However, water also has a much lower concentration of oxygen than air creating difficulties for fish in terms of diffusion gradients. Here is a shortened version of the insect section You could use parts of this one Unlike worms and fish, mammals moistly live in a drying environment, so their gas exchange system, the lungs, is hidden deep in the body. A counter current exchange ensures that a concentration gradient is maintained between the blood and the water even when the blood is highly saturated with oxygen. I’m really trying to concentrate on bio in the mad dash to the exams

Also how many words should we be planning on writing for each animal group? Carbon dioxide exits the blood by the same process, and is exhaled. A bit confused about all that and even Wikipedia didnt help Structure of essays I am becoming increasingly confused when I read the responses the science teachers are giving in regards to peoples essays. Also, the way the cow regurgitates its food means that the partially digested cellulose is brought back into mouth for mastication, which further increases SA, thus further increasing microbe fermentation efficiency. It is important that you relate you answer to the question given and not just write a “prepared essay”. Hi, Yea, am having a bit of trouble writing within the 35minute time limit.

Are the lamellae essag the gill filaments or where? However if a fish was taken out of water, its gas exchange system would not function despite the increase in oxygen, for the system would not be supported, and as moisture would be lost, SA would decrease and diffusion would not occur, ceasing the counter current exchange system and preventing O2 being absorbed for gas exchange.

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They maintain a constant blood and body temperature which mean they can exploit extremes of the environment. We have taken many students through the steps of comparing the three groups for plants and animals – happy reading Once you’ve put something together we are more than happy to go from there Cheers ST The internal gas exchange organs are protected from the external environment, whereas the external gills of fish like salmon are more vulnerable.?


First two sentences are a good intro. If I picked one of the two paragraphs below which one would be better to leave out? They use high energy foods which get delivered to the cells by the Heamolymph. The blood carries even more dissolved substances gsa defense mechanisms than the fish system. Oxygen transportation uses diffusion and is carried out by the spiracles and trachea system.


In larger insects air sacs are also present and CO2 is expelled through a pumping body action. Their skin is adapted to their method of gas exchange as it is thin and nxea a rich supply of blood. The alveoli lie close to the capillaries and are the site of gas exchange in humans.

Again insufficient info to make the point.

ncea gas exchange essay

It is then drawn down the trachea which is supported by rings of cartilage, then splits into the two bronchi then into the bronchioles and into the alveoli, tiny air-sacs on the ends of the bronchioles. In my case I’d be drawing diagrams of various circulatory systems and possibly a heart as I’m doing animal transport systems.

The haemolymph is pumped towards the head using a many chambered dorsal aorta. Here is the link External gills receive oxygen passively from the surrounding water. The diagram is labelled incorrectly eg the gill filaments are labelled ‘lamellae’ and ‘gill rakers’ Quote: Gas exchange in insects involves air entering the tracheae through the spiracles openingspassing through the smaller tracheoles, and terminating in gws tissues.

The herbivores diet of mostly carbohydrates ezsay a low energy yield; this is ok for the herbivore however because of the low energy required and the accessibility of the diet.


Exhange include any other relevant info like arrows to show the direction of blood flow, features eg “septum divides heart into two pumps “keeping oxygenated and deoxygenated blood separate.

Thanks for all that help ST Try to run the sentences together so that you show u understand. Thanks ST5 Can I fix it and post my improvements on here? Gills This one is from a different angle so shows the gill rakers How does the two way flow of air used by mammals reduce this water loss. has

Therefore a very simple fold of membrane called the typhlosole, along the length of the intestine is sufficiently large enough to meet thier energy demands. An earthworm is small enough that the skin is a sufficient gas exchange organism; No Fish and mammals can be large because they have a circulatory system, and the blood capillaries are close to the gas exchange surface reducing distance for gases to diffuse through. essah

Gas Exchange – WGHS BAP Year 12

Because I have looked at the questions for the previous years, and and the first question is always the same just worded slightly differently. Like most of the gae 12 bio students, I’m wondering just how to answer all four papers in 3 hours The eexchange flow through the heart ensures that the blood has enough pressure to be circulated around the whole body and also to return to the heart. I am becoming increasingly confused when I read the responses the science teachers are giving in regards to peoples essays.

ncea gas exchange essay

Gas Exchange All living organisms respire. For the discussion part of the animal essay, do you only have to compare two animals?