Transport Flashcards
why do multicellular organisms need transport systems
-diffusion to all cells would be too slow to meet the organism’s needs, so transport systems are required
role of the xylem
transport water and mineral ions from roots to other parts of the plant
role of phloem
transport sucrose and amino acids from where they are produced or stored to where they are needed
how are root hair cell adapted
-large surface area due to long projection for efficient absorption of water by osmosis and minerals via active transport
steps for root hair cells to take in minerals
-active transport using energy from mitochondria
steps for root hair cells to take up water
-osmosis
-water concentration of cell cytoplasm reduced due to presence of mineral ions
-water moves into the root hair cell by osmosis
route of water through the plant
-osmosis into the root hair cell, through the root cortex and into xylem vessels
-carried up to leaves entering the mesophyll cells by (transpiration?)
what does blood consist of
red blood cells, white blood cells, platelets and plasma
approx breakdown of blood by %
plasma - 55%
45% RBC
<1% WBC and platelets
structure of red blood cell
biconcave discs containing no nucleus to maximise capacity for haemoglobin
structure of white blood cells
-large cells containing large nucleus
platelets structure
-fragments of cells
plasma structure
clear, straw-coloured aqueous solution
what does plasma contain
CO2: from respiring cells to lungs
Digested food and mineral ions: from small intestine to requiring cells around the body
Urea: (liver?)to kidneys
Hormones - from endocrine organs to target tissues
Heat energy: to cooler parts/skin where heat can be lost
how are red blood cells to their function of carrying oxygen to respiring cells
-contains haemoglobin, protein that binds to oxygen to form oxyhaemoglobin
-no nucleus to allow more space for haemoglobin to be packed in
-biconcave disc shape gives large surface area to volume ratio to maximise diffusion of oxygen in and out
types of white blood cells
phagocytes
lymphocytes
structure of phagocyte
-cell membrane
-cytoplasm
-lobed nucleus
white blood cells against infection (5)
1 ingest / engulf / surround / phagocytosis / eq;
2 enzymes;
3 digest / breakdown / eq;
4 lymphocytes;
5 antibodies / antitoxins;
6 specific / eq;
7 antigen:
8 memory / memory cell / eq
- phagocytes (engulf) pathogens
- they secrete digestive (enzymes) to (break down) pathogens
- (lymphocytes) produce (antibodies) which bind to (specific) (antigens) of pathogen
- (memory cells) are left behind in the blood after the infection
describe how a phagocyte defends against pathogens
-(phagocytosis)
-cell surface membrane detect chemicals produced by pathogenic cells
-(engulf/pseudopodia) the pathogenic cell when encountered until the pathogen is inside the phagocyte/phagosome
-release (digestive enzymes/lysosome) to break down pathogen
-(vesicles/phagosome fuse with pathogen)
-(products of digestion expelled) from the vesicle and phagocyte
-non-specific response
how do lymphocytes defend against pathogens
-produce (antibodies)
-(specific) to the (antigens) on the surface of the pathogen
-antibodies (bind to and kill) pathogens
-antibodies also mark pathogens for other white blood cells
-make memory cells
what are vaccinations used for
-induce immunity to infectious diseases
-reduces cases of certain diseases or even eradicates them
what do vaccines contain
-harmless pathogens