UNIVERSITY OF THE FREE STATE
BLGY 2625
DEPARTMENT: ZOOLOGY and ENTOMOLOGY
SEMESTER TEST 2
26 September 2023
ASSESSOR:
MODERATOR:
TIME: 1 hour
L Heyns
Prof JPH Pretorius
MARKS: 50
Answer all questions.
QUESTION 1 [15]
1.1 Why is it necessary for animals to possess endocrine and nervous systems?
(3)
1.2 Differentiate between autocrine and paracrine chemical messengers.
(2)
1.3 How do neurotransmitters and hormones differ?
(2)
1.4 Critique the statement: "Hormones are not continuously secreted for them to be effective." (3)
1.5 Using an example, explain how negative feedback regulates hormone levels within the mammalian endocrine system.
rahtA
Left ex
right
Lee U
B
QUESTION 2 [18]
2.1 What are the physiological advantages of having separate ventricles in birds and mammals? (5)
22 List the major mammalian heart valves and their locations. Furthermore, explain their function within the circulatory system.
(5)
2.3 Compare the structure and function of arteries, veins, and capillaries in the circulatory system. (8)
QUESTION 3 [17]
3.1 Define and explain the concept of "resting membrane potential" in neurons. (4)
3.2 Describe the process of action potential generation and propagation in neurons. (5)
3.3 How does the myelin sheath and nodes of Ranvier aid in the conduction of nerve impulses? (4)
QUESTION 4 [16]
4.1 Explain the three types of muscle tissue found in the human body. (6)
4.2 Compare skeletal muscle contraction with smooth muscle contraction in terms of structure, control, and function. (6)
4.3 Discuss the role of calcium ions in muscle contraction. (4)
QUESTION 5 [12]
5.1 Define and compare osmosis, diffusion, facilitated diffusion, and active transport. (8)
5.2 How do these processes contribute to maintaining cellular homeostasis? (4)