Biology

Question 1

Multicellular Organisms

Answer 1

an organism that is composed of many cells. Most plants and animals are multicellular.

Question 2

Homeostasis

Answer 2

the maintenance of a relatively constant internal physiological environment of the body or part of the body (e.g. blood glucose level, pH, body temperature) in varying external conditions

Question 3

Stimulus response model

Answer 3

a system in which any changes or variations (stimuli) in the internal environment are detected (by receptors); if a response is required, this is communicated to effectors to bring about some type of change or correction so the conditions can be brought back to normal

Question 4

Negative feedback

Answer 4

a response that reduces the original stimulus

Question 5

Glucose

Answer 5

simple carbohydrate and the simplest form of sugar

Question 6

Pancreas

Answer 6

large gland in the body that produces and secretes the hormone insulin and an important digestive fluid containing enzymes

Question 7

Insulin

Answer 7

hormone that removes glucose from the blood and stores it as glycogen in the liver and muscles

Question 8

Glycogen

Answer 8

The main storage carbohydrate in animals, converted from glucose by the liver and stored in the liver and muscle tissue

Question 9

Positive feedback

Answer 9

a reaction in which the response is in the same direction as the stimulus—for example, during childbirth the onset of contractions activates the release of the hormone oxytocin, which stimulates further contractions

Question 10

Oxytocin

Answer 10

hormone secreted from the pituitary gland that assists in the formation of bonds between mothers and their babies, and perhaps between people in close relationships

Question 11

Nervous system

Answer 11

the system of nerves and nerve centres in an animal in which messages are sent as an electrical and then a chemical impulse. It comprises the central nervous system and the peripheral nervous system.

Question 12

Endocrine systems

Answer 12

the body system of glands that produce and secrete hormones into the bloodstream in order to regulate processes in various organs

Question 13

Signalling molecules

Answer 13

a chemical involved in transmitting information between cells

Question 14

Central nervous system

Answer 14

the part of the nervous system composed of the brain and spinal cord

Question 15

Peripheral nervous system

Answer 15

made up of sensory and motor neurons. It connects the central nervous system to the rest of the body, and detects and responds to change.

Question 16

Sensory Neurons

Answer 16

a nerve cell in the sense organs. It detects change in the environment and sends a message to the central nervous system.

Question 17

Motor Neurons

Answer 17

the nerve cell that causes an organ, such as a muscle or gland, to respond to a stimulus

Question 18

Neurotransmitters

Answer 18

chemical released from the axon terminals into the synapse between your nerve cells (neurons) during a nerve impulse

Question 19

Endocrine glands

Answer 19

organs that produce hormones. Endocrine glands release their hormones into the bloodstream for transport to target organs

Question 20

Hormones

Answer 20

chemical substances produced by glands and circulated in the blood. Hormones have specific effects in the body.

Question 21

Thermorgulation

Answer 21

The control of body temperature

Question 22

Thermostat

Answer 22

device that establishes and maintains a desired temperature automatically

Question 23

Sense Organs

Answer 23

a specialised structure that detects stimuli (such as light, sound, touch, taste and smell) in your environment

Question 24

Stimuli

Answer 24

changes in the environment that can be detected and responded to

Question 25

Thermoreceptors

Answer 25

special cells located in your skin, part of your brain and body core that are sensitive to temperature

Question 26

Mechanoreceptors

Answer 26

special cells within the skin, inner ear and skeletal muscles that are sensitive to touch, pressure and motion, enabling you to balance, hear and sense pressure and movement

Question 27

Chemoreceptors

Answer 27

special cells within a sense organ (especially the nose and tastebuds) that are sensitive to particular chemicals, giving you the sensations of smell and taste

Question 28

Photoreceptors

Answer 28

a receptor cell located in your eye that is stimulated by light, converting it to electrical energy that is sent to the brain, giving you the sensation of light

Question 29

Pain receptors

Answer 29

special cells located throughout the body (except the brain) that send nerve signals to the brain and spinal cord in the presence of damaged or potentially damaged cells, resulting in the sensation of pain

Question 30

Hot thermoreceptors

Answer 30

a type of receptor in your skin that can detect an increase in skin temperature above 37.5°C (normal body temperature)

Question 31

Cold thermoreceptors

Answer 31

a type of receptor in your skin that can detect a decrease in skin temperature below 35.8 °C

Question 32

Olfactory nerve

Answer 32

nerve that sends signals to the brain from the chemoreceptors in the nose

Question 33

Pupil

Answer 33

a hole through which light enters the eye

Question 34

Iris

Answer 34

coloured part of the eye that opens and closes the pupil to control the amount of light that enters the eye

Question 35

Reflex action

Answer 35

a quick response to a stimulus. Reflex actions do not involve thought.

Question 36

Cornea

Answer 36

the curved, clear outer covering of your eye

Question 37

Lens

Answer 37

transparent curved object that bends light towards or away from a point called the focus. The eye has a jelly-like lens.

Question 38

Retina

Answer 38

curved surface at the back of the eye. It is lined with sight receptors.

Question 39

Short sightedness

Answer 39

the condition of not being able to see clearly things that are far away

Question 40

Long sightedness

Answer 40

the condition of not being able to see clearly things that are close

Question 41

Optic Nerve

Answer 41

large nerve that sends signals to the brain from the sight receptors in the retina

Question 42

Rods

Answer 42

sensory receptors in the retina that respond to low levels of light and allow you to see in black and white in dim light

Question 43

Cones

Answer 43

sensory receptors in the retina that respond to red, green or blue light. Cones are mainly in the central part of the retina.

Question 44

Colour blindness

Answer 44

an inherited condition, more common in males, in which a deficiency of one or more of the different types of cones may mean that you find it difficult to see a particular colour or combinations of colours

Question 45

Ear canal

Answer 45

the tube that leads from the outside of the ear to the eardrum

Question 46

Ear drum

Answer 46

a thin piece of stretched skin inside the ear that vibrates when sound waves reach it

Question 47

Ossicles

Answer 47

a set of three tiny bones that send vibrations from the eardrum to the inner ear. They also make the vibrations larger.

Question 48

Middle ear

Answer 48

the section of the ear between your eardrum and the inner ear, containing the ossicles

Question 49

Cochlea

Answer 49

the snail-shaped part of the inner ear. It is lined with tiny hairs that are vibrated by sound and stimulate the hearing receptors.

Question 50

Auditory nerve

Answer 50

a large nerve that sends signals to the brain from the hearing receptors in the cochlea

Question 51

Tongue

Answer 51

the sense organ responsible for taste

Question 52

Taste buds

Answer 52

nerve endings located in your tongue that contain receptors sensitive to sweet, salty, bitter, sour and savoury chemicals, allowing you to experience taste

Question 53

Papila

Answer 53

bumps on your tongue that are thought to contain tastebuds

Question 54

Dendrites

Answer 54

Structure that relays information towards the cell body of a neuron

Question 55

Cognition

Answer 55

another name for thinking or mental activity

Question 56

Emotions

Answer 56

feelings, such as happiness, sadness and anger, that are interpreted by the brain

Question 57

Regulating

Answer 57

the process by which the brain detects and responds to the body’s internal and external environments

Question 58

Hindbrain

Answer 58

a continuation of the spinal cord

Question 59

Pons

Answer 59

part of the brain involved in regulating sleep, arousal and breathing, and coordinating some muscle movements

Question 60

Medulla obglonata

Answer 60

a part of the brain developed from the posterior portion of the hindbrain and continuing with the spinal cord; see also brain stem

Question 61

Reticular formation

Answer 61

a network of neurons that opens and closes to increase or decrease the amount of information that flows into and out of the brain

Question 62

Forebrain

Answer 62

consists of the cerebrum, cerebral cortex, thalamus and hypothalamus

Question 63

Cerebral cortex

Answer 63

the outer, deeply folded surface of the cerebrum

Question 64

Thalamus

Answer 64

part of the brain through which all sensory information from the outside (except smell) passes before going to other parts of the brain for further processing

Question 65

Hypothalamus

Answer 65

monitors internal systems and controls the release of hormones to maintain the normal body state (homeostasis)

Question 66

Hippocampus

Answer 66

part of the brain with a key role in consolidating learning, comparing new information with previous experience, and converting information from working memory to long-term storage

Question 67

Brain stem

Answer 67

the part of the brain connected to the spinal cord, responsible for breathing, heartbeat and digestion. Sometimes called the medulla.

Question 68

Cerebellum

Answer 68

the part of the brain that controls balance and muscle action

Question 69

Cerebrum

Answer 69

the largest part of the brain (about 90 per cent of total brain volume), responsible for higher order thinking, controlling speech, conscious thought and voluntary actions. It is made up of the frontal, temporal, parietal and occipital lobes.

Question 70

Cerebral hemisphere

Answer 70

the left and right halves of the brain

Question 71

Corpus callosum

Answer 71

a bridge of nerve fibres through which the two cerebral hemispheres communicate

Question 72

Synaethesia

Answer 72

a condition in which a sensation is produced in one physical sense when a stimulus is applied to another; affected people may associate letters with a flavour, numbers with a gender or sounds with colour