Unit 2 : Multi-cellular Organisms - Transport Systems Flashcards
What is the surface area to volume ratio for unicellular organisms ?
Relatively large
What is the surface area to volume ratio for multi-cellular organisms ?
Relatively small
What is the relationship between surface area to volume ratio ?
Inverse relationship
What are the 2 vessels involved in plants internal transport system ?
Xylem Vessel & Phloem Vessel
What does the xylem vessel transport ?
Transport water and minerals from the soil to the leaves for photosynthesis.
How does water travel up the plant ?
Via osmosis
Describe the structure of the xylem vessel ?
Dead hollow tube with rings of tough woody lignin for support.
What does the phloem vessel transport ?
Carries dissolved food from the leaves, up and down the plant.
What structures are within the phloem vessel ?
Companion cells control the phloem unit and provide energy. Food is transported in the cytoplasm strands through the sieve plates from cell to cell.
What is transpiration ?
Transpiration is the evaporation of water from the leaves.
What is the main site of photosynthesis in a plant ?
Leaves
What is the function of the wax cuticle ?
Waxy outer waterproof covering that reduces water loss by evaporation.
What is the function of the upper epidermis ?
Transparent thin layer of cell with no chloroplasts that allows light energy to pass through.
What is the function of the palisade mesophyll ?
Cells that contain lots of chloroplasts and are closely packed together. Most photosynthesis takes place in these cells.
What is the function of the spongy mesophyll ?
Round cells that contain some chloroplasts but have air spaces between cells to allow carbon dioxide to circulate and reach palisade cells.
What is the function of the vascular bundle ?
Contains xylem and phloem which supply all parts of the plant with water and dissolved food that is produced.
What is the function of the stomata ?
Tiny pores that allow carbon dioxide and water vapour to diffuse in and out of the leaf.
What is the function of the guard cells ?
Cells with chloroplasts on the lower epidermis that control the opening and closing of the stomata.
What does the animal circulatory transport system consist of ?
Heart, blood vessels , blood
What is the function of the red blood cells being disc-shaped and flexible ?
The cell can travel easily through narrow blood vessels.
What is the function of the red blood cell having a large surface area to volume ratio ?
Oxygen is kept close to the surface and can be released quickly.
What is the function of red blood cells having no nucleus ?
There is more room for haemoglobin and so more oxygen can be carried.