Bio

Question 1

Which muscle fiber subtypes have high mitochondrial density + high capillary density?

Answer 1

Type I (slow twich) and Type IIa (intermediate)

Question 2

In order for a developing T lymphocyte to become activated and enter into circulation, it must be able to:

Answer 2

Recognize a self-MHC and not become activated by a self-antigen

Question 3

In order for a bacteriophage (virus) to infect a wider range of bacteria, what viral genes need to be changed?

Answer 3

Tail fibers (identifies and infects host)

Question 4

Why do infants have more brown fat than adults?

Answer 4

The electron transport chain is less efficient (releases more heat as fuel is burned)
Infants cannot shiver
A greater surface area to volume ratio makes them more susceptible to the cold

Question 5

What structures arise from the mesoderm?

Answer 5

Musculoskeletal, circulatory, most excretory systems, the gonads, and the adrenal cortex

Question 6

What is the normal pH of blood?

Answer 6

Around 7.35 to 7.45

Question 7

Which of the following contains an RNA replicase enzyme?
DNA virus
Retrovirus 
Negative-sense RNA virus
Positive-sense RNA virus

Answer 7

Negative-sense RNA virus (the RNA acts as a template for synthesis of a complementary strand, need RNA replicase to make sure complementary strand is synthesized)

Question 8

Why might damaged nerves repair relatively slow?

Answer 8

A relative lack of ribosomes in the axons (they are located in the soma) means that new proteins must be transported large distances

Question 9

What is expressivity?

Answer 9

People with the same gene/mutation show different phenotypes (one gets cancer while another one has a different hair color)

Question 10

What is penetrance?

Answer 10

Is a population measure defined as the proportion of individuals in the population carrying the allele who actually express the phenotype