biology Flashcards
Life processes
Movement, respiration, sensitivity, growth, reproduction, excretion, nutrition.
Movement in animals
Animals move using specialised structures (legs or wings) to help them survive.
Movement in plants
Plants cannot move their whole “body” like animals, but they move parts of themselves (like moving their leaves towards the sun).
Movement in nonliving things
Nonliving things can only move if they are pushed or pulled by something else.
Respiration
A chemical process that turns oxygen and glucose from food into energy.
Respiration is important because
All cells need energy, and living things are made up of cells.
Sensitivity
The ability of an organism to respond to changes in its external or internal environment.
Example of sensitivity
You sense that something is hot, it hurts when you touch it and you respond by quickly moving your hand away.
Proprioception
Knowing where your body parts are.
Electroreception
Sensing electrical stimuli.
Magnetoreception
Sensing magnetic stimuli.
Growth
The irreversible increase of an organism’s size over a given period.
Growth in animals
Most animals grow until they reach a certain size and then stop.
Growth in plants
Most plants continue growing throughout their entire lives.
Reproduction
The production of offspring via sexual or asexual reproduction.
Excretion
The removal of waste created by respiration and photosynthesis (so that it does not harm the organism).
Example of excretion
Carbon dioxide is a waste product of respiration, and too much carbon dioxide in your blood can kill you so it must be removed.
Nutrition
The process of taking in food and converting it into energy and other vital nutrients required for life.
Autotrophic nutrition
Photosynthesis
Heterotrophic nutrition
The organism which cannot produce food on their own and depend on other sources/organisms are called heterotrophs
Human full scientific name
Animalia, chordata, primates, hominidae, homo, (homo) sapiens
Why are humans classified as vertebrates?
They have a backbone, and are chordates.
Chordate
A species which has had a notochord at any stage of its life.
Chordate criteria
Gill slits during embryo stage. A post anal tail.
Why are humans classified as mammals?
They are homeothermic (constant body temperature), have a four chambered heart, have hair on the body, young develop within a uterus, females have glands that secrete milk.
Why are humans classified as primates?
They have forward facing eyes and fingernails instead of claws.
Hierarchy of structural organisation
Chemical level, cellular, tissue, organ, system, organism.
Cells
The basic structural and functional unit of living things.
Tissue
A group of cells with similar size and shape that function together for a common purpose.
4 basic types of tissue in the human body
Epithelium (skin), connective (bone/cartilage), muscle, nervous.
Organ
A structure comprised of two or more tissues that has a definite/specific shape, function and location.
Examples of organs
Heart, brain, liver, pancreas.
Organ system
A group of organs that function/work together i.e. coordinated for a common purpose.
Examples of organ systems
Skeletal, muscular, nervous, circulatory, digestive.
Homeostasis
The maintenance of a constant internal environment (keeping the conditions inside your body the same).
Examples of internal conditions that must be maintained at optimal levels
Blood glucose, blood water, body temperature, blood oxygen, temperature.
Optimal temperature for humans
37.5 degrees celsius. Because it is the optimal temperature for chemical reactions in our cells.
How does our body keep the internal temperature the same?
It must balance the heat lost and the heat gained. It does this by using behavioural and physiological methods.
Examples of behavioural methods
Change clothes, cold drink, reducing activity, seek a cool place.
Examples of physiological methods
Sweating, goosebumps, shivering.
Automatic control systems have
Three parts and messages that travel between them. Receptor > processing centre > effector
Receptor
Detects the change.
Processing centre (modulator/coordinator)
Processes information from the receptor and sends information to the effector.
Message
The message that is sent from the modulator to the effector.
Effector
The part of the body that carries out a response.
Stimulus
The change in the internal environment.
Components of a feedback loop
Stimulus, receptor, modulator, message, effector, response, feedback.
Negative feedback
When the output of a system acts to oppose changes to the input of a system. (A reaction that causes a decrease in function).