let's continue with these questions.
39. Which endocrine gland controls the basal metabolic rate?
The thyroid gland produces hormones that regulate the body's metabolism.
40. When a rhesus-negative man receives a blood transfusion from a rhesus-positive woman:
A rhesus-negative person lacks the Rh D antigen. If exposed to Rh-positive blood, their immune system will produce antibodies against the Rh D antigen.
- C. rhesus antibodies will be produced which will cause agglutination of the donor's red blood cells.
41. Which of the following growth substances level increases during the process of vernalization?
Vernalization is the induction of a plant's flowering process by exposure to prolonged cold. Gibberellins are plant hormones known to promote flowering, especially after vernalization.
For questions 42 to 50, evaluate the two statements and choose:
- A: if both statements are true and the second explains the first.
- B: if both statements are true but the second does not explain the first.
- C: if the first statement is true and the second is false.
- D: if the first statement is false and the second is true.
42.
- First Statement: It is normal for the foramen ovale of the heart to close at birth. (True)
- Second Statement: Lungs do not function as a gaseous exchange surface before birth. (True)
The foramen ovale allows blood to bypass the non-functional fetal lungs. Its closure at birth is directly related to the lungs becoming functional.
- A
43.
- First Statement: Movements of the oval window causes similar movements of the perilymph and endolymph within the cochlea. (True)
- Second Statement: Pressure waves of the perilymph and endolymph cause the hair cells of the organ of corti to pull against the tectorial membrane. (True)
The vibrations transmitted through the oval window create pressure waves in the cochlear fluids, which then stimulate the hair cells against the tectorial membrane, leading to sound perception.
- A
44.
- First Statement: Hypothermia is a condition that occurs when core body temperature drops below 35°C. (True)
- Second Statement: Crude oil causes the matting of feathers in aquatic birds, making flight impossible leading to death. (True)
Both statements are factually correct, but the second statement does not explain the first.
- B
45.
- First Statement: Reverse transcriptase converts mRNA into complementary DNA molecules. (True)
- Second Statement: Reverse transcriptase is an enzyme found in retroviruses. (True)
Both statements are true. Reverse transcriptase's function is to synthesize DNA from an RNA template, and it is characteristic of retroviruses. However, the second statement describes where it is found, not why it performs the conversion.
- B
46.
- First Statement: Fungi cell walls are made of chitin. (True)
- Second Statement: Fungi are autotrophic organisms. (False)
Fungi are heterotrophic, meaning they obtain nutrients from external sources, unlike autotrophs which produce their own food.
- C
47.
- First Statement: A person with a faulty pituitary gland fails to produce enough ADH. (True)
- Second Statement: ADH cause the walls of the renal tubules to remain impermeable to water. (False)
ADH (Antidiuretic Hormone) increases the permeability of renal tubules to water, promoting water reabsorption.
- C
48.
- First Statement: The corpus allatum of an insect produces the hormone called juvenile hormone. (True)
- Second Statement: Juvenile hormones influence the formation of new cuticle to produce larval body forms. (True)
Juvenile hormone, produced by the corpus allatum, is crucial for maintaining the larval stage during insect development.
- A
49.
- First Statement: Stratified squamous epithelium is made up of a single layer of flattened cells attached to a basement membrane. (False)
- Second Statement: Epithelial tissues are derived from three embryonic germ layers namely ectoderm, mesoderm and endoderm. (True)
Stratified squamous epithelium consists of multiple layers of cells. Simple squamous epithelium has a single layer.
- D
50.
- First Statement: The absorption of calcium and phosphorus into the body will require vitamin D. (True)
- Second Statement: Vitamin D is a water-soluble vitamin important for the formation of bones and teeth. (False)
Vitamin D is a fat-soluble vitamin, not water-soluble.
- C
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