(a) Axis
(b) Has odontoid process.
sharon kalunda answered the question on March 21, 2019 at 14:22
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Three tubes each containing 1ml saliva and 1ml water were incubated in water baths at different temperatures as shown in the diagram below for 30...
(Solved)
Three tubes each containing 1ml saliva and 1ml water were incubated in water baths at different temperatures as shown in the diagram below for 30 minutes. Another one tube containing 1ml starch solution was incubated for the same length of time in each water bath. The contents of the two tubes in each water bath was then mixed and incubated for further 30 minutes.The content of each tube was then tested for starch using iodine solution.
a) What was the aim of the experiment?
(b) Why was it necessary to incubate the tubes for 30 minutes before mixing their contents?
(c) State the colour changes you would expect to observe after adding iodine solution.
(d) Account for the expected observations.
Date posted:
March 21, 2019
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Answers (1)
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Sickle cell anaemia is a hereditary disease due to a recessive gene which changes normal haemoglobin (Hb – A) to abnormal
haemoglobin (Hb – S). The...
(Solved)
Sickle cell anaemia is a hereditary disease due to a recessive gene which changes normal haemoglobin (Hb – A) to abnormal
haemoglobin (Hb – S). The red blood cells of people with sickle cell anaemia are sickle shaped.
(a) What are the possible phenotypes of the offsprings of a man who is heterozygous and a woman who is also heterozygous?
Show your working.
(b) Sickle cell trait is more prevalent in tropical countries than in temperate countries. Give an explanation for this observation.
Date posted:
March 21, 2019
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Answers (1)
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Below is a diagram of a sperm cell.
(Solved)
Below is a diagram of a sperm cell.
a) Identify parts labeled X and Y.
(b) Explain how parts W and Z adapt the cell to its function.
(c) Using letter P identify or label on the diagram the part of the cell rich in DNA.
(d) State the function of part X.
Date posted:
March 21, 2019
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Answers (1)
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The figure shown below represents a kidney nephron. Use it to answer the questions that follow.
(Solved)
The figure shown below represents a kidney nephron. Use it to answer the questions that follow.
(a) (i) X is made up of a tuft of capillaries. How do they differ from other capillaries in the body?
(ii) What structural difference exist between W and Z?
(iii) State the significance of the difference stated in (a) (ii) above.
(b) State three adaptations that enable P to perform its function.
(c) What is counter flow and in which part of the nephron does it occur.
Date posted:
March 21, 2019
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Answers (1)
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An experiment was carried out to investigate the effect of hormones on growth of lateral buds of three pea plants.
The shoots were treated as follows.
(a)...
(Solved)
An experiment was carried out to investigate the effect of hormones on growth of lateral buds of three pea plants.
The shoots were treated as follows.
(a) Shoot A – Apical bud was removed.
(b) Shoot B – Apical bud was removed and gibberellic acid placed on the cut shoot.
(c) Shoot C – Apical bud was left intact.
The lengths of the branches developing from the lateral buds were determined at regular intervals. The results obtained are shown in the table below.
(i) Using the same axes, draw graphs to show the lengths of branches against time.
(ii) (a) What was the length of the branch in Shoot B on the 7th day?
(b) What would be the expected length of the branch developing from Shoot B on the 11th day?
(iii) Account for the results obtained in the experiment.
(iv) Why was Shoot C included in the experiment?
(v) What is the importance of gibberellic acid in agriculture?
vi)State two physiological processes that are brought about by the application of gibberellic acid on plants.
Date posted:
March 21, 2019
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Answers (1)
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Describe the role of hormones in the mammalian female reproductive cycle.
(Solved)
Describe the role of hormones in the mammalian female reproductive cycle.
Date posted:
March 21, 2019
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Answers (1)
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The diagram shown below represents a male reproductive system.
(Solved)
The diagram shown below represents a male reproductive system.
(a) Name the structure labelled X.
(b) Name two substances that pass through structure labelled Y.
Date posted:
March 21, 2019
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Answers (1)
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The set up shows an experiment to investigate photosynthesis.
(Solved)
The set up shows an experiment to investigate photosynthesis.
i) What gas was collected in the test tube?
ii) What was the role of sodium hydrogen carbonate in the experiment?
Date posted:
March 21, 2019
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Answers (1)
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Which two classes of phylum arthropoda have their head fused with the thorax?
(Solved)
Which two classes of phylum arthropoda have their head fused with the thorax?
Date posted:
March 21, 2019
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Answers (1)
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What biological knowledge or study is required in dealing with locusts that infest a maize crop.
(Solved)
What biological knowledge or study is required in dealing with locusts that infest a maize crop.
Date posted:
March 21, 2019
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Answers (1)
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Describe an experiment you would carry out to demonstrate that xylem transports water
(Solved)
Describe an experiment you would carry out to demonstrate that xylem transports water
Date posted:
March 19, 2019
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Answers (1)
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What will happen in the stomach during digestion if mucus is absent?
(Solved)
What will happen in the stomach during digestion if mucus is absent?
Date posted:
March 17, 2019
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Answers (1)
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What determines the type or mode of placentation of a flower ovary?
(Solved)
What determines the type or mode of placentation of a flower ovary?
Date posted:
March 17, 2019
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Answers (1)
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What is nitrogenous waste?
(Solved)
What is nitrogenous waste?
Date posted:
March 16, 2019
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Answers (1)
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(a)Explain the role of pituitary gland in reproduction.(ii)State one function of thyroxine.
(Solved)
(a)Explain the role of pituitary gland in reproduction.
(b)State one function of thyroxine.
Date posted:
March 15, 2019
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Answers (1)
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Name the enzymes that complete carbohydrate digestion in the ileum of humans.
(Solved)
Name the enzymes that complete carbohydrate digestion in the ileum of humans.
Date posted:
March 15, 2019
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Answers (1)
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Explain why the heart of a frog continues to beat after the head has been cut off.
(Solved)
Explain why the heart of a frog continues to beat after the head has been cut off.
Date posted:
March 15, 2019
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Answers (1)
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Name the two bones that form the ball and socket joint in the upper limb of a mammal.
(Solved)
Name the two bones that form the ball and socket joint in the upper limb of a mammal.
Date posted:
March 15, 2019
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Answers (1)
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Explain why the leaf of a bean plant wilts in the afternoon on hot days but appear turgid early the following morning.
(Solved)
Explain why the leaf of a bean plant wilts in the afternoon on hot days but appear turgid early the following morning.
Date posted:
March 15, 2019
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Answers (1)
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State three characteristics of class diplopoda.
(Solved)
State three characteristics of class diplopoda.
Date posted:
March 15, 2019
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Answers (1)