Also it is the flow and buoyancy of water that keeps the gill filaments apart so that gas exchange can occur You could use parts of this one The human blood carries all materials needed that for the cells or released by cells these include oxygen or carbon dioxide depending on where it is, nutrients and hormones. Sign-up here it’s free. Fish, with a long flat body shape and the buoyancy of water reduced effect of gravity means that the low pressure system is sufficient. Find what you need to know Choose a subject Choose a subject Choose a subject – Choose an achievement standard -.

Also it is the flow and buoyancy of water that keeps the gill filaments apart so that gas exchange can occur And why would foregut herbivores use their caecum more than hindgut herbivores? Each year the questions for the animal and plant diversity papers are slightly different wording but they still require similar things ie to describe the structures, explain their functions and discuss the reasons for the diversity. U can memorize your “essay” if it suits you! Al three involve diffusion; oxygen diffuses from the water to the blood, and carbon dioxide diffuses from the blood to the water in the external gills of the fish, oxygen and carbon dioxide diffuse in and out of the tissues in the tracheal system of the insect and oxygen and carbon dioxide diffuse in and out of the blood from the lung in the human.

The advantage of the system being internal is that the lungs are always moist and are protected by the ribcage; the worm and the insect by contrast have little protection from physical damage. Not enough for explanation “In comparison the insect, fish and human are very different.

ncea gas exchange essay

The circulatory system takes the oxygenated blood from gas exchange around the body to the cells for diffusion using haemoglobin. In summary, each aminal discussed has a gas exchange system to suit their particular ecological niche and level of activity.


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ncea gas exchange essay

I think you are right in saying that is not critical but definitely helpful She taught us that we should explain excchange and how structures exist as they do to achieve with merit. In order to maintain the concentration gradient fish use the counter current system, so ensuring as efficient gas exchange as possible.

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The blood travels in arteries when oxygenated and in veins when deoxygenated. This is because they can increase their alveoli numbers, and their method of gas exchange does not depend on the size of their bodies; only the alveoli. Most herbivores have a relatively large cecum, and exclusive carnivores have a smaller cecum or none nce all.

The blood flow is controlled and is distributed via various blood vessels capillary networks. Gas exchange Hey STs!


Essays are not required An advantage of the tracheal system and lungs over gills is that since air has a much higher oxygen concentration than water, it can diffuse much faster and more easily and therefore less ventilation is needed.

They both digest cellulose! If you have any suggestions for making it shorter I’m all ears.

Which one do you think would be better the leave out with effecting my mark? Insects In insects exhcange. Thanks for your advice ST.

Gas Exchange – WGHS BAP Year 12

Also, what’s the purpose of an oesophagus? The swimming action of fish muscles however, push the blood back towards the heart.

Therefore the insects have a very efficient gas exchange system which is suitable for most environments, but restricts size. Gas exchange in insects involves air entering the tracheae through the spiracles openingspassing through the smaller tracheoles, and terminating in the tissues.

They are not large organisms so the gas exchange system they have can deliver enough oxygen and CO2 even for organisms that fly.


Earthworms have a small nutritional and energy requirement. Insects, however have a tracheal system that takes the gases directly to body cells allowing for more rapid transport than fish and mammals, and this means that insects have the higher metabolic rates needed for their active lifestyles.

Unlike humans and insects, they move slowly and therefore do not require a large amount of oxygen. Oxygen diffuses into the tissues exchxnge carbon dioxide diffuses out. It is a single circulation which means the blood is only pumped once in its way around the system.

This exchnage the constant diffusion of oxygen into the blood stream as a concentration gradient is maintained; low levels of oxygen in the blood are coming into contact with high levels of oxygen in water flowing in the opposite direction.

Diversity in the gas exchange systems of fish, insects and humans is related to differences in the terrestrial and aquatic environments.

Earthworms are relatively simple animals, and their gas exchange system is simple also. Their gas exchange essxy is well suited to their needs as it delivers oxygen straight to the muscles where it is needed. As cows are herbivores and eat plant material mainly grassthat contains tough cellulose, they have developed adaptations that allow them to get as much nutrients as they can out of this “low grade vegetation: Fish In bony fish eg salmon gas exchange occurs as such: The Caecum is not necessary for foregut digesters however some microbial action could take place there.