K.C.S.E Biology Q & A - MODEL 2018PP1QN15
Explain why a bony fish dies shortly after being removed from water.
answers
K.C.S.E Biology Q & A - MODEL 2017PP1QN19
The table below shows the percentage concentration of certain substances in blood plasma, glomerular filtrate and urine in a human being at a particular time.
​(a) Explain the likely impact on the composition of urine in case of the following:
(i) Vigorous physical exercises (ii) a meal rich in proteins (b) Name the processes responsible for: (i) Presence of glucose in the glomerular filtrate (ii) absence of glucose in urine
answers
​a. i) Less water and urea; since sorne is excreted/eliminated through the skin (as sweat);
ii) increased amount of urea in the urine; due to deamination of amino acids (from proteins); b. i) ultra filtration; ii) Selective reabsorption;
K.C.S.E Biology Q & A - MODEL 2016PP2QN08
Describe how the mammalian heart is structurally adapted to its function.
answers
K.C.S.E Biology Q & A - MODEL 2016PP1QN27
Name the opening to the chamber of the heart of an insect.
answer
K.C.S.E Biology Q & A - MODEL 2016PP1QN27
Name an organism which has a single circulatory system.
answer
K.C.S.E Biology Q & A - MODEL 2016PP1QN27
What is single circulatory system?
answer
K.C.S.E Biology Q & A - MODEL 2016PP1QN04
State three functions of blood other than transport.
answers
K.C.S.E Biology Q & A - MODEL 2016PP1QN04
Name one defect of the circulatory system in humans.
answers
K.C.S.E Biology Q & A - MODEL 2016PP1QN01
State two ways in which the muscles of the mammalian heart are special.
ANSWERS
K.C.S.E Biology Q & A - MODEL 2015PP2QN08
How is a mammalian heart structurally adapted to its function?
ANSWERS
K.C.S.E Biology Q & A - MODEL 2015PP1QN03
.An individual is of blood group B positive.
(a) Name the antigens in the individual’s blood. (b) Give the reason why the individual cannot receive blood from a blood group A donor.
answers
​(a) (Antigen) B; Rhesus (antigen)/Rhesus factor/Antigen D
(b) Has antibody a in the blood plasma of the recipient and will correspond with antigen A in the donor’s blood, hence there will be antigen antibody reaction/agglutination. K.C.S.E Biology Q & A - MODEL 2014PP2QN02
The diagram below illustrates the role played by red blood cells in the transportation of carbon (1V) oxide.
​(a) Other than the carbon (IV) oxide transportation in the red blood cells, name the other form of carbon (1V) oxide transportation in humans.
(b) (i) Name substance F (ii) Name the enzyme marked C and state its role in the reaction. Enzyme Role (c) Explain why transportation of carbon (1V) oxide in red blood cells is advantageous. (d) Explain the role of calcium ions in blood clotting.
ANSWERS
​(a) Carbonic acid/carbaminohaemoglobin/hydrogen carbonate;
(b) (i) Water; (ii) Carbonic acid; Role: catalyses reaction between carbon IV oxide and water to form (weak) carbonic acid; (c) Prevents accumulation of acidity/maintains pH of blood since hydrogen ions combine with haemoglobin to form Haemoglobin acids; Faster; due to the catalytic effect of carbonic anhydrase; (d) Activates thromboplastin; thrombokinase to neutralize heparin/convert prothrombin to thrombin; K.C.S.E Biology Q & A - MODEL 2014PP1QN24
The table provided shows the transportation of substances in the human body.
​Name the substances represented by
M N P
ANSWERS
​M - lungs;
N - Urea, ammonia. ; P - Digested food. water; mineral ions;
K.C.S.E Biology Q & A - MODEL 2013PP2QN07
Describe the process of blood clotting in human beings.
ANSWERS
When a blood vessel is cut/injured platelets/thrombocytes/damaged tissue/wound is exposed to the air: they release thrombokinase/thromboplastin ; an enzyme that activates the conversion of prothrombin: to thrombin: in the presence of calcium ions: vitamin K/ phylloquinone ; is needed for the formation of prothrombin; Thrombin converts (soluble blood protein) fibrinogen ; into (the fibrous form) fibrin; which forms a mesh / network across the wound: The clot so formed prevents excessive bleeding: and entry of disease agents/pathogens/micro-organisms/microbes;
K.C.S.E Biology Q & A - MODEL 2013PP1QN24
Explain three protective functions of mammalian blood.
answers
|
TOPICSFORM 1
Form 2
Form 3
Form 4
Archives
December 2024
Categories
All
|