Exam Body:
Which of the following food substances is digested in the stomach?
A) Carbohydrate
B) Fats and oil
C) Fats and proteins
D) Proteins
E) Carbohydrates and fats
Exam Body: JAMB
Protein digestion occurs in the stomach and duodenum in which 3 main enzymes, pepsin secreted by the stomach, trypsin and chymotrypsin secreted by the pancreas, break down food proteins into polypeptides that are then broken down by various exopeptidases and dipeptidases into amino acids.
Carbohydrate digestion begins in the mouth with the mechanical action of chewing and the chemical action of salivary amylase. Carbohydrates are not chemically broken down in the stomach, but rather in the small intestine.
Lipids, or fat on the other hand, go undigested in your digestive tract until they reach your small intestine, where they meet bile. Bile contains bile salts, which act as an emulsifier of lipids. This breaks the large fat droplets into smaller droplets that are then easier for the fat-digesting enzyme pancreatic lipase to digest.
Explanation provided by Nigerian Scholars
The conversion of excess amino acids into urea occurs in the
A) Kidney
B) pancreas
C) villi
D) liver
E) spleen
Exam Body: JAMB
The conversion of excess amino acids into urea occurs in the liver.
In the human body, deamination takes place primarily in the liver. In situations of excess protein intake, deamination is used to break down amino acids for energy. The amino group is removed from the amino acid and converted to urea.
Explanation provided by Nigerian Scholars
For pollination and fruit formation, the essential part(s) of the flower should be the
A) corolla
B) ovary
C) pistil (gynoecium)
D) ovules
E) receptacle
Exam Body: JAMB
For pollination and fruit formation, the essential part(s) of the flower should be the pistil or gynoecium.
Pollination occurs in the stigma of a flower, which is the female reproductive part of the flower. After pollination, the seeds grow in the base of the pistil, which is called the ovule.
Explanation provided by Nigerian Scholars
Which one of the following parts of the mammalian body is most closely associated with the production of urine?
A) Malpighian capsule
B) Urinary bladder
C) Ureter
D) Vas deferens
E) Urethra
Exam Body: JAMB
The Malpighian or Bowman's capsule is a cup-like sack at the beginning of the tubular component of a nephron in the mammalian kidney that performs the first step in the filtration of blood to form urine.
Explanation provided by Nigerian Scholars
A potometer is used to determine the rate at which a shoot
A) respires
B) sucks air bubbles
C) loses weight
D) absorbs water
E) transpires
Exam Body: JAMB
A potometer is a device used for measuring the rate of water uptake of a leafy plant shoot. The main reason for water uptake by a cut shoot is transpiration (evaporation in plants) and is effected by the transpiration stream.
Explanation provided by Nigerian Scholars
A green plant growing in a compost pit is feeding
A) holozoically
B) parasitically
C) saprophytically
D) holophytically
E) in none of the above ways
Exam Body: JAMB
In holophytic nutrition, an organism produces its own food through photosynthesis which is the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water.
Holozoic nutrition is a method of nutrition used by animals that involves the ingestion of liquid or solid organic material, digestion, absorption and assimilation of it to utilize it.
Explanation provided by Nigerian Scholars
The part of the cell solely responsible for respiration is the
A) nucleus
B) nucleolus
C) mitochondria
D) golgi apparatus
E) endoplasmic reticulum
Exam Body: JAMB
The most prominent roles of mitochondria are to produce the energy currency of the cell, ATP (adenosine triphosphate), through respiration, and to regulate cellular metabolism.
Explanation provided by Nigerian Scholars
In anaerobic respiration, glucose is converted to one of the following
A) Carbon dioxide and water
B) Carbon dioxide only
C) Carbon dioxide and alcohol
D) Alcohol and water
E) water and acetic acid
Exam Body: JAMB
Anaerobic respiration is the process of producing cellular energy without oxygen. In anaerobic respiration, glucose is converted to carbon dioxide and alcohol.
Explanation provided by Nigerian Scholars
During excretion of urea there is also a corresponding re-absorption of water into the blood. This re-absorption takes place in the
A) uriniferous tubules
B) Bowman's capsule
C) glomerulus
D) malpighian capsule
E) renal artery
Exam Body: JAMB
The uriniferous tubule is the functional unit of the kidney, composed of a long convoluted portion (nephron) and an intrarenal collecting duct, through which renal filtrate from the renal corpuscle flows and is changed to urine by reabsorption and secretion.
Explanation provided by Nigerian Scholars
If the bark and phloem tissue of a woody shoot are peeled off by ringing, the whole plant will eventually die because
A) water does not reach the leaves
B) water and salts remained below the ring portion
C) there is a withdrawal of water from the root by soil
D) manufactured food does not reach the roots
E) the roots store too much water
Exam Body: JAMB
If the bark and phloem tissue of a woody shoot are peeled off by ringing, the whole plant will eventually die because manufactured food does not reach the roots.
Explanation provided by Nigerian Scholars
The filament of spirogyra were put into equal volumes of sugar solutions X and Y. After 5 minutes, filaments from solution X had their cells contents rounded up while those from Y were unaffected. The experiment shows that
A) solution X was stronger than Y
B) solution Y was stronger than X
C) Spirogyra used up the sugar in solution X
D) solution X is good for stimulating sexual reproduction in Spirogyra
E) solution Y was less contaminated than X
Exam Body: JAMB
Spirogyra is a filamentous green alga of a genus that includes blanket weed. The sugar solution X was stronger than Y because it caused the spirogyra filaments from solution X had their cells contents rounded up
Explanation provided by Nigerian Scholars
which part of the human brain is concerned with reflexes controlling the rate of heart beat and breathing?
A) Medulla
B) Cerebrum
C) Cerebellum
D) Pineal body
E) Olfactory lobe
Exam Body: JAMB
The medulla oblongata helps regulate breathing, heart and blood vessel function, digestion, sneezing, and swallowing. This part of the brain is a center for respiration and circulation. Sensory and motor neurons (nerve cells) from the forebrain and midbrain also travel through the medulla.
Explanation provided by Nigerian Scholars