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Transport of oxygen gas.
The alveoli have a higher concentration of oxygen gas; than the blood in pulmonary capillaries; oxygen diffuses across alveoli wall, endothelium of capillaries; into red blood cells; where
it combines with haemoglobin; to form oxyhaemoglobin; a compound that dissociates easily;
it is then transported in this form to respiring tissues; in the capillaries of respiring tissues oxyhaemoglobin dissociates into oxygen and haemoglobin; Oxygen diffuse into tissue cells; along a concentration gradient.
Transport of carbon (IV) oxide.
High concentration of carbon (IV) oxide in the cells stimulates dissociation of oxyhaemoglobin in blood capillaries of the tissues; carbon (IV) oxide diffuses out of the cells tissue fluid, across the endothelium of tissue capillaries; into the red blood cells; where it combines with water to form a weak carbonic acid; which dissociates into hydrogen carbonate and hydrogen ions; hydrogen ions combine with haemoglobin to form haemoglobinic acid; thus pH of the red blood cells and plasma remains constant; the hydrogencarbonate ions diffuse into the plasma and are transported in this form to lungs; a little of carbon (IV) oxide is transported in the plasma in form of hydrogencarbonate ions to the lungs; in the pulmonary capillaries, carbon (IV) oxide is released from the hydrogencarbonate ions and diffuses into the alveoli along a concentration gradient ; the enzyme carbonic anhydrase in red blood cells speed up loading and off-loading of carbon(IV) oxide;
sharon kalunda answered the question on May 27, 2019 at 13:00
- Name the process in the human body that ensures that haemolysis of red blood cells is prevented.(Solved)
Name the process in the human body that ensures that haemolysis of red blood cells is prevented.
Date posted: May 27, 2019. Answers (1)
- What term is used to describe the solution with equal solute concentration as that of the cells?(Solved)
What term is used to describe the solution with equal solute concentration as that of the cells?
Date posted: May 27, 2019. Answers (1)
- An experiment was carried out in which red blood cells were put in salt solutions of different concentrations. The table below shows the percentage of...(Solved)
An experiment was carried out in which red blood cells were put in salt solutions of different concentrations. The table below shows the percentage of cells which were destroyed by haemolysis in different salt concentration.
(a) Draw a graph of percentage of red blood cells haemolysed against salt concentration.
(b) Explain haemolysis of red blood cells.
(c) From the graph, state:
(i) the salt concentration at which 50% red blood cells were haemolysed.
(ii) the highest salt concentration when the largest number of red blood cells were haemolysed.
(d) (i) Suggest the normal salt concentration in the blood of the mammal from which the red blood cells were obtained.
(ii) Give a reason for your answer in (d) (i) above.
Date posted: May 27, 2019. Answers (1)
- A pea plant with smooth seeds was crossed with one with wrinkled seeds. The gene for smooth seeds is dorminant over that for wrinkled seeds....(Solved)
A pea plant with smooth seeds was crossed with one with wrinkled seeds. The gene for smooth seeds is dorminant over that for wrinkled seeds. Use letter R to represent the dorminant.
(a) State the genotype of the parents if the plant with smooth seeds was heterozygous.
(b) State the gametes produced by the smooth seeds and wrinkled seeds parents.
(c) State the genotype and phenotype of F1 generation. Show your working.
Date posted: May 27, 2019. Answers (1)
- The table below shows the number of Leopards and Impala in a grassland park over a period of six years.
(a) (i) What is the average...(Solved)
The table below shows the number of Leopards and Impala in a grassland park over a period of six years.
(a) (i) What is the average number of Impala in the park during the six years.
(ii) Account for the decrease in the number of leopards between the 4th and 6th year?
(b) Identify the trophic level occupied by
(i) Leopards
(ii) Tick feeding on the leopard.
(c) The two pyramids shown were obtained in the park.
Identify each type of pyramid.
Date posted: May 27, 2019. Answers (1)
- Study the diagram shown below of the anterior view of a lumbar vertebra of a mammal.
(a) Name the parts labelled: A,B,C
(b) State the function...(Solved)
Study the diagram shown below of the anterior view of a lumbar vertebra of a mammal.
(a) Name the parts labelled: A,B,C
(b) State the function of the part labelled D.
(c) State three roles of skeletons in organisms.
(d) State how the part labelled D in adapted for the function stated in (b) above.
Date posted: May 27, 2019. Answers (1)
- The graph below shows rates of photosynthesis in a plant at different temperatures.
(a) Account for the decrease in the rate of product formation at 410C...(Solved)
The graph below shows rates of photosynthesis in a plant at different temperatures.
(a) Account for the decrease in the rate of product formation at 410C from 5 to 20 minutes.
(b) Explain the results obtained at
(i) 250C.
(ii) 360C.
(c) (i) Other than temperature, state one external factor that affect the rate of photosynthesis.
(ii) Suggest the product which could have been used in the experiment.
Date posted: May 27, 2019. Answers (1)
- The diagram below shows a model of the nephron of a mammalian kidney.
(a) Which parts of the nephron are represented by the:
(i) Syringe?
(ii) Perforated rubber...(Solved)
The diagram below shows a model of the nephron of a mammalian kidney.
(a) Which parts of the nephron are represented by the:
(i) Syringe?
(ii) Perforated rubber tubing?
(iii) Free rubber tubing?
(b) Name the type of filtration taking place within the perforated rubber tubing.
(c) What would happen to the contents of the syringe if its handle was slowly pushed forward? Explain.
Date posted: May 27, 2019. Answers (1)
- Use the photographs provided to answer the questions that follow:
a) (i) Identify the type of cell division represented in the photographs A and B.
(ii)...(Solved)
Use the photographs provided to answer the questions that follow:
a) (i) Identify the type of cell division represented in the photographs A and B.
(ii) With a reason, name the stage of cell division represented in each case.
(iii) Name the parts of human body where the process B represented above occur.
b) (i) What type of fruit is represented by photograph I? Give two reasons.
(ii) Name the agent of dispersal for fruits II and III.
(iii) How are the fruits adapted for the mode of dispersal stated in (b) ( ii) above?
(iv) Identify the type of placentation shown by photograph I.
Date posted: May 27, 2019. Answers (1)
- Below are pictures from two different organisms.
(i) What is the specific function of the two structures shown in the pictures?
(ii) What type of structures...(Solved)
Below are pictures from two different organisms.
(i) What is the specific function of the two structures shown in the pictures?
(ii) What type of structures is represented by the two structures shown on the pictures?
Date posted: May 27, 2019. Answers (1)
- The picture below shows series of beaks in birds.
a) State the type of evolution that may have led to the emergence of the different beaks...(Solved)
The picture below shows series of beaks in birds.
a) State the type of evolution that may have led to the emergence of the different beaks shown on the pictures above.
(b) Name the type of evolution structure represented by the beaks shown on the pictures above.
(c) Observe the pictures carefully. From your observations, what features are responsible for the different types of beaks?
(d) Suggest the type of food likely eaten by birds whose beaks are shown in pictures A, B, C and D.
(e) Briefly state how beak shown in picture A is adapted to feeding.
Date posted: May 27, 2019. Answers (1)
- The photographs below represent different types of animals. Study them carefully and answer the questions that follow.
(a) State two observable differences between K and M....(Solved)
The photographs below represent different types of animals. Study them carefully and answer the questions that follow.
(a) State two observable differences between K and M.
(b) Classify specimen M into the following taxa giving reasons for each case.
(i) Phylum
Reasons
(ii) Class
(iii) Reasons
(c) Name the type of skeleton found in the specimen O.
(d) (i) Name the class to which the specimen N belongs.
(ii) Give three reasons for your answer in (d) (i) above.
Date posted: May 27, 2019. Answers (1)
- You have been provided with photographs of specimens labelled Q1, Q2 and Q3. Examine them.
a) By using observable features only, state the phylum and class...(Solved)
You have been provided with photographs of specimens labelled Q1, Q2 and Q3. Examine them.
a) By using observable features only, state the phylum and class to which the specimens belong. By using the three specimens, give reasons for each case.
(a) Phylum
Reasons
(b) Class
Reasons
(c) Using observable features only, give three differences between specimen Q1 and Q3.
(d) (i) Apart from locomotion, state the other role of the hind limbs of specimen Q1.
(ii) How are the hind limbs of specimen Q1 adapted to perform role named in d (i) above.
Date posted: May 27, 2019. Answers (1)
- Study the photographs below and answer the questions below.
(i) To which phylum does organisms x,y and z belong to.
(ii) Name the classes to which...(Solved)
Study the photographs below and answer the questions below.
(i) To which phylum does organisms x,y and z belong to.
(ii) Name the classes to which X, Y and Z belongs to.
(iii) Give two important economic roles of specimen Y.
(iv) Give three harmful effects of specimen X to animals.
(v) With reasons identify two modes of locomotion of specimen Y .
Date posted: May 27, 2019. Answers (1)
- Study the photographs below and answer the questions below.
a) Name the sub-division of the plant from which the photo was taken.
b) Using observable features...(Solved)
Study the photographs below and answer the questions below.
a) Name the sub-division of the plant from which the photo was taken.
b) Using observable features on the photograph give reasons for your answer in (a) above.
c) Name the agent of pollination for the flower in the photograph
d) State three observations on the photograph that supports your answer in (c) above.
e) Name the class of the plant from which the photo was taken.
f) Using observable features on the photograph, give three reasons for your answer in (e) above.
g) Give two adaptations of the part labeled B to its pollination function.
Date posted: May 27, 2019. Answers (1)
- The photographs in Plate J, K and L shows the anterior part of two different animals,
Plate L shows the longitudinal dissection of Plate K. Examine...(Solved)
The photographs in Plate J, K and L shows the anterior part of two different animals,
Plate L shows the longitudinal dissection of Plate K. Examine the photographs and answer the questions below.
(a) (i) State the class to which the animal organ in Plate J belongs.
(ii) State the habitat of the animal.
(iii) Give a reason for your answer in (ii) above.
(b) (i) Name the organ shown in the photograph in Plate J.
(ii) State the function of the organ named above (i).
(iii) Name the structure that protects the organ named in (b(i) above from mechanical damage .
(iv) From observable features only explain three adaptation of the organ to its function.
(c) (i) Identify the structure in the photograph Plate K and L.
(ii) Give a reason for your answer.
(iii) Using observable features only state three adaptations of the structure to its functions.
Date posted: May 27, 2019. Answers (1)
- Study the photographs and answer the following questions.
I) The photograph in Plate 5 shows the germination process in a species of legume.
(a) (i) Name the...(Solved)
Study the photographs and answer the following questions.
I) The photograph in Plate 5 shows the germination process in a species of legume.
(a) (i) Name the type of germination shown in the photograph.
(ii) Give a reason for your answer.
(b) Other than germination the seedling have shown some responses.
(i) Name two responses shown in the photograph.
(ii) State one survival value of each of the response named above.
(II) Examine the photograph in Plate 6 and Plate 7 which show different essential parts of a flower of a species on two different plants.
(a) Name the flower parts shown in Plate 6 and Plate 7.
(b) (i) Name the phenomenon described in the statement above.
(ii) Explain the significance of the phenomena stated in (a)(i) above.
(c) (i) State the mode of pollination of the flower shown in the photograph.
(ii) Give a reason for your answer.
(d) (i) State the type of pollination of the flower shown in the photograph.
(ii) Give two reasons for your answer.
Date posted: May 27, 2019. Answers (1)
- Below are drawing of various organisms. Examine them.
i ) Name the phylum to which B belongs.
ii) Give three reasons for your answer in (a) (i)...(Solved)
Below are drawing of various organisms. Examine them.
i ) Name the phylum to which B belongs.
ii) Give three reasons for your answer in (a) (i) above.
b) Name the class to which specimen A belongs.
c) Give three differences between specimen B and E.
d)Use the dichotomous key provided to identify the organism.
a) Jointed legs present............................................................................ go to 2
b) Jointed legs absent.............................................................................. go to 7
a) Have 3 pairs of legs............................................................................ go to 3
b) Have more than 3 pairs of legs........................................................... go to 5
a) With wings.......................................................................................... go to 4
b) Without wings.................................................................................... Anoplura
a) Have one pair of wings....................................................................... Diptera
b) Have two pairs of wings..................................................................... Hymenoptera
a) Have four pairs of legs........................................................................ Arachnida
b) Have more than 10 pairs of legs.......................................................... go to 6
a) With one pair of legs per segment...................................................... Chilopoda
b) With two pairs of legs per body segment........................................... Diplopoda
a) With body enclosed in a shell............................................................. Mollusca
b) Body surface with spiny projections................................................... Echinodermata.
Identify steps followed to identify organism A, B, C, and E
Date posted: May 27, 2019. Answers (1)
- i)Identify the type of ovary shown in the photographs below.
ii) Name the parts labeled K and L
iii)Identify the type of section shown in the...(Solved)
i)Identify the type of ovary shown in the photographs below.
ii) Name the parts labeled K and L
iii)Identify the type of section shown in the photographs X and Y above.
Date posted: May 27, 2019. Answers (1)
- The photographs below show different plants.
a) Name the class of the plants from which the photographs were taken.
b) Name the agent of pollination for the...(Solved)
The photographs below show different plants.
a) Name the class of the plants from which the photographs were taken.
b) Name the agent of pollination for the flowers in the photographs above.
c) State one observation on the photographs that support your answer in (b) above.
Date posted: May 27, 2019. Answers (1)