expect to find in the way in which Ras activity responds to extracellular signals?

Testosterone in humans shapes the formation of the external genitalia and influences brain development in the fetus; at puberty, the hormone triggers the development of male secondary sexual characteristics.

Assume that you are a genetic counsellor and you have a case who is genetically male but developed as a female. What could be the defect in this case? How would you explain the situation to the case?

Please explain the refulation of dynamic structure of microtubules?

The events which occur in both mitosis and meiosis are similar except during

• The first interphase

• chromosomal duplications

•none of these choices

•anaphase

A skin cell of a mouse has 22 chromosomes. How many chromosomes would you expect to find in

a) an unfertilized egg cell of a mouse

b) A zygote of a mouse

Embryonic stem cells are cells derived from an embryo. These cells can be used to create new tissues for patients suffering from certain illnesses and disorders. Which statement best summarizes why the use of embryonic stem cells could be seen as unethical?

Name two similarities and two differences between the cellular processes of importing protein into the ER and importing protein to the nucleus.

Explain the role of the Endoplasmic Reticulum in protein folding. Consider quality control, the solutions to folding and refolding, and the degradation of proteins.

A patient com

A patient comes into your clinic with unexplained paralysis in her limbs. She has no history of neuromuscular problems. After further questioning you find that that she had taken a drug “X.” Explain the effect of a possible toxin in the drug on actin filaments that might be the cause of her paralysis.

Using an example, explain why it is necessary to determine the genotypes of the gametes of the mated individuals in order to predict the phenotypes of their offspring.