a(i) Lag phases; Dry mass increases slowly; became in plant has not developed
leaves; for photosynthesis hence is depending on stored food;
(ii) Expontial phase; Rapid growth /increase in dry mass, leaves developed; photosynthesis taking place leading to accumulation of food and rapid cell division / plant adapted to the environment
(iii) Death phase/ senescence; Negative growth/decrease in dry mass as some tissues die after reaching maximum maturity; Fall in photosynthesis activity; toxic wastes poison tissues;
(b)
(i) When dry mass was first recorded/at germination
(ii) Dry mass would decrease first because food is oxidized to produces energy; water and carbon dioxide/utilized in respiration;
(c)
(i) Harvest every week about five seedlings; dry in oven to a constant dry mass; Calculate the average mass for one seedling and record the results.
(ii) Advantage; Dry mass is not affected by environmental conditions while fresh weight is dependent on the amount of water in the plant which fluctuate with environmental factors affecting transpiration rate
marto answered the question on October 7, 2019 at 09:30
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The experiment set – up below was designed to investigate an aspect of germination.
(Solved)
The experiment set – up below was designed to investigate an aspect of germination.
a) Why was potassium hydroxide pellets used in this experiment?
b) What was the role of moist cotton wool in this experiment?
c) i) By means of an arrow, indicate on the diagram the direction in which red dye would move
during the experiment.
ii) Give reason for your answer in c(i) above.
d) Other than the factor investigated above, state any other one factor necessary for germination
process.
Date posted:
October 7, 2019
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Answers (1)
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The diagram below represents a stage during the process of germination.
(Solved)
The diagram below represents a stage during the process of germination.
(a) (i) Name the type of germination illustrated in the diagram
(ii) Give a reason for your answer in (a) (i) above.
(b) Give two functions of the part labelled X
Date posted:
October 7, 2019
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Answers (1)
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The diagram below represents a growth pattern of arthropods.
(Solved)
The diagram below represents a growth pattern of arthropods.
(a) Name the type of growth pattern represented on the graph.
(b)Identify the process represented by X.
(c) Which hormone is responsible for process at X in (b) above?
Date posted:
October 7, 2019
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Answers (1)
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The illustration below represents an eye defect.
(Solved)
The illustration below represents an eye defect.
Date posted:
October 7, 2019
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Answers (1)
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An experiment was carried out to investigate the rate of growth of pollen tube against time.
The results are shown in the table below.
(Solved)
An experiment was carried out to investigate the rate of growth of pollen tube against time.
The results are shown in the table below.
(b) (i) At what intervals was the growth of the pollen tube measured?
(ii) What was the length of pollen tube at; 130 minutes
(iii) At what time was the length of the pollen tube 18mm?
(iv) With reasons, describe the growth pattern of the pollen tube between:
- 0 to 120minutes
- Reason
- 120 to 180 minutes
- Reason
v) State the importance of the growth of pollen tube to the plant
(c) State the changes that take place in a flower after fertilization
Date posted:
October 7, 2019
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Answers (1)
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The diagram below represents female reproductive system.
(Solved)
The diagram below represents female reproductive system.
a) Name the part labeled; A, B, C and D
b) State two functions of structure A
c) How is part C adapted to its function?
d) Of what significance is part E to reproduction?
Date posted:
October 7, 2019
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Answers (1)
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Why is immunization against diseases encouraged by the government?
(Solved)
Why is immunization against diseases encouraged by the government?
Date posted:
October 7, 2019
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Answers (1)
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What do you understand by the word Acquired Immunity Deficiency Syndrome (AIDS)?
(Solved)
What do you understand by the word Acquired Immunity Deficiency Syndrome (AIDS)?
Date posted:
October 7, 2019
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Answers (1)
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State two ways by which the HIV spread may be controlled through patients in hospitals.
(Solved)
State two ways by which the HIV spread may be controlled through patients in hospitals.
Date posted:
October 7, 2019
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Answers (1)
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The diagram below represents some hormones, their sources and functions in mammals.
(Solved)
The diagram below represents some hormones, their sources and functions in mammals.
a) Name the hormones I, II and III
b) Name hormones IV and state its function
c) Name the control labelled A & B
d) Name one secondary sexual characteristic common to both males and females
Date posted:
October 7, 2019
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Answers (1)
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The diagrams below represent two gynoecia A and B obtained from two different plants.
(Solved)
The diagrams below represent two gynoecia A and B obtained from two different plants.
(a) What name is given to;
Gynoecium A?
Gynoecium B?
(b) State the observable difference between the gnoecia A and B
(c) State the role played by Heterostyly in plants.
Date posted:
October 7, 2019
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Answers (1)
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The diagram below shows a stage during cell division.
(Solved)
The diagram below shows a stage during cell division.
(i) Name the stage of cell division
(ii) Give a reason for your answer
(b) Name two structures in plants where male and female gametes are produced
Date posted:
October 7, 2019
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Answers (1)
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Describe the possible effects of discharging hot effluent from a factory into a slow flowing river.
(Solved)
Describe the possible effects of discharging hot effluent from a factory into a slow flowing river.
Date posted:
October 7, 2019
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Answers (1)
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What is the main product of the dark stage of photosynthesis?
(Solved)
What is the main product of the dark stage of photosynthesis?
Date posted:
October 7, 2019
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Answers (1)
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State the role of centrioles during cell division.
(Solved)
State the role of centrioles during cell division.
Date posted:
October 7, 2019
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Answers (1)
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The diagram below illustrate a process in a given species of organism.
(Solved)
The diagram below illustrate a process in a given species of organism.
a) Name the organism that undergoes the process above.
b) Identify the process shown to be taking place.
Date posted:
October 7, 2019
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Answers (1)
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The diagram below shows a pollen – tube entering the ovule of a flowering plant.
(Solved)
The diagram below shows a pollen – tube entering the ovule of a flowering plant.
a) Name the parts labeled A, B and D
b) Name the kind of fertilization exhibited by the above flowering plant.
Date posted:
October 7, 2019
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Answers (1)
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State three ways in which flowers parent self pollination.
(Solved)
State three ways in which flowers parent self pollination.
Date posted:
October 7, 2019
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Answers (1)
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Name the hormone that Stimulates the disintegration of the corpus inteum when fertilization fails to take place.
(Solved)
Name the hormone that Stimulates the disintegration of the corpus inteum when fertilization fails to take place.
Date posted:
October 7, 2019
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Answers (1)
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Name two mechanisms that hinder self fertilization in flowering plants.
(Solved)
Name two mechanisms that hinder self fertilization in flowering plants.
Date posted:
October 7, 2019
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Answers (1)