a) A - concentration of salt was isotonic; to that of the cytoplasm of the red blood cells hence no change;
b) B - most cells haemolysed; due to hypotonic salt solution;
sharon kalunda answered the question on September 18, 2019 at 11:43
- The photograph below is two varieties of peppered moth Biston betularia resting on the bark of a tree.(Solved)
The photograph below is two varieties of peppered moth Biston betularia resting on the bark of a tree.
Explain using the photograph how natural selection will determine the survival of each variety.
Date posted: September 18, 2019. Answers (1)
- Study the flow diagram showing the role of the pancreas in controlling blood glucose concentration;(Solved)
Study the flow diagram showing the role of the pancreas in controlling blood glucose concentration;
i) Name the endocrine tissue labelled A.
ii) Name the hormone B produced by a cells.
iii) Name the hormone C produced by the B cells.
iv) Name the process represented by the dotted lines.
v) Briefly describe how hormone B brings about a rise in blood glucose concentration when it reaches
the liner.
Date posted: September 18, 2019. Answers (1)
- The photograph labeled K is an intact mammalian heart while photograph K1 and K2are sections of a mammalian heart .Examine them(Solved)
The photograph labeled K is an intact mammalian heart while photograph K1 and K2are sections of a mammalian heart .Examine them
The vessels labeled A and B drains blood in a chamber that leads to another chamber labeled J. The blood vessel labeled 3 drains blood into the chamber labeled L. When water is pumped under low pressure through vessel 3, it flows out through the vessel labeled 4. When water is pumped under low pressure through vessels A and B it flows out through the vessel labeled 2.
i. Name the chambers labeled Land J
ii. Name the blood vessels 2,3 and 4.
iii. Observe the walls of chamber J and those of chamber N in the sections of the heart. Account for the difference in the thickness of the walls.
iv. Name the structure labeled H and state its role.
Date posted: September 18, 2019. Answers (1)
- The photographs below show specimens of different types of fruits. Examine them.(Solved)
The photographs below show specimens of different types of fruits. Examine them.
a) State the differences between specimens P and R
b) State the types of gynoecium and placentation of specimens P,S and V.
Specimen P:Gynoecium
Placentation
Specimen S Gynoecium
Placentation.
Specimen V Gynoecium.
Placentation
Name the mode of dispersal for each specimen and the features that adapt the specimen its mode of dispersal.
Date posted: September 18, 2019. Answers (1)
- Students carried an experiment and arranged their apparatus as shown below, to investigate a certain phenomenon.The set up was placed in light.(Solved)
Students carried an experiment and arranged their apparatus as shown below, to investigate a certain phenomenon.The set up was placed in light.
a) State the likely aim of the set up
b) State the role of the syringe in the set-up above
c) (i) Name gas X.
(ii) Write an equation to show how gas X was formed in the set-up.
d) State three factors that increase the rate of enzyme activity.
(e) Give a reason why the test tube is immersed in a beaker of water.
Date posted: September 18, 2019. Answers (1)
- What is Ecdysis?(Solved)
What is Ecdysis?
Date posted: September 18, 2019. Answers (1)
- Examine the diagram shown below and answer questions that follow.(Solved)
Examine the diagram shown below and answer questions that follow.
(i) What does the diagram represent?
(ii) Name parts labeled.
A
B
E
Date posted: September 18, 2019. Answers (1)
- A person met a lion as he walked along a forest path.
(i) Name the hormone that was secreted in his bloodstream and state its source....(Solved)
A person met a lion as he walked along a forest path.
(i) Name the hormone that was secreted in his bloodstream and state its source.
(ii) What is the effect of the hormone in his:
(a) Circulatory system.
(b) Respiratory system.
Date posted: September 18, 2019. Answers (1)
- Where is the hormone thyroxin produced?(Solved)
Where is the hormone thyroxin produced?
Date posted: September 18, 2019. Answers (1)
- The following processes occur during stages of meiosis. Indicate the stage in which they occur.(Solved)
The following processes occur during stages of meiosis. Indicate the stage in which they occur.
(i) Pairing of chromosomes.
(ii) Centromere divides.
(iii) Bivalent at the equator.
Date posted: September 18, 2019. Answers (1)
- Cell V in the diagram below went through the 2nd meiotic division. The results were as in the gamete cells W and X.(Solved)
Cell V in the diagram below went through the 2nd meiotic division. The results were as in the gamete cells W and X.
i) Name the type of mutation demonstrated in the diagrams.
ii) Supposing gamete X fused with a normal gamete during fertilization, name a disorder in humans resulting from such a condition.
Date posted: September 18, 2019. Answers (1)
- The diagram below represents the process that brings about blood clotting.(Solved)
The diagram below represents the process that brings about blood clotting.
a) Name the substances A and B.
b) Name one source of calcium ions in the diet.
c) Name one more other role of calcium in the body.
d) Name the blood cells that are involved in blood clotting.
e) List down three structural adaptations of the red blood cells to their functions.
Date posted: September 18, 2019. Answers (1)
- Use the nitrogen cycle below to answer the questions that follow.(Solved)
Use the nitrogen cycle below to answer the questions that follow.
a) Name the processes represented by
i) G
ii) Y
iii) K
b) Name the group of organisms that cause processes
i) C
ii) J
iii) L
c) Name the state in which nitrogen exist in
i) Plant tissue
ii) Atmosphere
Date posted: September 18, 2019. Answers (1)
- Pea seedlings were treated as follows;
Seedling A - Coleoptiles tip was cut off, metal block placed, then tip placed back.
Seedling B - Coleoptiles tip was...(Solved)
Pea seedlings were treated as follows;
Seedling A - Coleoptiles tip was cut off, metal block placed, then tip placed back.
Seedling B - Coleoptiles tip was cut off, agar block placed then tip placed back.
Seedling C - Was left intact.
The seedlings A, B and C were placed in dark box with a small hole at one side as illustrated in the diagram below;
a) State what was being investigated in the set up above.
b) Using diagrams illustrate how the seedlings A, B and C appear after 48 hours.
c) Explain the results in (b) above;
Date posted: September 18, 2019. Answers (1)
- In an experiment using germinating seeds, it was found that 18cm3 of carbon (IV) oxide was released while 17.6cm3 of oxygen was used.
a) Calculate the...(Solved)
In an experiment using germinating seeds, it was found that 18cm3 of carbon (IV) oxide was released while 17.6cm3 of oxygen was used.
a) Calculate the respiratory quotient (RQ).
b) State the type of respiration occurring.
c) What is the likely respiratory substrate?
Date posted: September 18, 2019. Answers (1)
- Name an hormone that controls the formation of abscission layer in leaves and fruits.(Solved)
Name an hormone that controls the formation of abscission layer in leaves and fruits.
Date posted: September 18, 2019. Answers (1)
- The following process takes place in a plant organelle.
Water ? Hydrogen atoms + Oxygen(Solved)
The following process takes place in a plant organelle.
Water → Hydrogen atoms + Oxygen
i) Identify the organelle in which the process takes place.
ii) Name the process.
iii) State two conditions required for the process to take place.
Date posted: September 18, 2019. Answers (1)
- The figure represents different types of muscles. Study them carefully and answer the questions that follow.(Solved)
The figure represents different types of muscles. Study them carefully and answer the questions that follow.
(i) Identify the muscles labelled C and B.
(ii) Using observable features only; state two differences between muscles labelled B and D.
(iii) State one function of each of the muscles labelled B and C.
(iv) Give one adaptation of a muscle labelled C to its function.
Date posted: September 18, 2019. Answers (1)
- Photographs B, C and D below represent support structures in plants. Use them to answer the questions that follow.(Solved)
Photographs B, C and D below represent support structures in plants. Use them to answer the questions that follow.
(i) Name the support structure represented by photograph B
(ii) Explain briefly how the coiling in photograph B occurs
(iii) Name the structures labeled L on photograph C.
iv). Photograph D is a magnified photomicrograph of support tissues found in part x of photograph C. Give the name of the tissue labeled t.
(vi) Describe the structure of the cells of the tissue named in (a) (iv) above
Date posted: September 18, 2019. Answers (1)
- a)Name the excretory product produced in the liver and used in the intestine.
(b) State two functions of the waste product named in (a) above.(Solved)
a)Name the excretory product produced in the liver and used in the intestine.
(b) State two functions of the waste product named in (a) above.
Date posted: September 18, 2019. Answers (1)