Biology Past Questions And Answers
The phospholipid bilayer is critically important to the separation of the internal and external environment of the cell. What drives the formation of the phospholipid bilayer?
- A. None of these
- B. The external environment pushes non-polar hydrophobic fatty acid tails to form the inner layer and the polar hydrophobic head groups to form the outer layer.
- C. The external environment pushes non-polar hydrophilic fatty acid tails to form the inner layer and the polar hydrophobic head groups to form the outer layer.
- D. The external environment pushes non-polar hydrophobic fatty acid tails to form the inner layer and the polar hydrophilic head groups to form the outer layer.
The main function of the caudal fin in Tilapia is to
- A. propel it forward in water
- B. steer it while changing direction
- C. balance it in water
- D. enable it to float in water
Plants adapted for life in salty marsh are called
- A. hydrophytes
- B. xerophytes
- C. halophytes
- D. epiphytes
Sea water taken in by a living organism can be recycled into the atmosphere through all the following processes except
- A. transpiration
- B. digestion
- C. excretion
- D. respiration
Osmic acid boiled with a solution of food substance gave a black precipitate. This indicates the presence of
- A. fats and oil
- B. proteins
- C. amino acids
- D. starch
(a) Write short notes on each of the following:
(i) ecological niche
(ii) population density
(iii) climax continually
(b) Describe briefly the interactions between abiotic and biotic components of an ecosystem.
View Discussion (0)WAEC 2010 THEORYa. Classify the following biological associations under the headings in the table below:
(i) Remora and shark;
(ii) Lichen;
(iii) Cattle and white Egret;
(iv) Tapeworm in the gut of humans;
(v) Flowers and Honeybees;
(vi) Mistletoe and Cacao plant.
| Parasitism | Mutualism | Commensalism |
[6 marks]
b. (i) Statethreeadaptive features of parasites. [6 marks]
(ii) Statetwoeffects of parasites on their hosts. [2 marks]
c. (i) What are saprophytes? [2 marks]
(ii) Givefourexamples of saprophytes. [4 marks]
View Discussion (0)WAEC 2019 THEORYCarbon (IV) oxide content of the atmosphere is least affected by
- A. cutting down and clearing of forests
- B. forest fires
- C. burning of fossil fuels
- D. plant and animal respiration
Which of the following substances has the highest amount of energy in joules per unit weight?
- A. Carbohydrates
- B. Fats
- C. Proteins
- D. Vitamins
Paternity disputes can most accurately be resolved through the use of
- A. blood group typing
- B. finger printing
- C. tongue rolling
- D. DNA Analysis