2020 WAEC GCE 1ST SERIES BIOLOGY OBJ & THEORY QUESTIONS AND ANSWERS

(1a) In Tabular Form 

– Hormonal –

(i)Transmission is chemical   

(ii)Slow transmission 

(iii)Response is wide spread

(iv) Target organs receive response

(v)Long lasting response

– Nervous-

(i)Transmission is electrical and chemical

(ii)Rapid transmission

(iii)Response localized

(iv) Effector organs receive response

(v)Short-lived response

(1bi)

(i) It increases oestradiol production. 

(ii) Essential in pubertal development.

 (1biii)

{pick any 3}

(i) it stimulates the liver to convert glycogen to Sugar thereby increasing the blood sugar level. 

(ii) it increases the rate of Heartbeat and breathing. 

(iii) it increases the muscle tone for higher work rate. 

(iv) it prepares the body for emergency. 

(v) it is associated with fear or anxiety and brings about shivering when the animal feels cold.

=============================================================

(3a)

(i) The roots of aquatic plants are shallow and spread out over a large area and serve as support

(ii) Aquatic plants have mechanism for maintaining a high osmotic concentration in their cell which is close to that of the water in their habitat

(iii) The roots of mangrove plants have many devices for taking in atmospheric oxygen

(iv) The seeds of mangrove plant germinates while they are still on the parent tree

(3bi)

Secondary succession is one of the two types ecological succession of a plants life. As opposed to the first, primary succession, secondary succession is a process started by an event that reduces an.

(3bii)

(i)temperatures

(ii)water

(iii)nutrient availability

(3biii)

Once a pond is created, seeds are flown in by birds or deposited by mammals who visit the pond. These first seed plants are called pond pioneers.As established plants grow and die they sink to the bottom of the pond and helping to fill in the shallow water. In other words Eventually the pond’s emergent plants may cover the entire pond turning the pond into a soggy marsh. In time the soft, wet ground of the marsh will be overtaken by plants and dry out. When that happens it means the pond has succeeded into a field or meadow. As plant life & soil conditions change, the wildlife attracted to the area will change.

(3c) 

(i) Sickle cell anemia

(ii) Color-blindness

(iii) Diabetes 

(iv) cystic fibrosis

=============================================================

(5a)

(i)supply of blood

(ii)macrophages

(iii)dendritic cells

(iv)lymph vessels

(v)nerve endings

(5b)

(i)Decay is the process of breaking down complex organic matter into simple substances by microorganisms.

This process allows the recycling of organic substances

(ii)Digestion is the method of breaking down complex organic matter into simple compounds by enzymes, to be absorbed by the body. This is usually converted into energy.

(5c)

(i)The different ways that animals and plants are interdependent in an ecosystem because they depend on each other for basic survival needs like food

(ii)For Protection 

(iii)For shelter and propagation. 

(iv)plants also benefit from animals in that animal can aid in seed dispersal ensuring the survival of plants in other regions of an ecosystem.

(5di)

(i)Density-dependent regulation can be affected by factors that affect birth Rates. 

(ii)And Affect death rates such as competition and predation

(5dii)

(i)Density-independent regulation can be affected by factors that affect birth and death rates such as abiotic factors

(ii)environmental factors, i.e. severe weather and conditions such as fire.

Posted by admin on 31st January 2020.

Categories: Waec Gce