Critical Thinking Questions

23.
How does an asymmetrical body plan differ from radial or bilateral body plans?
  1. Asymmetrical organisms can produce equal halves if cut along a certain plane, whereas radially and bilaterally symmetric organisms have no distinct pattern.
  2. Asymmetrical organisms have no distinct pattern, whereas radially and bilaterally symmetric organisms can produce equal halves if cut along a certain plane.
  3. Asymmetrical organisms produce equal halves if cut along a certain plane with no definite right or left side, whereas radially and bilaterally symmetric organisms can produce equal halves.
  4. Asymmetrical organisms produce equal halves if cut along a certain plane with definite right and left sides, whereas radially and bilaterally symmetric organisms can produce equal halves.
24.
Why are most organisms with exoskeletons relatively small?
  1. Increases in body weight increase body size by a factor of eight, and the chitin thickness of the exoskeleton has to significantly decrease to accommodate increase in body size.
  2. Doubling of body size increases body weight by a factor of eight, and the chitin thickness of the exoskeleton has to significantly decrease to accommodate weight increase.
  3. Increases in body weight increase body size by a factor of eight, and the chitin thickness of the exoskeleton has to significantly increase to accommodate increase in body size.
  4. Doubling of body size increases body weight by a factor of eight, and the chitin thickness of the exoskeleton has to significantly increase to accommodate weight increase.
25.
What is the relationship between basal metabolic rate (BMR) and body size? Why?
  1. BMR decreases with body size, because larger animals require more energy to maintain their size. However, smaller animals have relatively higher BMRs per body weight because they have greater surface area.
  2. BMR increases with body size, because smaller animals require more energy to maintain their size. However, larger animals have relatively higher BMRs per body weight because they have greater surface area.
  3. BMR increases with body size, because larger animals require more energy to maintain their size. However, smaller animals have relatively higher BMRs per body weight because they have greater surface area for their mass.
  4. BMR decreases with body size, because smaller animals require more energy to maintain their size. However, larger animals have relatively higher BMRs per body weight because they have greater surface area for their mass.
26.
Radial symmetry is typically found in aquatic organisms. What is radial symmetry and why is it advantageous to certain aquatic organisms?
  1. Radially symmetric means that a plane cut from the front to back of the organism produces distinct left and right sides that are mirror images of each other. It helps certain aquatic organisms to extract food from surrounding environments.
  2. Radially symmetric means that a plane cut from the front to back of the organism produces distinct left and right sides that are mirror images of each other. It helps certain aquatic organisms to perform photosynthesis.
  3. Radially symmetric means that a plane cut along its longitudinal axis will produce equal halves, and there is no distinct left or right. It helps certain aquatic organisms to perform photosynthesis.
  4. Radially symmetric means that a plane cut along its longitudinal axis to produce equal halves, and there is no distinct left or right. It helps certain aquatic organisms to extract food from surrounding environments.
27.
Columnar epithelial cells, which are typically found in a single-layer arrangement, are found along the digestive tract. What is the role of columnar epithelial cells in digestion?
  1. Columnar epithelial cells absorb material from the lumen of the digestive tract to prepare the material for entry into the body.
  2. Columnar epithelial cells release mucus for lubrication as well as antimicrobial agents in the digestive tract.
  3. Columnar epithelial cells secrete enzymes like salivary amylase which aid in digestion by the breakdown of carbohydrates in the body.
  4. Columnar epithelial cells help in the propulsion of food by peristalsis in the digestive tract of the body.
28.
In vertebrates, cartilage is found in fetal bones, ears, and intervertebral discs, whereas bone is found in the skeleton. What are the similarities between cartilage and bone?
  1. Both are types of connective tissue in the body and cells of both are known as chondrocytes.
  2. Both are types of connective tissue in the body and have non-vascular organic matrix material that provides strength and flexibility.
  3. Both are types of connective tissue in the body and have organic matrix material that provides strength and flexibility.
  4. Both consist of bone marrow and have organic matrix material that provides strength and flexibility.
29.
A friend sneaks up behind you and scares you, speeding up your heart rate. How and why did this event influence cardiac muscle contraction?
  1. Muscle contraction speed increases as the enteric nervous system responds to local conditions and makes muscle contraction speed up or slow down.
  2. Muscle contraction speed increases as the autonomic nervous system responds to local conditions and makes muscle contraction speed up or slow down.
  3. Muscle contraction speed increases as the somatic nervous system responds to local conditions and makes muscle contraction speed up or slow down.
  4. Muscle contraction speed increases as the central nervous system responds to local conditions and makes muscle contraction speed up or slow down.
30.
Neurons have several specialized structures, including dendrites. What might happen if an individual has malformed dendrites?
  1. The individual’s neurons would not be able to receive input properly.
  2. The individual’s neurons would not be able to synthesize proteins.
  3. The individual’s neurons would not be able to communicate with target neurons.
  4. The individual’s neurons would not be able to carry nerve signals.
31.

How can squamous epithelia, which have a high surface area-to-volume ratio, both facilitate diffusion and prevent damage from abrasion?

  1. Single layers of squamous epithelia facilitate gas, nutrient, or waste exchange, whereas stratified layers provide protection but are not replaceable following damage.
  2. Stratified layers of squamous epithelia facilitate gas, nutrient, or waste exchange, whereas single layers provide protection and are replaceable following damage.
  3. Single layers of squamous epithelia facilitate gas, nutrient, or waste exchange whereas stratified layers provide protection and are replaceable following damage.
  4. Single layers of squamous epithelia facilitate only exchange of gases by diffusion, whereas stratified layers provide protection and are replaceable following damage.
32.
What is homeostasis and how does it help maintain equilibrium of various body functions throughout the body?
  1. Homeostasis is the process of achieving stability, which occurs through behavioral changes. Equilibrium is maintained by that ensuring body functions remain within a certain range.
  2. Homeostasis is the process by which constant adjustments to changes in the body occur, and equilibrium is maintained by ensuring that body functions remain within a certain range.
  3. Homeostasis is the process that prevents blood loss from circulation when a blood vessel is ruptured, and equilibrium is maintained by ensuring that circulation of blood is kept within a normal range.
  4. Homeostasis is the process by which constant adjustment to changes in the body occurs, and equilibrium is maintained as body functions remain within a certain range without any fluctuations.
33.

How can an environmental change result in an alteration of gland secretion?

  1. A receptor detects change and sends a signal to the control center, which sends a signal to the gland to inhibit the gland secretions.
  2. A receptor detects change and sends a signal to the control center, which sends a signal to the gland to increase the secretions of the gland.
  3. A receptor detects change and sends a signal to the effector directly, which, in this case, is the gland.
  4. A receptor detects change and sends a signal to the control center, which in turn sends a signal to the effector, which, in this case, is the gland.
34.

How is a condition such as diabetes a good example of the failure of a set point in humans?

  1. A negative-feedback loop cannot proceed in diabetic individuals, as they do not produce enough functional insulin to lower blood sugar.
  2. Negative-feedback loop cannot proceed in diabetic individuals, as they do not produce enough functional insulin to increase the blood sugar.
  3. Positive-feedback loop cannot proceed in diabetic individuals, as they do not produce enough functional insulin to lower blood sugar.
  4. Positive-feedback loop cannot proceed in diabetic individuals, as they do not produce enough functional insulin to increase the blood sugar.
35.

What are the roles of vasodilation and vasoconstriction in maintaining body temperature?

  1. Vasodilation allows for radiation and evaporative heat loss, and vasoconstriction brings blood to the core to conserve heat by vital organs.
  2. Vasodilation brings blood to the core to conserve heat by vital organs, and vasoconstriction results in radiation and evaporative heat loss.
  3. Vasodilation results in the formation of an insulating layer between skin and internal organs, causing heat conservation and brings blood to the core to conserve heat.
  4. Vasodilation results in radiation and evaporative heat loss, and vasoconstriction transfers heat from arteries to veins to warm blood returning to the heart.