2018 - WAEC Biology Past Questions and Answers - page 4
Which of the following instruments is used to determine the turbidity of water?
The secchi disc is used to check for the transparency and the turbidity of water.
In an ecosystem, the least efficient energy transfer link is from the
From the food chain, the energy flows from the producers to the primary consumer to the secondary consumers and about 90% of the energy is lost in the process of this transfer. Hence, the energy level by the time it gets to the secondary consumers, there is less energy transferred to the decomposers.
Xerophytes have the following characteristics aimed at conserving water except
The xerophytes have reduced leaf size in order to reduce the surface area, thereby reducing the water loss in the plant.
An association between living organisms in which one lives on and feeds at the expense of the other is known as
A parasite is an organism that lives on or in a host organism and gets its food from or at the expense of its host.
When large numbers of organisms share limited space and resources, the immediate result is
Competition in a territory is as a result of a hassle for the available resources within the territory. For instance, when the water in a river seems to be drying out, the organisms in the water begin to compete for the water.
Which of the following disease ic caused by a bacterium?
Syphilis is caused by a bacterium known as Trepenoma pallidum. It is majorly passed on by sex.
Conservation of wildlife is necessary mainly because
Wildlife conservation is necessary for the prevention of the extinction of wildlife. It helps with the preservation of these wild animals.
Two unconscious patients X and Y whose blood group genotypes are AO and AB respectively were transfused with the blood from the same donor . Patient X immediately showed signs of difficulty in breathing while patient Y showed no negative reaction.
Patients X and Y were likely transferred with blood of genotype
The blood types A and AB can receive blood from blood types A and O but not B. Hence, if there was a problem after transfusion, it was most likely to be from BO.
Two unconscious patients X and Y whose blood group genotypes are AO and AB respectively were transfused with the blood from the same donor . Patient X immediately showed signs of difficulty in breathing while patient Y showed no negative reaction.
What should the hospital have done to prevent X from showing the symptom described above? Patient X should have
The basic technique in identification of the antigens and antibodies of blood groups is the agglutination test and can be done to prevent the clumping of the red blood cell. The symptom is due to clumping due to incompatible blood transfusion.
The greatest contribution to genetic studies was made by
Gregor Mendel is considered as the founder of modern science of genetics.