Get premium membership and access questions with answers, video lessons as well as revision papers.
- A student mixed a sample of urine from a person with Benedict’s solution and heated, the colour
changed to orange.
(a) What was present in the urine...(Solved)
A student mixed a sample of urine from a person with Benedict’s solution and heated, the colour
changed to orange.
(a) What was present in the urine sample?
(b) What did the student conclude on the health status of the person?
(c) Which organ in the person may not be functioning properly?
Date posted: June 17, 2019.
- Describe how ingestion of very salty food may reduce the amount of water excreted in urine.(Solved)
Describe how ingestion of very salty food may reduce the amount of water excreted in urine.
Date posted: June 17, 2019.
- Name two substances that are not found in urine of a healthy person(Solved)
Name two substances that are not found in urine of a healthy person
Date posted: June 17, 2019.
- Explain the following:-
i) Fresh water fish excrete ammonia
ii) Glucose is absent in urine yet present in glomerular filtrate(Solved)
Explain the following:-
i) Fresh water fish excrete ammonia
ii) Glucose is absent in urine yet present in glomerular filtrate
Date posted: June 17, 2019.
- Explain why resistance to antibiotics is considered as an example of evolution(Solved)
Explain why resistance to antibiotics is considered as an example of evolution
Date posted: June 15, 2019.
- In a breeding experiment, plants with red flowers were crossed. They produced 123 plants with red flowers and 41 with white flowers:
(a) Identify the recessive...(Solved)
In a breeding experiment, plants with red flowers were crossed. They produced 123 plants with red flowers and 41 with white flowers:
(a) Identify the recessive trait
(b) Give a reason for your answer
Date posted: June 15, 2019.
- Explain why insecticides become ineffective against insects if used for several years in succession (Solved)
Explain why insecticides become ineffective against insects if used for several years in succession
Date posted: June 15, 2019.
- Briefly explain the term “survival for the fittest” as used in Darwin’s theory of natural selection(Solved)
Briefly explain the term “survival for the fittest” as used in Darwin’s theory of natural selection
Date posted: June 15, 2019.
- Explain why certain drugs become ineffective in curing a disease after many years of use (Solved)
Explain why certain drugs become ineffective in curing a disease after many years of use
Date posted: June 15, 2019.
- All insects are believed to have arisen from a common ancestor. However, modern insects differ widely in a variety of ways such as in the...(Solved)
All insects are believed to have arisen from a common ancestor. However, modern insects differ widely in a variety of ways such as in the adaptation of their mouthparts for different modes of feeding. What kind of evolution is this?
Date posted: June 15, 2019.
- Distinguish divergent and convergent evolution(Solved)
Distinguish divergent and convergent evolution
Date posted: June 15, 2019.
- Give two factors that determine water reabsorption in the distal convoluted tubule(Solved)
Give two factors that determine water reabsorption in the distal convoluted tubule
Date posted: June 15, 2019.
- Distinguish between the struggle for existence and survival for the fittest as used in the theory of natural selection(Solved)
Distinguish between the struggle for existence and survival for the fittest as used in the theory of natural selection
Date posted: June 15, 2019.
- State any two similarities in structure between Homo erectus and Homo Sapiens(Solved)
State any two similarities in structure between Homo erectus and Homo Sapiens
Date posted: June 15, 2019.
- State role of cardiac sphincter in the stomach.(Solved)
State role of cardiac sphincter in the stomach.
Date posted: June 15, 2019.
- Distinguish between camouflage and mimicry.(Solved)
Distinguish between camouflage and mimicry.
Date posted: June 15, 2019.
- Give two examples of adaptive radiation in animals. (Solved)
Give two examples of adaptive radiation in animals.
Date posted: June 15, 2019.
- Name one method that would be used to estimate the population of small fish in the ecosystem(Solved)
Name one method that would be used to estimate the population of small fish in the ecosystem
Date posted: June 15, 2019.
- State the role of Leguminous plants in an ecosystem(Solved)
State the role of Leguminous plants in an ecosystem
Date posted: June 15, 2019.
- State three disadvantages of using synthetic pesticides over Biological control.(Solved)
State three disadvantages of using synthetic pesticides over Biological control.
Date posted: June 15, 2019.
- Describe how a population of grasshoppers in a given area can be estimated(Solved)
Describe how a population of grasshoppers in a given area can be estimated
Date posted: June 15, 2019.
- Explain how food as a factor regulates the population of animals in an ecosystem(Solved)
Explain how food as a factor regulates the population of animals in an ecosystem
Date posted: June 15, 2019.
- Apart from mere observation of actual feeding suggest two methods that can be used to determine the type of food eaten by animals(Solved)
Apart from mere observation of actual feeding suggest two methods that can be used to determine the type of food eaten by animals
Date posted: June 15, 2019.
- What are the two main components of an ecosystem?(Solved)
What are the two main components of an ecosystem?
Date posted: June 15, 2019.
- To estimate the population size of crabs in a certain lagoon, traps were laid at random. 400 crabs
were caught, marked and released back into the...(Solved)
To estimate the population size of crabs in a certain lagoon, traps were laid at random. 400 crabs
were caught, marked and released back into the lagoon. Four days later, traps were laid again and
360 crabs were caught. Out of the 360crabs, 90 were found to have been marked
(i) Calculate the population size of the crabs in the lagoon
(ii) What is the name given to this method of estimating the population size
Date posted: June 15, 2019.
- What do you understand by the term trophic level?(Solved)
What do you understand by the term trophic level?
Date posted: June 15, 2019.
- A fish farmer wanted to know the number of fish in a pond. He collected 10 fish from the pond
and labeled each, by a tag...(Solved)
A fish farmer wanted to know the number of fish in a pond. He collected 10 fish from the pond
and labeled each, by a tag label on its fin and returned the ten fish to the pond to mix with
other fish . When he later collected 50 fish from the pond, he found only four of them had labels
a) Estimate the total number of fish in the pond (show your workings)
b) What two assumptions are being made in this methods of estimating population
Date posted: June 15, 2019.
- An investigation was carried out on a terrestrial ecosystem. The population sizes and species biomass were determined and recorded as shown in the table...(Solved)
An investigation was carried out on a terrestrial ecosystem. The population sizes and species
biomass were determined and recorded as shown in the table
a) If these organisms had a feeding relationship, construct a simple food chain involving all the organisms
b) Construct pyramid of numbers using the data provided above
c) State one disadvantage of using pyramid of number in expressing feeding relationships in ecological ecosystem
Date posted: June 15, 2019.
- In a certain school Form three class did an experiment to estimate the number of Tilapia
in their fish pond. 725 tilapia were netted marked and...(Solved)
In a certain school Form three class did an experiment to estimate the number of Tilapia
in their fish pond. 725 tilapia were netted marked and released.
a) State the method used in this exercise
b) Calculate the tilapia population.
c) State two assumptions made by the students during the investigation
Date posted: June 15, 2019.
- Use the food web below to answer the questions that follow:-
(a) Construct a food chain ending with crocodile as a quartenary consumer
(b) Name the organisms...(Solved)
Use the food web below to answer the questions that follow:-
(a) Construct a food chain ending with crocodile as a quartenary consumer
(b) Name the organisms in the food web hat has only one predator
Date posted: June 15, 2019.