8. Exchange and transport and animals. Flashcards
what substances need to be transported in and out of organisms
oxygen, carbon dioxide, water, dissolved, food, molecules, mineral irons, urea
where is oxygen exchanged?
alveoli in the lungs
where is water exchanged
nephrons in the kidneys
where is carbon dioxide exchanged?
alveoli
where are dissolved food molecules exchanged
small intestines
where are mineral irons exchanged?
small intestines
where is urea exchanged?
nephrons in the kidneys
why do multicellular organisms, need exchange surfaces and a transport system
The surface area: volume ratio is too small to be able to rely on diffusion
What is the name of the process by which gases exchange between air in the lungs and blood in the capillaries?
diffusion
how are alveoli adapted for gas exchange
they have a large surface area, they have thin walls, they have blood vessels close to them
name, the four main parts of blood
Red blood cells, white blood cells, plasma and platelets
what is another name for red blood cells?
erythrocytes
what is the function of red blood cells?
The transport oxygen around the body
how are red blood cells adapted to their function?
they contain haemoglobin which carries oxygen, they have a biconcave shape and therefore a large surface area, they don’t have a nucleus so this so has more space for the haemoglobin to transport more oxygen
name, two types of white blood cells
lymphocytes and phagocytes
which system in the body white blood cells a part of?
the immune system
what is the job of the immune system?
to attack pathogens in the body
what do you phagocyte to do?
The surround pathogens and destroy them
what do you lymphocytes do?
they produce chemical antibodies that attack pathogens and destroy them
describe plasma
It’s as a liquid part of the blood
what is the function of plasma?
it carries the blood cells through the blood vessels that contain and dissolves substances
give two examples of substances that may dissolve in plasma
carbon dioxide and glucose
what are platelets?
fragments of larger cells, they don’t have a nucleus