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Describe how the human body can prevent the entry of organisms that cause disease. Include physical barriers and chemical defences in your answer.

Physical barriers: skin to prevent entry of organisms into the bloodstream cilia lining the nasal passages / bronchi to prevent entry to lungs / remove mucus scabs to prevent entry of microorganisms into the...
KM
Answered by Khadija M. • Biology tutor
10518 Views

Which of the basic life processes is described here? The ability of multicellular organisms to regulate their internal environment so that it stays optimum for cellular survival.

Homeostasis
AM
Answered by Alice M. • Biology tutor
3366 Views

Explain the diffusion process of gas exchange in the lung during respiration

Oxygen and carbon dioxide, dissolved in water, are exchanged by diffusion in the lungs. Blood travelling to the lungs is deoxygenated and instead of oxygen, carbon dioxide is bound to the red blood cells. Th...
CR
Answered by Calum R. • Biology tutor
14221 Views

What are the stages of mitosis?

Prophase - everything in the cell duplicates, and the chromosomes condense Metaphase - chromosomes align in the middle of the cell and spindle fibres attach to the centromere (part holding the two sister chr...
AM
Answered by Anya M. • Biology tutor
3171 Views

What is the role of the myelin sheath in the transmission of electric impulses in the nervous system?

It is important to note that the IB syllabus expects the students to understand that "The myelination of nerve fibres allows for saltatory conduction." What this essentially means is, that the myel...
CS
Answered by Clara S. • Biology tutor
11078 Views