types of transport systems Flashcards
why are transport systems required
multicellular organisms cannot rely on passive transport for supply of nutrients and gas and removal of waste
what are the requirements of transport systems
system of vessels
fluid transport medium
driving mechanism
Outline the two types of circulatory systems
Closed: occurs in vertebrates with blood and enclosed blood vessels that carry both oxygen and blood
Open: occurs in invertebrates with haemolymph and open vessels that bathe tissues carrying only oxygen. Haemolymph collects in sinuses before flowing into heart.
What are the main components of blood
red blood cells: contain haemoglobin to carry oxygen
White blood cells: defence against disease
Platelets: clot blood to control bleeds
Plasma: carries dissolved substances such as nitrogenous waste and products of digestion like glucose and amino acids
other: ions such as salt, calcium and magnesium to balance pH
Outline the structure of xylem and phloem
xylem: continuous hollow tube
phloem: sieve tube cells with pores (connected cytoplasm) and companion cells which act as mediums between the sieve tube and other cells
