Muscle

Question 1

motile species

Answer 1

Motile: Organism that have adaptations allowing movement within their habitat. E.g. Brown-throated three-toed sloth

Question 2

sessile species

Answer 2

Sessile: Organisms cannot move from place to place but are still able to alter their body form in response to environmental stimuli. E.g. Venus flytrap

Question 3

3 types of major muscles in the body

Answer 3

Cardiac muscles
Smooth muscles
Skeletal muscles

Question 4

Skeletal muscles

Answer 4

Skeletal muscle is attached to ___bone_____ and causes ____movement____ of animal bodies. It consists of large ____multinucleated__________ cells called muscle fibers.There are also ____mitochondria__________ between the myofibrils.

Question 5

level of organisation

Answer 5

muscle fibres –> myrofibrils –> microfilaments –> sarcomere

Question 6

what is around myofibrils

Answer 6

Around the myofibrils is a specialized type of endoplasmic reticulum – the _______sarcoplasmic reticulum_______________.

Question 7

do skeletal muscles require electrical impulses from the brain

Answer 7

Skeletal muscles are _______voluntary muscles_______________ that requires electrical impulse from the brain.
Electrical impulse are sent from the brain through the ______motor neuron________________ to the ______neuromuscular junction________________.

Question 8

what is a motor unit

Answer 8

Each motor neuron has a set number of muscle fibers that it controls called a ______motor unit ________________.

Question 9

what happens during contraction of striated muscle

Answer 9

Contraction of striated muscle makes the light bands ___narrower_________ and the sarcomeres ___shorter_________.

Question 10

what is sarcomere

Answer 10

A ____sacromere________ is a subunit of a myofibril.
Between two ____Z lines________ is one unit of sarcomere.
Light bands are represented by _______thin actin filaments_______________ only, which are attached to either end of the Z lines.
Dark band represent the region containing _______thick myosin filament_______________, which contains heads that form ____cross-bridges__________________ by binding to the actin.

Question 11

Muscle Contraction – Control

Answer 11

1) Sarcoplasmic reticulum releases ____calcium_______ ions.
2) Calcium ions binds to ____troponin_______
3) Troponin ____changes shape_______, pulling the ______tropomyosin_____ away from the ______actin-myosin binding site________________ which exposes it.
4) The myosin head then binds to the actin forming the ____actin-myosin cross-bridge__________________

Question 12

Muscle Contraction - Cross-bridge cycle

Answer 12

1) myosin heads are activated by splitting ATP. This causes a change in the position of the heads

2) Myosin heads are attracted to and attach to exposed binding sites of actin to form cross-bridges. Inorganic phosphate is released

3) As myosin forms cross-bridge ADP is released and the myosin bends due to loss of energy. The bending is towards the centre of the sarcomere and the actin is moved inwards

4) Myosin binds to ATP and this allows detachment of the myosin heads from the actin attachment sites

The contraction cycle continues if ATP is available and Ca2+ levels in the sarcoplasm are high

Question 13

Myosin Detachment

Answer 13

ATP is needed to ___break off___________ the actin-myosin cross-bridge.
Corpses body is stiffed in a state called _____rigor mortis_________, because they don’t ___respire_______ to produce energy to unlock the actin-myosin bridge.
After rigor mortis, body muscle start to break down due to ____decay process________.

Question 14

Muscles relaxation

Answer 14

Muscles usually relaxed by the contraction of the _______antagonistic muscle_________________
A protein ____titin___ also helps with relaxation.
Titin is a protein with____multiple folds____________ allow it to act as a __spring_____.
When sarcomere shorten during contraction, Z-lines moved towards the center and creates a _____spring-like tension________________ in titin.
The tension is __released_____ during relaxation and allow sarcomere to contract again.
Titin also holds __myosin_____ fibers in place and prevents ___overstretching___________.

Question 15

Role of skeletons

Answer 15

Animals have ____ internal_______ skeletons made up of ____bones_______
Arthropods have _____external______ skeletons made up of ___chitin________
Multiple bones and segments of skeletons act as ___levers________
Levers ________maximize the force______________exerted by a muscles and changes the ___direction________ of the movement.
Fixed point that allows the bone to rotate is known as ______fulcrum_____, e.g. joint.

During a movement:
One bone act as an immovable anchor (_____origin______)
The other bone moves as a result of the muscle contraction (___insertion________)

Question 16

Synovial joints – Ball and socket joint

Answer 16

Allows a rotation of 360°.

Question 17

Synovial joints – Hinge joint

Answer 17

Allows a plane movement of 180°.

Question 18

Cartilage

Answer 18

A smooth connective tissue that covers _______the ends of the bones___________ to reduce friction.

Question 19

Synovial fluid

Answer 19

_____Lubricate_______ the joint to reduce friction

Question 20

Tendons

Answer 20

Nonelastic tissue, attaches _____muscles_____ to bones

Question 21

Ligaments

Answer 21

Sightly elastic tissue, attaches ___bones_______ to bones, shock absorption

Question 22

antagonistic muscles

Answer 22

Antagonistic muscles: a pair of muscles that _____work oppositely_____________ to bring out movement.
Flexor muscles: Contract when the joints are moving to a _____smaller angle__________
Extensor muscle: Contract when the joints are moving to a _____larger angle__________
Example 1: Biceps and Triceps (Biceps are flexor, whereas triceps are extensor.)
Example 2: Internal (flexor muscle) and External (extensor muscle) intercostal muscles
Radius connects to thumb

Question 23

need for locomotion

Answer 23

foraging for food
escape danger
searching for mate
migration
dispersal

Question 24

foraging for food

Answer 24

honey bees

flying from flower to flower to collect nectar and pollen

Question 25

escape danger

Answer 25

flying fish

escaping predators by swimming fast and extending their very long pectoral fins to glide over the water

Question 26

searching for mate

Answer 26

loggerhead sea turtle

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

Question 27

migration

Answer 27

artic tern

migrating from their artic breeding grounds to the Antarctic region and back each year, to take advantage of available food

Question 28

dispersal

Answer 28

hoary bat

north American population have established permanent colonies on the Hawaiian Islands

Question 29

swimming adaptations

Answer 29

Streamlined body
No body hair
Tail formed a fluke
Lost of rear legs
From limbs formed flippers
Airway called blowhole on the surface of the head
Seal blowhole between breaths
Retain mammalian characteristics

Question 30

Streamlined body

Answer 30

Reduce friction and allow animal to move through the viscous water with greater speed

Question 31

No body hair

Answer 31

Reduce friction

Question 32

Tail formed a fluke

Answer 32

Allows an up-and down motion for propulsion

Question 33

Lost of rear legs

Answer 33

Movement provided by the fluke

Question 34

From limbs formed flippers

Answer 34

Used for steering

Question 35

Airway called blowhole on the surface of the head

Answer 35

Minimize the body leaving the water during ventilation

Question 36

Seal blowhole between breaths

Answer 36

Water cannot enter the airway

Question 37

Retain mammalian characteristics

Answer 37

Endothermic, Producing milk, double circulatory system