Transport/Circulatory System - SS2 Biology Past Questions and Answers - page 2

Right ventricle

Left ventricle

Aorta

Coronary artery

Unicellular organisms rely on diffusion for the transport of nutrients and waste products within their bodies. As single-celled organisms, they have a high surface-to-volume ratio, allowing for efficient exchange of substances through their cell membrane via diffusion.

Simple multicellular organisms have an open circulatory system, where hemolymph is pumped by a heart-like structure and directly bathes the tissues. Mammals, on the other hand, have a closed circulatory system with a four-chambered heart and specialized blood vessels that allow for efficient oxygen and nutrient delivery to body tissues.

Plants have a complex vascular system composed of xylem and phloem. Xylem transports water and minerals from the roots to the rest of the plant, while phloem carries sugars produced during photosynthesis to different parts of the plant, including storage organs and growing tissues.

Human blood consists of plasma, red blood cells, white blood cells, and platelets. Plasma carries nutrients, hormones, and waste products. Red blood cells transport oxygen, while white blood cells play a vital role in the immune response. Platelets aid in blood clotting to prevent excessive bleeding.

The heart is a muscular organ responsible for pumping blood. It consists of four chambers: two atria and two ventricles. Blood vessels, including arteries, veins, and capillaries, form a network that transports blood throughout the body. Arteries carry oxygenated blood away from the heart, veins bring deoxygenated blood back to the heart, and capillaries allow for the exchange of nutrients, gases, and waste products between blood and tissues.