B3 Form and Function : Organisms

Question 1

double circulatory system

Answer 1

To go around the body once, blood has to pass through the heart twice.

Question 2

antagonistic muscles

Answer 2

Opposing pairs of muscles that work in opposite directions or have opposing effects.

Question 3

thoracic cavity

Answer 3

The volume or space within your chest.

Question 4

total lung capacity

Answer 4

The total volume of air in your lungs after inhaling the maximum possible volume of air.

Question 5

forced vital capacity

Answer 5

The volume of air you can exhale with maxiumum effort after inhaling the maximum possible volume of air.

Question 6

residual volume

Answer 6

The volume of air remaining in the lungs that cannot be exhaled even after maximum expiration.

Question 7

tidal volume

Answer 7

The volume of air that moves into and out of your lungs with every normal breath.

Question 8

inspiratory reserve

Answer 8

The extra volume of air that can be inhaled with maximum effort beyond the volume of air inhaled in a normal inspiration.

Question 9

expiratory reserve

Answer 9

The extra volume of air that can be exhaled with maximum effort beyond the volume of air exhaled after a normal exhalation.

Question 10

transpiration

Answer 10

Transpiration is the loss of water vapour from plant leaves. Water vapour is lost by evaporation at the surface of the mesophyll cells; this water vapour then diffuses through the stomata and out of the plant.

Question 11

allosteric

Answer 11

A site other than the main binding site.

Question 12

multinucleate

Answer 12

A cell containing more than one nucleus.

Question 13

myofibrils

Answer 13

Thread-like structures found in muscle fibres composed of repeating sarcomeres.

Question 14

myosin

Answer 14

A fibrous contractile protein, forms the thick protein filaments in a sarcomere.

Question 15

actin

Answer 15

A fibrous contractile protein, forms the thin protein filaments in a sarcomere.

Question 16

Z discs

Answer 16

A region that organises and anchors the actin, as well as defining the boundaries of a sarcomere.

Question 17

M line

Answer 17

A region in the centre of a sarcomere that organises and anchors the myosin.

Question 18

I bands

Answer 18

The region on a sarcomere where only actin is present.

Question 19

A band

Answer 19

The region on a sarcomere where myosin is present.

Question 20

H band

Answer 20

The region in the middle of the sarcomere containing only myosin.

Question 21

Tropomyosin

Answer 21

A protein subunit that runs alongside actin, blocking the myosin binding sites when the sarcomere is relaxed.

Question 22

troponin

Answer 22

A protein subunit that, when calcium binds to it, undergoes a conformational change, moving tropomyosin away from the myosin binding sites on actin.

Question 23

sarcoplasm reticulum

Answer 23

A specialised endoplasmic reticulum that surrounds a myofibril and contains and releases calcium ions.

Question 24

cross-bridge

Answer 24

A structure formed when a myosin head binds to a myosin binding site on actin.

Question 25

power stroke

Answer 25

A movement of the myosin head that pulls the actin filament towards the centre of the sarcomere.

Question 26

titin

Question 27

skeletal muscle unit

Answer 27

A muscle fibre and the motor neuron that innervates it.

Question 28

ligaments

Answer 28

Strong, flexible bands of connective tissue that connect bones to bones.

Question 29

tendons

Answer 29

Fibrous structures that attach muscle to bones.

Question 30

flexion

Answer 30

Bending of a joint that decreases the angle between the bones involved.

Question 31

extention

Answer 31

Straightening of a joint that increases the angle between the bones involved.

Question 32

abduction

Answer 32

Movement of a bone away from the midline of the body.

Question 33

adduction

Answer 33

Movement of a bone towards the midline of the body.

Question 34

rotation

Answer 34

Movement of a bone around its axis.

Question 35

circumduction

Answer 35

Circular movement of a limb that involves flexion, abduction, extension and adduction in sequence.

Question 36

external intercostal muscles

Answer 36

A group of muscles between the ribs that contract during inspiration and relax during expiration.

Question 37

internal intercostal muscles

Answer 37

A group of muscles between the ribs that relax during inspiration and contract during expiration.