Module 2 - Organisation of living things Flashcards
Unicellular organisms
contain only one cell which can either be prokaryotic or eukaryotic. A single cell is responsible for all of its processes and functions. They are first life forms
Colonial organisms
made up of group of identical single-celled called a colony. Can survive independently but work together to survive
Multicellular organisms
multiply cells that work together, specialised cells that have a function. All have DNA and must communicate. Have a larger size so SA:V is smaller.
Advantages and disadvantages of these organisms
Multicellular - Advantage of increase in size without limitations. Disadvantage - Needs more food then others
Colonial - Advantage is they can manipulate their size. Disadvantage - Decreased freedom of movement
Unicellular - advantage is they reproduce quickly. Disadvantage - Shorter life span
Autotrophs and Heterotrophs
Autotrophs are organisms which make their own food and mostly do this by photosynthesis. Heterotrophs are organisms which are unable to do this and obtain nutrients by eating other organisms.
The root system
Another function that anchors the plants in soil and absorbs waters and minerals from it. Water moves into the roots by osmosis, mineral ions move by diffusion.
Shoot system - stem and leaves
The stem provides structural support and includes dermal, vascular and ground tissues.
Leaves provides photosynthesis and transportation (contains chloroplasts)
Gas exchange in pants
Is the leaf which allows carbon dioxide and oxygen to leave, gas exchange occurs mostly in the stomata and lenticels.
Gas exchange in animals
Animals possess different specialised structures to exchange gas.
Gas exchange in mammals -
Through alveoli
Transport systems in plants
Xylem tissue transports water and dissolves minerals which creates a respiration stream.
Phloem transports sugars and others produced by photosynthesis and move by active transport
Transport systems in animals
Circulatory system - pump sends fluid through tubes to the external environment. Arteries carry the blood away and have thick elastic walls.
Veins carry the blood back towards the heart (also contain valves)
Capillaries is where gas and chemical exchange happens