Exchange and Transport systems Flashcards
Explain the difference between exchange organs and mass transport systems of the single cell organisms and multicellular organisms
Single cell organisms can diffuse directly into or out of the cell across the surface membrane so the diffusion rate is quick because of the small distances the substance has to travel
multi cellular organisms diffuse across the outer membrane is too slow because some cells are deep within the body so there’s a larger distance and larger animals have small surface area to volume ratio
What do multicellular organisms ease instead of diffusion
Rather than straightforward diffusion to absorb and excrete substances multi cellular organisms need specialised exchange organs
What is mass transport
When multicellular organisms need an efficient system to carry substances to and from their individual cells for example the circulatory system
Explain how a body size affects heat exchange
Heat loss of an Organism depends on its surface area if an Organism has a large surface area to volume ratio then heat loss easily achieved that means smaller organisms need a relatively high metabolic rate to generate enough heat to stay warm whereas larger organisms have a small surface area to volume ratio so it makes heat loss harder metabolic rates are then slower
How does body shape affect heat exchange
Animals of any size with a compact shape have a small surface area to volume ratio which minimises heat loss from their surface whereas animals with a less compact shape such as a bit of gangly or sticky outside bits have larger surface area to their volume this increases heat loss from their surface
What are the adaptations for heat exchange
Whether an animal is compact or not depends on the temperature of its environment so the animal’s body shape is adapted to suit its environment
what impact does iron deficient plants have on growth rates
1-less thylakoid membranes
2-reduced surface area
3-less light is the absorbed
4-slower photosynthesis
