POST UTME JOSEPH AYO BABALOLA UNIVERSITY 2018 Biology | Objective

Practice these randomly selected questions to test your readiness.

Question 1
A patient with a rare genetic disorder has a mutation in the gene encoding the protein cystic fibrosis transmembrane conduc\tance regulator (CFTR). Which of the following statements best describes the relationship between CFTR and the regulation of chloride ion transport across epithelial cell membranes?
A. CFTR is a chloride channel that regulates the transport of chloride ions across epithelial cell membranes
B. CFTR is a regulatory subunit of the epithelial sodium channel and inhibits its activity
C. CFTR is a structural component of the tight junctions between epithelial cells and provides mechanical stability
D. CFTR is a signaling molecule that interacts with the epithelial sodium channel to regulate sodium ion transport
Question 2
A 0.5 M solution of HCl is mixed with a 0.5 M solution of NaOH. What is the pH of the resulting solution?
A. 1.0
B. 2.0
C. 3.0
D. 4.0
Question 3
The process of mitosis involves the replication of DNA and the separation of chromosomes. What is the term for the stage of mitosis where the chromosomes are condensed and attached to the spindle fibers?
A. Prophase
B. Metaphase
C. Anaphase
D. Telophase
Question 4
A 35-year-old man presents with a 2-year history of erectile dysfunction. His physical examination is unremarkable. What is the most likely cause of his condition?
A. Diabetes mellitus
B. Hypertension
C. Hyperlipidemia
D. Smoking
Question 5
A 2-year-old child is brought to the pediatrician with a complaint of frequent urination. The child's urine is dark yellow and has a strong odor. Which of the following is the most likely cause of this condition?
A. Diabetes mellitus
B. Diabetes insipidus
C. Kidney stones
D. Urinary tract infection
Question 6
The xylem sap of a plant contains 0.5 M sucrose and 0.2 M glu\cose. What is the total concentration of solutes in the xylem sap?
A. 0.7 M
B. 0.8 M
C. 0.9 M
D. 1.0 M
Question 7
In the context of hormonal coordination, what is the primary function of the hypothalamus in regulating the pituitary gland?
A. To produce hormones that stimulate the pituitary gland
B. To inhibit the production of hormones by the pituitary gland
C. To regulate the release of hormones by the pituitary gland
D. To produce hormones that inhibit the pituitary gland
Question 8
A 2.5 L solution contains 0.5 M NaCl. What is the number of moles of NaCl in the solution?
A. 1.25
B. 1.25
C. 1.25
D. 1.25
Question 9
In a population of Drosophila melanogaster, the frequency of the recessive allele 'a' is 0.2. If the population is in Hardy-Weinberg equilibrium, what is the frequency of the homozygous dominant genotype 'AA'?
A. 0.64
B. 0.36
C. 0.16
D. 0.84
Question 10
A researcher is studying the effects of a new compound on the activity of the enzyme acetylcholinesterase. Which of the following statements best describes the mechanism by which the compound inhibits the enzyme?
A. The compound binds to the active site of the enzyme and prevents substrate binding
B. The compound binds to a allosteric site on the enzyme and reduces its activity
C. The compound forms a covalent bond with the enzyme and irreversibly inhibits it
D. The compound increases the activity of the enzyme by stabilizing its conformation
Question 11
A 25-year-old man is brought to the emergency room with a severe headache and vomiting. The patient's blood pressure is 180/120 mmHg. Which of the following is the most likely cause of this patient's condition?
A. Subarachnoid hemorrhage
B. Intracerebral hemorrhage
C. Hypertensive crisis
D. Meningitis
Question 12
A researcher is studying the effects of a new compound on the activity of the enzyme cytochrome P450. Which of the following statements best describes the mechanism by which the compound induces the expression of the cytochrome P450 gene?
A. The compound binds to the aryl hydrocarbon receptor and activates its transcriptional activity
B. The compound binds to the pregnane X receptor and activates its transcriptional activity
C. The compound forms a covalent bond with the cytochrome P450 enzyme and irreversibly inhibits it
D. The compound increases the activity of the cytochrome P450 enzyme by stabilizing its conformation
Question 13
In a diploid cell, what is the ratio of the number of alleles for a particular gene to the total number of alleles in the cell?
A. 1:1
B. 2:1
C. 1:2
D. 2:2
Question 14
A solution of 0.1 M NaCl is prepared by dissolving 5.84 g of NaCl in 1 L of water. What is the concentration of Na+ ions in the solution?
A. 0.01 M
B. 0.1 M
C. 0.05 M
D. 0.005 M
Question 15
A 25-year-old woman presents with primary amenorrhea. Her karyotype is 46,XX. What is the most likely cause of her condition?
A. Turner syndrome
B. Androgen insensitivity syndrome
C. Mayer-Roki\tansky-Küster-Hauser syndrome
D. Swyer syndrome

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