Explain how an end-product inhibition in an enzyme controlled reaction is a negative feedback

01/31/2022 0

In  an enzyme controlled reaction which occurs in series, high concentration of final product acts as an allosteric inhibitor of the enzyme controlling the first ... Read More

Explain how Independent assortment of chromosomes during meiosis causes variation in sexually reproducing organisms.

01/31/2022 0

The orientation of bivalents at the equator of the spindle during metaphase I and orientation of chromosomes at equator in metaphase II are random. Chromosomes ... Read More

Explain how crossing over during meiosis causes variation in sexually reproducing organisms.

01/31/2022 0

During prophase I of meiosis, equivalent portions of homologous chromosomes are exchanged. In this way linked genes are separate and gametes with new gene combination ... Read More

During vaccination against tuberculosis (T.B), children are injected with a weakened strain of T.B bacteria. Explain how this procedure can result in long term defence against T.B.

01/31/2022 0

Weakened strains of T.B induce B-lymphocytes to divide rapidly by mitosis forming a clone of B-cells. Some of the B-cells differentiate into memory cells which ... Read More

Explain the function of antigens and antibodies in the immune system

01/31/2022 0

Antigens stimulate production of antibodies   antibodies bind with antigens rendering them harmless Read More

Explain how chlorosis affects primary productivity in plants.

01/31/2022 0

Chlorophyll content reduces, this reduces the amount of light absorbed for photosynthesis. The rate of photosynthesis decreases and hence primary productivity decrease. Read More

Explain how Water stress affects primary productivity in plants.

01/31/2022 0

Stomatal closure occurs in order to reduce water loss. Carbon dioxide is cut off reducing the rate of photosynthesis and primary productivity decrease Read More

What is meant by primary productivity?

01/31/2022 0

It is the rate at which primary producer produce organic matter per unit area per unit time Read More

Explain why diving mammals have reduced heart beat rate

01/31/2022 0

Diving mammals experience oxygen deprivation, heart beat rate is low to prolong the use of oxygen available Read More

Describe the physiological adaptations of plants to water shortage

01/30/2022 0

Describe the physiological adaptations of plants to water shortage Reversing stomatal rhythm i.e. open stomata open at night and close during the day to reduce ... Read More

Describe the physiological adaptations of vertebrates in dry environments, giving examples in each case 

01/30/2022 0

Describe the physiological adaptations of vertebrates in dry environments, giving examples in each case Evaporation of water from lungs is reduced by exhaling air at ... Read More

Explain the reproductive strategies of flowering plants that have led to their survival

01/30/2022 0

cross pollination leads to variations which promote survival mechanisms of dispersal of fruits and seeds enable colonization of new places and reduce intraspecific completion ovary ... Read More

Explain the reproductive strategies of flowering plants that have led to their diversity

01/30/2022 0

Explain the reproductive strategies of flowering plants that have led to their diversity / (promote out breeding) Dichogamy: anthers mature and stigma become receptive at ... Read More

How does instinctive behaviour differ from learned behaviour?

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How does instinctive behaviour differ from learned behaviour? Differenced between instinctive and learned behaviours   Instinctive behaviours Learned behaviours Inborn/inherited Acquired during life time Permanent/fixed/stereotyped ... Read More

Explain the benefits of social behaviour to social animal. 

01/30/2022 0

Species in large groups suffer less predators even when the predator is successful; The chance that one is picked is very low. Predators are more ... Read More

Explain how the body reacts when there is presence of antigens in the body

01/30/2022 0

Presence of antigens in the body stimulates the lymphocytes to produce corresponding antibodies; the antibodies attack the antigen in the following ways Clumps antigen and ... Read More

Explain how the body reacts when a blood vessel is cut

01/30/2022 0

Damage to a blood vessel causes platelets to stick together at the site of damage and produce clotting substances/thromboplastin. Thromboplastin stimulates conversion of plasma protein ... Read More

What are the likely consequences of over bleeding to an individual?

01/30/2022 0

  What are the likely consequences of over bleeding to an individual? It leads to reduction of blood pressure which slows blood flow It leads ... Read More

Give situations where the law of Independent Assortment may not apply

01/30/2022 0

Mutation Lethal gene Linked genes Epistasis or interaction of genes Thank you Read More

Why do bony fish actively take up salts through the gills during osmoregulation?

01/29/2022 0

Bony fish are fresh water fresh water organisms whose internal environment is hypertonic c and the surrounding water has little salts. Salts are actively taken ... Read More

Why the rate of breathing increases during exercise?

01/29/2022 0

The rate of breathing increases to provide oxygen for increased rate of respiration up to a maximum when the rate of breathing meets the demand ... Read More