$$\text{Lower } pH \rightarrow \text{decreased } O_2$ \text{ affinity of hemoglobin}$$

Question 1

Which of the following statements best explains why proteins are considered 'essential amino acids' in the human diet?

Accepted Answer

They are amino acids that the body cannot synthesize and must be obtained from food.

Question 2

A patient is unable to digest starch efficiently. Which digestive enzyme is most likely deficient?

Accepted Answer

Amylase

Question 3

Which of the following best describes the function of the large intestine in the digestive system?

Accepted Answer

Reabsorbs water and electrolytes, forming feces

Question 4

Which adaptation would you expect to find in a carnivorous mammal compared to a herbivorous mammal?

Accepted Answer

Sharp teeth for tearing and shorter digestive tract

Question 5

In the context of gas exchange, what is the primary advantage of counter-current exchange in fish gills?

Accepted Answer

It maximizes oxygen uptake by maintaining a gradient along the entire length of the capillary.

Question 6

Which equation best represents the Bohr effect in hemoglobin oxygen transport?

Accepted Answer

$$	ext{Lower } pH ightarrow 	ext{decreased } O_2$ 	ext{ affinity of hemoglobin}$$

Question 7

A person is experiencing dehydration and their kidneys are producing concentrated urine. Which hormone is most likely elevated?

Accepted Answer

Antidiuretic hormone (ADH)

Question 8

Which part of the nephron is primarily responsible for creating a concentration gradient in the medulla, allowing for water reabsorption?

Accepted Answer

Loop of Henle

Question 9

Which of the following best describes the difference between a neuron and a nerve?

Accepted Answer

A neuron is a single nerve cell; a nerve is a bundle of many neurons.

Question 10

During an action potential, which ion's movement is primarily responsible for depolarization of the neuron membrane?

Accepted Answer

Na$$^+$$ ions moving into the cell

Question 11

Which process occurs at the neuromuscular junction to initiate muscle contraction?

Accepted Answer

Release of acetylcholine (ACh) from the neuron, binding to receptors on the muscle cell

Question 12

Which muscle type is striated and voluntary, and is attached to bones?

Accepted Answer

Skeletal muscle

Question 13

What is the role of ATP in the sliding filament model of muscle contraction?

Accepted Answer

ATP binds to myosin, causing it to detach from actin and re-energize for another contraction cycle.

Question 14

Which of the following best explains why herbivores have longer digestive tracts than carnivores?

Accepted Answer

Longer tracts allow more time and surface area for the breakdown and absorption of plant material, which is harder to digest.

Question 15

Which of the following is a nitrogenous waste product that is energetically costly to produce but conserves water?

Accepted Answer

Uric acid

Question 16

A person is exposed to a toxin that blocks voltage-gated Na$$^+$$ channels in neurons. What immediate effect would this have on nerve function?

Accepted Answer

Action potentials would not be generated, leading to loss of nerve signaling.

Question 17

Which of the following best describes the function of the distal tubule in the nephron?

Accepted Answer

Fine-tuning of salt and water balance, responding to hormones like ADH and aldosterone

Question 18

Which of the following is true regarding the oxygen saturation curve for hemoglobin?

Accepted Answer

It shows how readily hemoglobin binds/releases O$$_2 at $$different partial pressures.

Question 19

Which of the following is a correct sequence of blood flow in a fish's circulatory system?

Accepted Answer

$$	ext{Atrium} ightarrow 	ext{Ventricle} ightarrow 	ext{Gills} ightarrow 	ext{Body Tissues} ightarrow 	ext{Heart}$$

General Biology Study Notes: Digestion, Circulation, Excretion, Nerves, and Muscles

Study Guide - Practice Questions