UNIT 4 - B 3.3 - Muscles and Motility

Question 1

What are motile organisms?

Answer 1

organisms that have adaptations allowing movement within their habitat

Question 2

What are sessile organisms?

Answer 2

organisms that cannot move from place to place, only their body can move in response to environmental stimuli

Question 3

What is an example of a sessile organism?

Answer 3

venus flytrap

Question 4

How do venus flytraps trap and digest insects?

Answer 4

it waits for an insect to enter its paired leaves and trigger hairs within, then the leaves close around the prey and the internal portion of the leaves secretes enzymes to digest the insect

Question 5

What is an example of a motile organism?

Answer 5

brown-throated three-toed sloth

Question 6

What adaptations make movement on the ground almost impossible for sloths?

Answer 6

they have three long toes on each foot and a specific bone structure and musculature to be adpated to hanging from branches and moving using a pulling motion

Question 7

How are mammals able to move?

Answer 7

they have muscles attached to bones

Question 8

What kind of organism is a barnacle in terms of motion?

Answer 8

sessile

Question 9

what is tropism?

Answer 9

the movement of an organism (usually a plant) towards an external stimulus

Question 10

How do amoeba move?

Answer 10

using their cytoskeleton to move their plasma membrane

Question 11

What are muscle fibres?

Answer 11

the cells that compose muscle

Question 12

Why are muscle fibres multinucleate?

Answer 12

because each fibre represents several cells that have merged together

Question 13

What are myofibrils?

Answer 13

protein filaments which each muscle fibre is composed of

Question 14

What are sarcomeres?

Answer 14

contracting units that are sequentially placed along each myofibril

Question 15

Why is it that when one sarcomere contracts, all the sarcromeres in the same muscle also contract?

Answer 15

because all the sarcomeres are attached to one another end to end

Question 16

What does the resulting action of sarcomeres contracting do?

Answer 16

it makes the muscle fibre and entire muscle shorter

Question 17

What is the result of alternating fibres of the proteins myosin and actin?

Answer 17

the striations of skeletal muscle

Question 18

What happens with myosin and actin when a sarcomere contracts?

Answer 18

the myosin remain stationary and the two sides of the actin move towards the centre of the sarcomere

Question 19

How is myosin and actin able to interact when a sarcomere contracts?

Answer 19

with myosin’s movable head that interacts with actin using ATP in specific pathways

Question 20

What is the sliding filament theory?

Answer 20

the model of muscle contraction - when sarcomeres contract, actin filaments slide over the myosin fibres resulting in each sarcomere shortening

Question 21

What are the dark areas of sarcomeres a result of?

Answer 21

the presence of both actin and myosin in those areas

Question 22

How do muscles attach to bones?

Answer 22

using connective tissues called tendons

Question 23

What is the bone that acts as an immovable anchor called?

Answer 23

the origin

Question 24

What is the bone that moves as a result of muscle contraction called?

Answer 24

the insertion

Question 25

Why is it that if a bone is moved with one muscle, another muscle is required to move the bone the opposite way?

Answer 25

because a muscle can only exert a force when it contracts

Question 26

What does it mean for two muscles to be antagonistic to each other?

Answer 26

they accomplish opposite movements

Question 27

What is titin?

Answer 27

a protein with multiple folds that allow it to act like a spring

Question 28

What creates the spring-like tension in titin that is released when the muscle relaxes?

Answer 28

the two sides of each sarcomere moving towards the centre when sarcomeres are shortened during contraction

Question 29

What does titin do for myosin fibres and muscle fibres?

Answer 29

it holds myosin fibres in place and prevents muscle fibres from overstretching

Question 30

What are neuromuscular junctions?

Answer 30

a type of synapse where a chemical message is sent into the muscle tissue to stimulate a contraction

Question 31

What do motor neurons carry?

Answer 31

neurons that carry the chemical message of neuromuscluar junctions

Question 32

What does a muscles contraction intensity depend on?

Answer 32

how many of the total muscle fibres within the muscle receive a nervous system impulse to contract

Question 33

What is a motor unit?

Answer 33

a set of muscle fibres controled by single motor neurons

Question 34

What does the brain do if a low intensity contraction is needed?

Answer 34

activates a low number of motor units

Question 35

What results in different movements of vertebrate animals?

Answer 35

relative differences in bone length and muscle attachments

Question 36

What are exoskeletons made of?

Answer 36

chitin

Question 37

Where are the muscle attachment points for arthropods (like insects) with exoskeletons?

Answer 37

on the inside of the hollow skeleton

Question 38

What do many individual bones and segments of skeletons act as to maximize efficiency for different movements?

Answer 38

levers

Question 39

What is a fulcrum in terms of bones?

Answer 39

a joint

Question 40

What does the lever action of bones and joints allow for muscles?

Answer 40

allows them to exert a lower force to accomplish any one movement

Question 41

How are arthropods capable of a large range of motion?

Answer 41

by maximizing leverage

Question 42

Where do synovial joints occur?

Answer 42

in the body where two bones need to move against each other

Question 43

What are synovial joints notable for?

Answer 43

the wide range of motion they allow

Question 44

What are examples of synovial joints?

Answer 44

joints at elbow, knee, shoulder, hips

Question 45

What is an example of a ball-and-socket joint?

Answer 45

the head of a fermur fits into a rounded socket in the pelvis bone

Question 46

What does cartilage help avoid?

Answer 46

bone on bone contact

Question 47

What do ligaments do?

Answer 47

hild bones in place while allowing a range of motion

Question 48

What do the pelvis and femur do in the pelvis structure?

Answer 48

they form the ball-and-socket joint of the hip

Question 49

What does cartilage do for the pelvis structure?

Answer 49

as a smooth protective tissue, it lines botht he pelvis and femur within the hip joint

Question 50

What does the synovial fluid do for the pelvis structure?

Answer 50

reduces friction

Question 51

What do tendons do for the pelvis structure?

Answer 51

as a connective tissue, it connects each of the muscles of the hip joint to its appropriate bones

Question 52

What does a goniometer do?

Answer 52

measure the range of motion of a joint

Question 53

What is range of motion for joints?

Answer 53

the distance and direction it can move

Question 54

What are the intercostal muscles between the ribs an example of?

Answer 54

an antoagoistic pair

Question 55

What do intercostal muscles use ribs as?

Answer 55

their origin and insertion points

Question 56

What do both the external intercostal muscles and internal intercostal muscles use as the fulcrum point?

Answer 56

the attachment of the ribs to the vertebrae

Question 57

What happens when the external intercostal muscles contract?

Answer 57

the rib cage is pulled upwards and out

Question 58

What do the internal intercostal muscles do when they contract?

Answer 58

move the ribcage down and inwards

Question 59

How do external/internal intercostal muscles store potential energy that will be used for the next contraction of the opposite muscle?

Answer 59

Through the stretching of the opposite muscle and the titin in each sarcomere of that muscle layer, creating the potential energy

Question 60

what are reasons for locomotion amung animals?

Answer 60

foraging for food, escape danger, searching for mate, migration, dispersal

Question 61

What involves a honey bee foraging for food?

Answer 61

flying from flower to flower to collect nectar and pollen

Question 62

What involves a flying fish escaping danger?

Answer 62

swimming fast and extending their long pectoral fins to glide over the water

Question 63

What involves a loggerhead sea turtle searching for a mate?

Answer 63

both males and females swim back to the beach where they were hatched to mate and lay eggs

Question 64

What involves arctic tern migrating?

Answer 64

migrating from arctic breeding grounds to the antarctic region and back each year to take advantage of available food

Question 65

What involves a hoary bat dispersing?

Answer 65

north american populations have established permanent colonies on the Hawaiin Islands

Question 66

What are adaptations of dolphins to be able to live in the ocean?

Answer 66

streamlined body, lack of body hair, tail that forms a fluke, no rear legs, front limbs became flippers, blowhole for air, sealing the blowhole between breaths, can stay underwater for several minutes, retained mammalian characteristics

Question 67

What do dolphins' streamlined bodies allow?

Answer 67

movement through the water with ease and speed

Question 68

What does the lack of body hair allow for dolphins?

Answer 68

reduced drag through the water

Question 69

What does the fluke of dolphins allow?

Answer 69

an up and down motion for propulsion

Question 70

what are the flippers of dolphins primarily used for?

Answer 70

stearing

Question 71

What do dolphins' blowhole allow?

Answer 71

exhange of air with minimal of the body leaving the water

Question 72

What does sealing the dolphins blowhole allow?

Answer 72

water to not enter the airway

Question 73

What can dolphins do since they can stay underwater for minutes without breathing?

Answer 73

they can make deep dives

Question 74

What mammalian characteristics have dolphins retained?

Answer 74

being endothermic, producing milk for young, having a two-sided circulatory system, long-term parental care of young