B1(Cell Structure And Transport) Flashcards
What does the nucleus do
-Controls all the activities of the cell
-Contains genes on the chromosomes that carry the instructions for making proteins
What does the cytoplasm do
Where most of the chemical reactions for life take place
What does the cell membrane do
-Controls substances such as glucose and mineral ions into the cell
-Controls substances such as urea and hormones out of the cell
What does the mitochondria do
Where respiration takes place
What do ribosomes do
Protein synthesis
What does the cell wall do
Strengthens the plant cell
What does chloroplast do
Contain green substance called chlorophyll which absorbs light so the plant can make food by photosynthesis
What does the permanent vacuole do
Stores cell sap
What are Eukaryotic cells
They are cells which contain genetic material that is enclosed in a nucleus
What are prokaryotic cells
Cells which contain small rings of DNA called plasmids which are not enclosed in a nucleus
Examples of specialised animal cells
-Nerve cells
-Muscle cells
-Sperm cells
What are specialised cells
Cells that are adapted to do a specific function
Examples of specialised plant cells
-Root hair cells
-palisade cells
-Xylem cells
-Phloem cells
What are xylem cells
-dead cells that transport water and mineral ions from the roots to the shoots
-supports the cell
How do xylem cells transport water and mineral ions
-lignin builds up in spirals in the cell walls
-the cells die and form long hollow tubes
-this allows water and ions to move easily through them
What are phloem cells
-transports food made by photosynthesis around the body of the plant
How do phloem cells transport food around the plant
-The cell walls break down to form special sieve plates
-This allows water carrying dissolved food to move freely up and down tubes to where it is needed
-Phloem cells are supported by companion cells that keep them alive
-the mitochondria of the companion cells transfer the energy needed to move dissolved food up and down the plant to the phloem
What is the formula for magnification
What is transpiration
the loss of water vapour from plant leaves by evaporation of water at the surfaces of the mesophyll cells
What are the factors that affect transpiration
What is translocation
The transport of sucrose and amino acids in phloem, from regions of production to regions of storage or use
What is a transpiration stream
Water moving through the xylem vessels
