Larger animals have a lower surface area to volume ratio. This means they need transport systems like our circulatory system and exchange surfaces like our lungs or fish gills.
Why do multicellular organisms need a transport system?
To increase their surface area to volume ratio
To move molecules internally when the rate of diffusion would be too slow
To provide additional exchange surfaces
Which path describes the movement of oxygenated blood?
Vena cava to right atrium to right ventricle
Pulmonary vein to left atrium to left ventricle
Right ventricle to pulmonary artery to lungs
Which of these statements is true of pulmonary circulation?
Blood is under high pressure
Blood is being delivered to the extremities of the body
Blood is collecting oxygen from the alveoli
Which type of blood cell does not have a nucleus?
Red blood cell
Which type of blood cell produces antibodies?
What are the tiny projections of the intestines called?
Which of these is not an adaptation of villi?
Good blood supply
Large surface area
What is the name of the substance that makes up 55% of blood?
Red blood cells
White blood cells
What are platelets?
Cells that fight pathogens
Small fragments of cells
What is the function of valves in the veins?
To keep the blood under high pressure
Prevent the back flow of blood
To pump the blood through the veins