Biology 1 : Topic 2

Front 1

Homeostasis

Back 1

How living things keep their body's internal environment stable and constant; self-regulating

Front 2

Examples of homeostasis

Back 2

1) regulating body water content

2) body temperature

Front 3

Osmoregulation

Back 3

The process by which the body regulates water content;

Front 4

How osmoregulation works

Back 4

1) signals to the brain send info about the water content of the blood

2) brain sends hormones to the kidneys to regulate the amount of water they remove in urine

Front 5

Stimuli

Back 5

Triggers for the response

Front 6

What temp must the body be at

Back 6

37*c

Front 7

Thermoregulation

Back 7

How the body regulates it's temp

Front 8

Responses to increased body temp

Back 8

1) increased blood flow thought the blood vessels in the skin, making you look flushed. More blood causes more heat to be lost from the skins surface

2) sweat is produced so heat from the body evaporates the water in sweat, transferring heat away from the skin

3) body hair lies flat which prevents air from trapped. Air is a poor conductor of heat so the absence of an air layer allows more heat to escape

Front 9

Response to decreased body temp

Back 9

1) less blood flow through the the blood vessels so less heat is lost from the skins surface

2) shivering which means tiny muscles under the skin are contracting and relaxing very quickly so the muscles release heat

3) body hairs stand on end which traps a layer of air which insulates the body

Front 10

What is body temp monitored by

Back 10

Thermoregulatory centre; hypothalamus

Front 11

How the thermoregulatory centre works

Back 11

Detects temp of blood; processes info; sends nerve impulses to sweat glands and hair erector muscles

Front 12

What do do Erector muscles

Back 12

Control shivering and blood flow through the skin

Front 13

Feedback

Back 13

Info about changes in self-regulating mechanism that allows it to adjust, maintaining a constant internal environment

Front 14

Negative feedback

Back 14

Away from normal back to normal

Front 15

Vasoconstriction

Back 15

Narrowing of blood vessels in the skin; blood flow is reduced; less heat is lost; body temp rises

Front 16

Vasodilation

Back 16

Widening of blood vessels; blood flow increased; more heat is lost; body temp falls

Front 17

Muscles relax

Back 17

Blood vessels widen

Front 18

Hormones

Back 18

Chemicals produced by endocrine glands; circulate in the blood; affect different tissues and organs; help to regulate the body's activities; maintain homeostasis

Front 19

Hormones the pancreas produces

Back 19

Insulin and glucagon which help to regulate the blood glucose levels

Front 20

What is the blood glucose level normally at

Back 20

90mg per 100cm^3 of blood

Front 21

When does blood glucose rise

Back 21

Following a meal as digested food is absorbed from the intestine into the blood stream

Front 22

When does blood glucose level fall

Back 22

During exercise as vigorously contracting muscles use extra glucose for energy

Front 23

What does the pancreas monitor

Back 23

The pancreas monitors the level of blood glucose and triggers a response to return the levels to normal if they change

Front 24

Role of insulin

Back 24

Released from the pancreas when blood glucose is high. It helps convert glucose into another type of carbohydrate called glycogen, which is stored in liver and muscle tissue

Front 25

Role of insulin

Back 25

Released from the pancreas when blood glucose is high. It helps convert glucose into another type of carbohydrate called glycogen, which is stored in liver and muscle tissue

Front 26

Glucagon

Back 26

Released from the pancreas when blood glucose is low and promotes the conversion of glycogen into glucose, which is released into the bloodstream

Front 27

Hormones

Back 27

Are specific to their target tissues so they can only bind to the membrane of their target tissues cells and not to any other tissues

Front 28

Hormones

Back 28

Are specific to their target tissues so they can only bind to the membrane of their target tissues cells and not to any other tissues

Front 29

Diabetes

Back 29

A condition in which the body cannot properly regulate its blood glucose level so it becomes dangerously high which increases the risk of serious health problems

Front 30

Why does type 1 diabetes happen

Back 30

The pancreas does not produce enough to insulin

Front 31

Why does type 1 diabetes happen

Back 31

The pancreas does not produce enough to insulin

Front 32

Why does type 2 diabetes happen

Back 32

The pancreas still produce insulin but the target tissues (liver and muscles) become insensitive to it

Front 33

Why does type 1 diabetes happen

Back 33

The pancreas does not produce enough to insulin

Front 34

Why does type 2 diabetes happen

Back 34

The pancreas still produce insulin but the target tissues (liver and muscles) become insensitive to it

Front 35

Which diabetes happen in younger people typically

Back 35

Type 1

Front 36

Why does type 1 diabetes happen

Back 36

The pancreas does not produce enough to insulin

Front 37

Why does type 2 diabetes happen

Back 37

The pancreas still produce insulin but the target tissues (liver and muscles) become insensitive to it

Front 38

Which diabetes happen in younger people typically

Back 38

Type 1

Front 39

Which diabetes typically happens in older people

Back 39

Type 2

Front 40

Why does type 1 diabetes happen

Back 40

The pancreas does not produce enough to insulin

Front 41

Why does type 2 diabetes happen

Back 41

The pancreas still produce insulin but the target tissues (liver and muscles) become insensitive to it

Front 42

Which diabetes happen in younger people typically

Back 42

Type 1

Front 43

Which diabetes typically happens in older people

Back 43

Type 2

Front 44

Treatment for type 1

Back 44

Daily injections of insulin into the body's subcutaneous fat (such as thigh) to reduce blood glucose levels

Front 45

What factors depend on the amount of insulin required for type 1 diabetes

Back 45

1) diet

2) exercise

Front 46

What factors depend on the amount of insulin required for type 1 diabetes

Back 46

1) diet

2) exercise

Front 47

How can people with type 2 diabetes regulate their blood glucose level

Back 47

1) careful eating

2) exercise

3) losing weight

4) drugs

Front 48

What is type 1 diabetes a result of

Back 48

1) auto-immune disease = when a persons immune system destroys the pancreatic cells that produce insulin

2) genetic disorder = a mutation of the gene encoding the production of insulin

Front 49

Correlation

Back 49

There is a strong correlation between obesity and the development of type 2 diabetes

Front 50

BMI

Back 50

Body mass index

Front 51

BMI

Back 51

Body mass index

Front 52

How do you calculate BMI

Back 52

Mass (kg) / height (m)^2

Front 53

Plant hormones

Back 53

Responsible for tropism e.g auxin

Front 54

Phototropism

Back 54

Response of plants to the stimulus of light

Front 55

Phototropism

Back 55

Response of plants to the stimulus of light

Front 56

Gravitropism

Back 56

Response of plants to the stimulus of gravity

Front 57

Positive phototropism

Back 57

Bending towards the light

Front 58

Positive phototropism

Back 58

Bending towards the light

Front 59

Auxins

Back 59

Responsible for regulating shoot growth; discovered by Frits went; he investigated the development of cereal seedlings and carried out many experiments to investigate the effects the auxin on shoot growth in response to light

Front 60

In shoots

Back 60

Auxins are more concentrated on side where light is least intense; cells here grow more quickly; shoot grows towards the brightest light

Front 61

In shoots

Back 61

Auxins are more concentrated on side where light is least intense; cells here grow more quickly; shoot grows towards the brightest light

Front 62

In roots

Back 62

Where concentration of auxins is high; cells of the tissues grow more slowly; more concentrated on the underside so grow more slowly; causes roots to grow downwards

Front 63

Tropism

Back 63

growth in response to a stimulus. Plants grow towards sources of water and light, which they need to survive and grow.

Front 64

Tropism

Back 64

growth in response to a stimulus. Plants grow towards sources of water and light, which they need to survive and grow.

Front 65

Positive tropism

Back 65

Grow towards the stimulus

Front 66

Negative tropism

Back 66

Grow away from it

Front 67

Cuttings

Back 67

Copies of plants made by dipping the end in rooting powder which contains plant hormones that encourages cut stems to develop roots

Front 68

Fruit ripening

Back 68

Can be picked unripe and transported or stored in warehouses; plant hormone called ethene gas is released into the air around the fruit to ripen it just before it is delivered to shops

Front 69

Herbicide

Back 69

Contain plant hormones that stimulate the growth of plants stems. As the rate of root growth does not keep pace with the stem, the roots are not able to absorb enough water to support the growing plant and it dies; only affect the weeds as they are broad-leaved and absorb more herbicide than narrow-leaved crop plants

Front 70

Seedless fruit

Back 70

Produced by smearing the plants female sex organs with auxin paste to stimulate the development of the fruit. But the egg cells within the female sex organs have not been fertilised so seeds are not produced

Front 71

Different types of receptor detect different types of stimuli

Back 71

1) photoreceptors = detect light

2) thermoreceptors = detect changes in body temp (skin)

- can be found all over the body and others are concentrated in sense organs

Front 72

Retina

Back 72

Photoreceptors from a layer of cells in the eye

Front 73

Sensitivity to touch depends on

Back 73

1) force bearing down on the area of skin

2) number of touch receptors in the area

E.g fingertips are very sensitive to touch as they contain many touch receptors

Front 74

Neurone

Back 74

Nerve cell that contains of cell body with thin fibres stretching from it. The fibres carry electrical impulses

Front 75

Nervous system

Back 75

Bundles of neurones from nerves

Front 76

Central nervous system (CNS)

Back 76

Consists of brain and spinal cord

Front 77

Peripheral nervous system

Back 77

Consists of the nerves connecting the sense organs with the central nervous system

Front 78

Sensory neurones

Back 78

Send impulses from receptors in the sense organs to the CNS

Front 79

Motor neurones

Back 79

Send impulses from the CNS to muscles and glands

Front 80

Similarities between sensory and motor neurones

Back 80

1) both have a cell body and fine branches called dendrites

2) fibres that carries electrical impulses from the cell body to the dendrites is called the axon

Front 81

Differences between sensory and motor neurones

Back 81

1) motor neurones have very long axons whereas sensory neurones have short ones

2) fibre that carries electrical impulses to the cell body is called dendron

Front 82

Receptors in the sensory neurone fibres

Back 82

Detect stimuli which convert them into electrical impulses (nerve impulses) and send them along neurones to muscles and glands

Front 83

Involuntary responses

Back 83

Things we do without thinking; automatic; protect our body from damage

Front 84

Involuntary responses

Back 84

Things we do without thinking; automatic; protect our body from damage

Front 85

Voluntary responses

Back 85

Those we think about

Front 86

Parts of the CNS that coordinate different responses

Back 86

1) brain coordinates voluntary responses

2) spinal cord coordinates involuntary responses

Front 87

Stimuli

Back 87

Changes in the environment e.g stepping on a pin

Front 88

Stimuli and responses

Back 88

Stimuli; receptor; sensory neurone; CNS; motor neurone; effector; response

Front 89

Nerve impulses are sent to the effectors

Back 89

Muscles are effectors and the impulses cause them to contract; receptors are linked to effectors by a chain of neurones; the fibres at the end of one neurone are separated from the beginning of the next neurone by tiny gaps called synapses

Front 90

Neurotransmitters

Back 90

Chemical messengers that carry information across the synapse

Front 91

Myelin sheath

Back 91

Fatter substance surrounding dendrons and axons that speed up the nerve impulses along neurones

Front 92

Involuntary behaviour

Back 92

Is known as a reflex response; automatic and usually fast; protect body from damage; brought about by a chain of nerves called a reflex arc

Front 93

Reflex arc

Back 93

Receptor; sensory neurone; relay neurone; motor neurone; effector; synapses between each neurone