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How to respond to biological questions

By Outworkerpost Support  1 year, 2 months ago

toad matingPhoto: toad mating


Being able to respond to question alone is not enough one needs to have adequate background knowledge related to the topics addressed in the question. As you go through take your time to go through your notes to have a deeper understanding.

1.      Differentiate between growth and development?

Answer: Growth is the permanent increase in size; development is the differentiation of cells to improve quality.

2.      List three characteristics of living organisms

Answer: irritability, nutrition/excretion, Gaseous exchange, respiration, reproduction, growth and development

3.      Define the following ecological terms


a.       Biomass: Total dry weight of organism at a particular trophic level.

b.      Ecosystem: A self-sustaining system made up of biotic and abiotic factors interacting with each other.

c.       Carrying capacity: Number of organism a particular area can comfortably support without depleting its resources.  

4.      a) Name the method that can be used to calculate the total number of fish in a pond

Answer: Capture and recapture method

b) State two adaptive features of the parasites Ascaris Lumbricoides

Body coat that is resistant to host enzymes

Larva is able to form a cyst to avoid attack by chemicals in the host

5.      Define the term pollination

Answer: Transfer of pollen grains from the anther to the stigma

6.      State two factors which determine energy requirement in humans

Answer: Age, sex, body size, level of work or activity, basal metabolic rate

7.      Give one function of each of the following reproductive organs


a.       Testes: Formation of sperm/ production of sex hormones

b.      Ovaries: Formation of ova/ production of sex hormones

8.      State three characteristics of kingdom plantae


Practice both sexual and asexual reproduction


9.      State three characteristics of an efficient respirator (gaseous exchange) surface.

Large surface area


Thin membrane

Highly vascularized


Insect pollinated flowersWind-pollinated flowers
With nectar
Dull colored corolla
Brightly colored corollaTiny flowers
Large flowersWithout nectar
ScentedNot scented
Large sticky pollen grainsSmall, light, feathery pollen grains
Short stamensLong stamens
Small anthers firmly fixed onto filamentLarge loosely attached anthers


11.  An organism was found to have the following characteristics:

Jointed appendages

Body covered with a hard exoskeleton made of chitin

Lays eggs which later hatch into young ones

Has compound eyes

Body is segmented

a.       Name the phylum to which the organism belongs? Arthropoda

b.      To which class does the organism belong? Insecta

c.       Give an example of an organism that belongs to this class?  Bee, moth, butterfly, cockroach or locust

12.  a) Explain the meaning of the term double circulation in mammals 

        Answer: passage of blood through the heart before it goes back to the tissue

b) Name the two forms of circulation involved in double circulation: pulmonary circulation

Systematic circulation

13.  Explain the meaning of the term test cross?

A cross carried out to determine the genotype of the spring showing the dominant character, homozygous or heterozygous

What is stimulus?

Change or variation in a specific environmental condition such as temperature

1.      Draw and label a motor neurone?

1.      Name the chromosomes which determine sex in human? 

Answer: sex chromosomes

2.      List three pieces of evidence for organic evolution?

Answer: fossil records

Geographical distribution

Comparative anatomy

Comparative embryology

Cell biology


3.      Briefly explain the meaning of the term apical dominance?

Answer: Increase in height or length of plant at the expense of lateral buds

4.      a) Give one example of discontinuous variation?


Eye color or finger print

b) Explain the meaning and give one example of continuous variation

I) meaning: variation in which many intermediates exist between one extreme to the other.  

            II) Example: height, weight and skin color in humans

5.      Give three differences between aerobic and anaerobic respiration

Answer: Aerobic respiration requires oxygen, while anaerobic respiration does not

Aerobic respiration produces more energy than anaerobic respiration

Aerobic respiration takes place mainly in the mitochondria while anaerobic respiration occurs in the cytoplasm

6.      State two factors which affect the rate of breathing in humans

Answer: Activity


Health status

7.      List three pieces of evidence for organic evolution

Fossil records

Geographical distribution

Comparative anatomy

Comparative embryology

Cell biology


8.      Explain why Lamarck’s theory of inheritance was discarded?


Answer: Change due to use or disuse do not change the genotype and thus cannot be inherited


1.      Name the structure labelled A-F in the following figure.

Answer: A: Glomerulus

B: Bowman’s capsule

C: Loop of Henle

D: Proximal convoluted tubule

E: Distal convoluted tubule

F: Collecting duct


1.      In an experiment, a seedling was placed in a horizontal position and left for several days. Observation were made and the result was as shown in the figure below.

Briefly explain the result shown in Q

Answer: Roots requires very low concentration of auxins. Gravity pulls auxins to lower part. Upper part thus undergoes greater growth, therefore the root bends downwards

1.      State two application of anaerobic respiration in industry

Answer: manufacture of alcoholic drinks

Production of organic acids


Synthesis of cheese, butter and yoghurt

2.      Explain the necessity for locomotion in animals

Answer: For the animal to be able to search for food, reproductive mates and more suitable environmental factors

3.      Name two functions of the mammalian ear



4.      State three distinguishing features of the atlas bone of the vertebral column

Wing-like transverse processes

Absence of centrum

Presence of vertebral canals in transverse processes

5.      Give three function of the endoskeleton

Support organism

Facilitate movement

Protects organs such as heart and brain


Hold organs in place


1.      Draw and label a finned fish

1.      Name the process by which the nephron removes wastes and other material from blood into the Bowman’s capsule 

Answer: Ultrafiltration 

The illustration below shows a human eye that is defective 

a) Name the eye defect shown? Short-sightedness (myopia)

b) How would this defect be corrected? Concave (diverging) lens

34. Using arrows only, indicate the pathway of blood through the mammalian heart on the illustration below