Practice Exam 1 Incorrect Answers

Question 1

What is the role of antibodies?

Answer 1

To detect and remove foreign antigens or attack specific bacteria and viruses.

Question 2

What is the role of insulin in regulating metabolism?

Answer 2

When insulin is present, it enhances cells ability to take in glucose as energy. If there is sufficient energy, insulin tells the liver to take up glucose and store it as glycogen.

Question 3

What’s a point mutation?

Answer 3

A mutation in which one or very few nucleotides in a sequence is affected. Since the frame is not shifted in any way, this is usually a minute issue.

Question 4

What is nondisjunction?

Answer 4

The failure of homologous chromosomes to separate during meiosis.
*Can occur during Meiosis I or Meiosis II

Question 5

Which stage during embryonic development would we not expect differentiation?

Answer 5

Division at the one cell stage. This stage is indeterminate, while all other stages undergo determinate cell division.

Question 6

How many hydrogen bonds do Guanine (G) and Cytosine (C) form?

Answer 6

3

Question 7

What is recombination frequency, and what does it measure?

Answer 7

Recombination frequency is a measure of the genetic difference between genes, not the actual physical difference.
*It’s the likelihood (frequency, number of times per division) that recombination will occur

Question 8

What are the different levels of CentiMorgans and what do each tell about inheritance probabilities?

Answer 8

*Look up

Question 9

Which alleles have the highest recombination frequencies?

Answer 9

Alleles that are furthest apart

Question 10

What structure types stem from the ectoderm?

Answer 10

External layers of the body. This includes epidermis layer of skin, neurons of brain, and pigment cells.

Question 11

How does the lac operon work?

Answer 11

When allolactose (inducer) is present, the represser (ie lac operon) binds to the inducer, freeing up the operator and RNA polymerase to transcribe the desired protein. When the inducer is absent, the repressor binds to the operator, preventing RNA polymerase from transcribing the eukaryotic genes.

Question 12

Where do microtubules attach to on chromosomes?

Answer 12

Centromeres

*look up other structural aspects of the chromosome

Question 13

What are the basic amino acids at ph 7.4? (hint, give a positive charge)

Answer 13

Arginine and lysine, and somewhat histidine - look up histidine’s pKa

Question 14

What are the acidic amino acids at ph 7.4? (hint: they give a negative charge)

Answer 14

Aspartic acid and glutamic acid

Question 15

At what phase in mitosis do tubulin polymers shorten?

Answer 15

Anaphase - when the chromosomes are pulled towards the two poles of the cell.
*Look up phases of Mitosis and Meiosis

Question 16

What does isoosmotic mean? What implication does this have on net movement between two fluids?

Answer 16

Isoosmotic means that the target fluid has the same concentration of particles as whatever its being compared to.
AKA: osmotic pressure is constant. Iso = constant, osmotic = osmotic pressure

Therefore, the same osmotic pressure exists on either side of the membrane, creating no net movement of water between the two substances (ie blood and dialyzing fluid)

Question 17

What are self-splicing introns?

Answer 17

Introns that do not involve protein enzymes in their splicing reactions.

Question 18

What structures are formed from the endoderm?

Answer 18

Epithelial linings of the digestive and respiratory tracts (includes lungs), parts of liver, pancreas, thyroid, and bladder.

Question 19

What structures are formed from the mesoderm?

Answer 19

Muscle, connective tissue, cartilage, bone, lymphoid tissue, and circulatory system.