a) The cell membrane is semi permeable- The pores that occur on the cell membrane allows the passage of the small size molecules but does not allow the passage of the large sized molecules.
Such a membrane is said to be selectively permeable or semi-permeable. In particular, when a cell is surrounded by a dilute sugar solution, the small sized water molecules will enter the cell but the larger sugar molecules will not pass through the cell membrane.
In contrast, the cell wall is permeable as it allows both sugar and water molecules to pass through it; it has larger pores. This property of selectively permeability enables the cell membrane to select what enters and leaves the cell.
b)The cell membrane is sensitive to changes in temperature and pH- Cell membranes are made up of protein. Proteins are adversely affected by extreme changes in temperature and pH.
Changes in temperature and pH will alter the structure of the cell membrane thereby hindering the normal functioning of the cell membrane. High temperature denatures (destroys) the proteins thereby impairing the functions of the cell membrane.
c)The cell membrane possesses electric charges- The cell membrane has both positive and negative charges. These charges affect the manner in which substances move in and out of the ells. The charges also enable the cell to detect changes in the environment.
simiyu kelly answered the question on September 15, 2017 at 11:34
- Describe the structure of cell membrane(Solved)
Describe the structure of cell membrane
Date posted: September 15, 2017. Answers (1)
- a) What is magnification? (b)Give the formula used to calculate magnification in a light microscope(Solved)
a. What is magnification?
b. Give the formula used to calculate magnification in a light microscope
Date posted: September 15, 2017. Answers (1)
- a) What is a microscope? (b)Name the types of microscopes. (c) State the purpose of using a light microscope. (d) Explain the procedure followed when using a...(Solved)
a. What is a microscope?
b. Name the types of microscope
c. State the purpose of using a light microscope
d. Explain the procedure followed when using a microscope
e. State the precautions that are necessary when handling a microscope
Date posted: September 15, 2017. Answers (1)
- a) Define the term cell (b) What is cell biology?(Solved)
a. Define the term cell
b. What is cell biology?
Date posted: September 15, 2017. Answers (1)
- a) What is a species? (b) Name the major kingdoms used in classification(Solved)
a. What is a species?
b. Name the major kingdoms used in classification
Date posted: September 15, 2017. Answers (1)
- 1. (a) what is classification? (b) List the external features used to classify plants (c) List the external features used to classify animals...(Solved)
a. What is classification?
b. List the external features used to classify plants
c. List the external features used to classify animals
d. Give the reasons why classification is important
e. Name the taxonomic units of classification in descending order
Date posted: September 15, 2017. Answers (1)
- 1. (a) What is a hand lens? (b) How is a hand lens used? (c) When is a hand lens used? (Solved)
a. What is a hand lens?
b. How is a hand lens used?
c. When is a hand lens used?
Date posted: September 15, 2017. Answers (1)
- State the characteristics of living organisms.(Solved)
State the characteristics of living organisms.
Date posted: September 15, 2017. Answers (1)
- Explain the importance of biology.(Solved)
Explain the importance of biology.
Date posted: September 15, 2017. Answers (1)
- List the branches of biology.(Solved)
List the branches of biology.
Date posted: September 15, 2017. Answers (1)
- Define Biology.(Solved)
Define Biology.
Date posted: September 15, 2017. Answers (1)
- Describe how herbaceous plants obtain their support?(Solved)
Describe how herbaceous plants obtain their support?
Date posted: September 13, 2017. Answers (1)
- How are female parts of wind pollinated flowers adapted to perform their function?(Solved)
How are female parts of wind pollinated flowers adapted to perform their function?
Date posted: September 13, 2017. Answers (1)
- (a)Define nondisjunction? (b) Name two genetic disorders of the blood.(Solved)
(a) Define nondisjunction?
(b) Name two genetic disorders of the blood.
Date posted: September 13, 2017. Answers (1)
- Give three effects of over secretion of adrenaline?(Solved)
Give three effects of over secretion of adrenaline?
Date posted: September 13, 2017. Answers (1)
- What are the roles of each of the following on transmission of impulses:(i)Nodes of Ranvier (ii)Myelin Sheath (Solved)
What are the roles of each of the following on transmission of impulses:
i)Nodes of Ranvier
ii)Myelin Sheath
Date posted: September 13, 2017. Answers (1)
- State the three structural adaptations of the lungs in mammals(Solved)
State the three structural adaptations of the lungs in mammals
Date posted: September 13, 2017. Answers (1)
- (a)What is organic evolution (b)Briefly explain how the peppered moth (Biston betularia) shows natural selection (c)Distinguish between convergent and divergent evolution ...(Solved)
(a)What is organic evolution
(b)Briefly explain how the peppered moth (Biston betularia) shows natural selection
(c)Distinguish between convergent and divergent evolution
Date posted: September 13, 2017. Answers (1)
- Define the term: (i)Greenhouse effect (ii)Global warming(Solved)
Define the term:
i)Greenhouse effect
ii)Global warming
Date posted: September 13, 2017. Answers (1)
- (a) Give the importance of nitrogen cycle in the atmosphere(Solved)
(a) Give the importance of nitrogen cycle in the atmosphere
(b)What are the roles of the following organisms in an ecosystem?
i)Decomposers
ii)Detrivores
Date posted: September 13, 2017. Answers (1)