Topic 2 - Structure and functions in living organisms Flashcards
What are the levels of organisation in organisms?
organelle, cell, tissue, organ, system
What structures are included in a cell?
nucleus, cytoplasm, cell membrane, cell wall, mitochondria, chloroplasts, ribosomes, vacuole
What is the function of the nucleus?
controls cell activities and contains genetic material
What is the function of the mitochondria?
produces energy through respiration
What is the primary function of ribosomes?
synthesize proteins
List the chemical elements present in carbohydrates.
- carbon
- hydrogen
- oxygen
What is the basic unit of starch?
simple sugars
What is the basic unit of proteins?
amino acids
What is the basic unit of lipids?
fatty acids and glycerol
What role do enzymes play in biological systems?
act as biological catalysts in metabolic reactions
True or False: Enzyme function can be affected by temperature changes.
True
What is the process by which substances move into and out of cells?
diffusion, osmosis, active transport
What factors affect the rate of movement of substances into and out of cells?
- surface area to volume ratio
- distance
- temperature
- concentration gradient
What is photosynthesis?
the process of converting light energy to chemical energy
What is the word equation for photosynthesis?
carbon dioxide + water → glucose + oxygen
What mineral ions do plants require for growth?
- magnesium ions for chlorophyll
- nitrate ions for amino acids
What components should a balanced diet include?
- carbohydrates
- proteins
- lipids
- vitamins
- minerals
- water
- dietary fibre
What is the structure of the human alimentary canal?
- mouth
- oesophagus
- stomach
- small intestine
- large intestine
- pancreas
What is peristalsis?
the movement of food through the gut
What role does bile play in digestion?
- neutralises stomach acid
- emulsifies lipids
What are the differences between aerobic and anaerobic respiration?
aerobic uses oxygen; anaerobic does not
What is the structure of the thorax?
- ribs
- intercostal muscles
- diaphragm
- trachea
- bronchi
- bronchioles
- alveoli
- pleural membranes
True or False: The immune system uses white blood cells to respond to disease.
True
What is the role of the phloem in plants?
transports sucrose and amino acids
What is the function of the xylem?
transports water and mineral ions from the roots
What adaptations do red blood cells have for oxygen transport?
- biconcave shape
- absence of nucleus
- presence of haemoglobin
What is homeostasis?
the maintenance of a constant internal environment
What are the components of a reflex arc?
- stimulus
- receptor
- effector
What are the roles of neurotransmitters?
transmit signals across synapses
What is the role of auxin in plants?
controls phototropic responses
What hormones are involved in human regulation?
- adrenaline
- insulin
- testosterone
- progesterone
- oestrogen
What happens during vasodilation?
blood vessels widen to increase blood flow
