How well do you understand living things and their vital processes? Whether you are preparing for JAMB, WAEC, NECO and Post-UTME, these Biology past questions and answers cover such subjects as the chemistry of life, botany, evolution, genetics, ecology etc to help you know what to expect, improve your speed and confidence and be really prepared for the actual aptitude test.
Which of the following is TRUE of the process of conjugation in Paramecium?
Micronucleus disintegrates
Each ex-conjugant divides only once
Macro nucleus undergoes division
Each micronucleus divides twice
Correct answer is D
In Paramecium, Conjugation is a form of sexual reproduction. It is a temporary union of two individuals of same species for mutual exchange of genetic materials.
Through a process called conjugation, two paramecia line up side by side and then fuse together.
The two paramecium separate and go on their way in their watery environment.
They begin again to produce multiple copies of themselves through asexual fission.
During sexual reproduction, the micronuclei of each paramecium undergo meiosis, ultimately halving the genetic content to create a haploid nucleus.
These are exchanged between the two connected mates.
The haploid nuclei from each mate fuse to create a new, genetically varied, micronucleus.
The blood vessel which carries blood from the alimentary canal to the liver is the
hepatic artery
hepatic vein
hepatic portal vein
mesenteric artery
Correct answer is C
The portal vein or hepatic portal vein (HPV) is a blood vessel that carries blood from the gastrointestinal tract, gall bladder, pancreas, and spleen to the liver.
This blood contains nutrients and toxins extracted from digested contents.
Glucose
Starch
Egg White
Maltose
Correct answer is A
In the lab, we used Benedict's reagent to test for one particular reducing sugar: glucose.
Benedict's reagent starts out aqua-blue. As it is heated in the presence of reducing sugars, it turns yellow to orange.
The villus in the small intestine is significant because it
increases the surface area for absorption
increases the surface area for digestion
assists in mixing digested food
assists in filtering undigested food
Correct answer is A
The villi of the small intestine project into the intestinal cavity, greatly increasing the surface area for food absorption and adding digestive secretions.
Aged erythrocytes are destroyed in the
pancreas
liver
lymph nodes
kidney
Correct answer is B
Together with the spleen, the liver breaks down worn out red blood cells (erythrocytes).