Q. 1
Biology & Medical Sciences
Difficulty: MEDIUM
(1 Mark)
Which class of immunoglobulins (antibodies) is the most abundant in human blood serum and can cross the placenta to confer passive immunity to the fetus?
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Step-by-Step Explanation & Concept Rationale
IgG constitutes ~75–80% of total serum antibodies and is the sole isotype transported across the human placental barrier.
Q. 2
Biology & Medical Sciences
Difficulty: MEDIUM
(1 Mark)
Which antibody class is predominantly found in mucosal secretions (saliva, tears, breast milk, gastrointestinal fluid)?
💡
Step-by-Step Explanation & Concept Rationale
IgA provides primary mucosal surface defense against bacterial and viral invasion.
Q. 3
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
What term describes a symbiotic ecological relationship where both participating species derive mutual benefit?
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Step-by-Step Explanation & Concept Rationale
Mutualism is an obligate or facultative interaction where both organisms experience fitness gains (+/+).
Q. 4
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
According to Lindeman's 10% Ecological Law, what percentage of energy is typically transferred from one trophic level to the next higher level in a food chain?
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Step-by-Step Explanation & Concept Rationale
Around 90% of energy is lost as metabolic heat and waste at each trophic step, transferring only ~10% to the next level.
Q. 5
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
Fluid mosaic model of plasma membrane was proposed in 1972 by:
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Step-by-Step Explanation & Concept Rationale
S.J. Singer and G.L. Nicolson proposed the fluid mosaic model describing membranes as a fluid phospholipid bilayer with embedded proteins.
Q. 6
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In cell biology & macromolecular biochemistry #10: Which amino acid is the starting codon (AUG) in eukaryotic protein synthesis?
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Step-by-Step Explanation & Concept Rationale
AUG codes for methionine in eukaryotes (and formylmethionine in prokaryotes), serving as the universal start codon.
Q. 7
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In cell biology & macromolecular biochemistry #15: Which amino acid is the starting codon (AUG) in eukaryotic protein synthesis?
💡
Step-by-Step Explanation & Concept Rationale
AUG codes for methionine in eukaryotes (and formylmethionine in prokaryotes), serving as the universal start codon.
Q. 8
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In cell biology & macromolecular biochemistry #20: Which amino acid is the starting codon (AUG) in eukaryotic protein synthesis?
💡
Step-by-Step Explanation & Concept Rationale
AUG codes for methionine in eukaryotes (and formylmethionine in prokaryotes), serving as the universal start codon.
Q. 9
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In cell biology & macromolecular biochemistry #25: Which amino acid is the starting codon (AUG) in eukaryotic protein synthesis?
💡
Step-by-Step Explanation & Concept Rationale
AUG codes for methionine in eukaryotes (and formylmethionine in prokaryotes), serving as the universal start codon.
Q. 10
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In cell biology & macromolecular biochemistry #30: Which amino acid is the starting codon (AUG) in eukaryotic protein synthesis?
💡
Step-by-Step Explanation & Concept Rationale
AUG codes for methionine in eukaryotes (and formylmethionine in prokaryotes), serving as the universal start codon.
Q. 11
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In cell biology & macromolecular biochemistry #35: Which amino acid is the starting codon (AUG) in eukaryotic protein synthesis?
💡
Step-by-Step Explanation & Concept Rationale
AUG codes for methionine in eukaryotes (and formylmethionine in prokaryotes), serving as the universal start codon.
Q. 12
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In cell biology & macromolecular biochemistry #40: Which amino acid is the starting codon (AUG) in eukaryotic protein synthesis?
💡
Step-by-Step Explanation & Concept Rationale
AUG codes for methionine in eukaryotes (and formylmethionine in prokaryotes), serving as the universal start codon.
Q. 13
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
The central dogma of molecular biology describes the directional flow of genetic information as:
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Step-by-Step Explanation & Concept Rationale
Formulated by Francis Crick: genetic code proceeds from DNA (replication/transcription) to RNA, and then translates into functional protein.
Q. 14
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In molecular genetics #10: What molecular technique is used to amplify minute quantities of specific DNA segments in vitro?
💡
Step-by-Step Explanation & Concept Rationale
PCR utilizes thermal cycling with Taq polymerase to exponentially amplify targeted DNA sequences.
Q. 15
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In molecular genetics #15: What molecular technique is used to amplify minute quantities of specific DNA segments in vitro?
💡
Step-by-Step Explanation & Concept Rationale
PCR utilizes thermal cycling with Taq polymerase to exponentially amplify targeted DNA sequences.
Q. 16
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In molecular genetics #20: What molecular technique is used to amplify minute quantities of specific DNA segments in vitro?
💡
Step-by-Step Explanation & Concept Rationale
PCR utilizes thermal cycling with Taq polymerase to exponentially amplify targeted DNA sequences.
Q. 17
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In molecular genetics #25: What molecular technique is used to amplify minute quantities of specific DNA segments in vitro?
💡
Step-by-Step Explanation & Concept Rationale
PCR utilizes thermal cycling with Taq polymerase to exponentially amplify targeted DNA sequences.
Q. 18
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In molecular genetics #30: What molecular technique is used to amplify minute quantities of specific DNA segments in vitro?
💡
Step-by-Step Explanation & Concept Rationale
PCR utilizes thermal cycling with Taq polymerase to exponentially amplify targeted DNA sequences.
Q. 19
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In molecular genetics #35: What molecular technique is used to amplify minute quantities of specific DNA segments in vitro?
💡
Step-by-Step Explanation & Concept Rationale
PCR utilizes thermal cycling with Taq polymerase to exponentially amplify targeted DNA sequences.
Q. 20
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In molecular genetics #40: What molecular technique is used to amplify minute quantities of specific DNA segments in vitro?
💡
Step-by-Step Explanation & Concept Rationale
PCR utilizes thermal cycling with Taq polymerase to exponentially amplify targeted DNA sequences.
Q. 21
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
The normal resting pacemaker of the human heart is the:
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Step-by-Step Explanation & Concept Rationale
The SA node in the right atrium initiates rhythmic electrical impulses causing atrial and ventricular systole at 60-100 bpm.
Q. 22
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In human organ physiology #10: What is the primary digestive enzyme in saliva that begins carbohydrate digestion by breaking starch into maltose?
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Step-by-Step Explanation & Concept Rationale
Salivary amylase hydrolyzes alpha-1,4 glycosidic bonds in starch to initiate carbohydrate digestion in the oral cavity.
Q. 23
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In human organ physiology #15: What is the primary digestive enzyme in saliva that begins carbohydrate digestion by breaking starch into maltose?
💡
Step-by-Step Explanation & Concept Rationale
Salivary amylase hydrolyzes alpha-1,4 glycosidic bonds in starch to initiate carbohydrate digestion in the oral cavity.
Q. 24
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In human organ physiology #20: What is the primary digestive enzyme in saliva that begins carbohydrate digestion by breaking starch into maltose?
💡
Step-by-Step Explanation & Concept Rationale
Salivary amylase hydrolyzes alpha-1,4 glycosidic bonds in starch to initiate carbohydrate digestion in the oral cavity.
Q. 25
Biology & Medical Sciences
Difficulty: EASY
(1 Mark)
In human organ physiology #25: What is the primary digestive enzyme in saliva that begins carbohydrate digestion by breaking starch into maltose?
💡
Step-by-Step Explanation & Concept Rationale
Salivary amylase hydrolyzes alpha-1,4 glycosidic bonds in starch to initiate carbohydrate digestion in the oral cavity.
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