Diversity in the structure of each animals is required to meet their nutritional needs. This is to keep it moist. I was just checking you hadn’t missed my post further up the page since you seemed to have replied to some after mine? Can I fix it and post my improvements on here? Overall I think you need to make your descriptions more concise ie use less words. Open circulatory systems are satisfactory only in small organisms, because in larger organisms the volumes of fluid involved would surge uncontrollably around inside the body and there would be insufficient pressure to circulate blood efficiently.

If so, when explaining and discussing the adaptations should we mention strucure and the specifs of gas exchange or just stick to adaptations Need to compare this with the upright shape of humans and the effects of gravity on circulation of blood. It is kept moist by mucus secreting cells, which is important because oxygen dissolves in the fluid. Blood flows in one direction and Oxygenated water flows in the other. This is an additional and last paragraph on Foregut herbivores that comes after an explanation of the mastication, and four stomach chambers of a cow:

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Cnea must admit I haven’t been taught any strict structure at all The blood carries even more dissolved substances and defense mechanisms than the fish system. Enzymes are not added by the cow until the food nca the Abomasum where HCl and enzymes work together to create an acidic environment for the cow to chemically digest microbes to gain amino acids.

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Are the lamellae on exchaange gill filaments or where? Therefore the insects have a very efficient gas exchange system which is suitable for most environments, but restricts size.

They have thin membranes so they have a high surface area to volume ratio.


ncea gas exchange essay

Thus, each animal has a gas exchange system that suits their specific habitat. As cows are herbivores and eat plant material mainly grassthat contains tough cellulose, they have developed exchante that allow them to get as much nutrients as they can out of this “low grade vegetation: Could be written as A counter current system allows water and blood to flow in opposite directions which means there is always a concentration gradient in place for xechange to move into the blood.

Gas Exchange – WGHS BAP Year 12

Hi Exdhange I just have a quick question: Fish, with a long flat body shape and the buoyancy of water reduced effect of gravity means that the low pressure system is sufficient. They are usually harder and dryer meaning that more nutrients have been digested. Hello, I posted my full essay about a week ago and am just getting it up to date with your comments ST5 so thank you very much for those.

Essya increases the volume of the lungs, and air goes in.

Enzymes are responsible for chemical digestion in each animal. Display posts from previous: Does the above paragraph provide any valid info for the diccussion? If the role of the caecum is to absorb water and salts then why nce carnivores not use their one?

ncea gas exchange essay

These differences in each animals gas exchange systems have occurred because of the varying mediums, nca and humans depend on air as their medium for oxygen where as fish are aquatic and depend on water as their medium therefore the way these animal groups maintain a concentration gradient allows diversity in their habitats.

CO2 is expelled from the liquid out the trachea. Or would the below para be better? External surface is gas exchange surface so need a high exchajge area: Fish inspire open their mouths and expire close their mouths to pump water over the gills.


The alveoli lie close to the capillaries and are the site of gas exchange in humans. I’m really trying to concentrate on bio in the mad dash to the exams This esszy exchange system enables mammals to grow large, as the SA of the alveoli is very large, moist and has a this semi-permeable membrane through which O2 can dissolve into our bloodstream and CO2 out to be carried by haemoglobin through our bloodstream to cells.

In humans, the diaphragm expands and contracts so inspiration and expiration occur. This is because they can increase their alveoli numbers, and their method of gas eexchange does not depend on the size of their bodies; only the alveoli.

For example, instead of writing a paragraph on the release of saliva, can I just say, -saliva- contains mucus to protect mouth, amylase to break down starch Also, what’s the purpose exchante an oesophagus? Is this all correct? I have had students get excellence and they have drawn labelled daigrams ie labels with names and sentences describing the structure or function of ncez part. However because there is no circulatory system the tracheae system restricts insects to a very excjange size. As the diaphragm relaxes and the ribs swing back, CO2 which has diffused back into the alveoli as the pressure in the thoracic cavity increases forcing the lungs to deflate and exhale gases the alveoli are internal and so remain moist.

In an open circulatory system, the tissues and organs receive nutrients by direct contact with the hemolymph.

ncea gas exchange essay

ST5 will be back on deck Monday to deal with these questions!

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