Unit 4 Part 3

Question 1

Motile organisms?

Answer 1

Organisms that have adaptations allowing movement within their habitat

Question 2

Sessile organisms?

Answer 2

Organisms that can’t move from place to place
- Are able to alter their body form in response to environmental stimuli

Question 3

Ex. of sessile organism?

Answer 3

Venus flytrap
- Dionaea muscipula
- In subtropical wetlands, N + S carolina
- Deficient in nitrogen

Question 4

How does a Venus fly trap obtain nutrition and nitrogen?

Answer 4

Obtains nutrition through photosynthesis and nitrogen through its prey

Question 5

Ex. of Motile organism?

Answer 5

Brown throated three toed sloth
- Bradypus variegatus
- Avg speed = 0.25 km/h-1
- are arboreal ( tree dwelling)
- Herbivorous
- Slow digestive ( month)
- Poop once a week
- Good swimmers

Question 6

Muscle fibers?

Answer 6

Cells found in each muscle ( thousands)
- Multinucleate

Question 7

Why are muscle fibers Multinucleate?

Answer 7

B/c each fibre represents several cells that have merged together

Question 8

Myofibrils?

Answer 8

Protein filaments found in each muscle fiber that run parallel to each other

Question 9

What are myofibrils placed along?

Answer 9

Contracting units called sarcomeres

Question 10

What happens when one sarcomere contracts?

Answer 10

B/c they are all attached to all sarcomeres in same muscle contract
- Resulting action makes the muscle fiber and entire muscle shorter`

Question 11

What proteins are in sarcomere?

Answer 11

Myosin and actin

Question 12

How do muscles shorten when sarcomeres contract?

Answer 12

When they contract , the actin filaments slide over the myosin fibres which results in each sarcomere shortening

Question 13

What is it called when muscles shorten due to sarcomere’s contacting?

Answer 13

The sliding filament theory

Question 14

Rigor mortis

Answer 14

Condition where bodies become v rigid a few hours after death

Question 15

How does rigor mortis happen?

Answer 15

The result of no new ATP being generated after death

Question 16

Tendons?

Answer 16

Connective tissues used in muscles to attach two bones

Question 17

Two types of bones in a muscle?

Answer 17

Origin and insertion
- Origin: Acts as an immovable anchor
- Insertion: Moves as a result of muscle contraction

Question 18

Antagonistic muscles?

Answer 18

Muscles that accomplish opposite movements b/c a muscle can only exert a force when it contracts so when a bone is moved it needs another muscle

Question 19

Titin?

Answer 19

An immense protein that has multiple folds that allow it to act as a spring
- It’s spring like action allows muscles to use a force to help w/ relaxation

Question 20

What creates a spring like tension in titin

Answer 20

When a sarcomeres shorten during a contraction and two sides of each sarcomere move towards centre
- Released when muscle relaxes

Question 21

Neuromuscular junctions?

Answer 21

Electrical impulses originating in your brain and terminating at synapses

Question 22

What does every movement made require?

Answer 22

Many neuromuscular junctions

Question 23

Motor neurons?

Answer 23

Neurons that carry messages from neuromuscular junctions

Question 24

Synapses?

Answer 24

Locations where the electrical activity of a neuron is converted into a chemical release at the terminal end

Question 25

What is the chemical released by synapses?

Answer 25

A neurotransmitter

Question 26

What type of synapse are neuromuscular junctions?

Answer 26

Type of synapses where a chemical message is sent into the muscle tissue to stimulate a contraction

Question 27

Each muscle is able to contract w/ varying intensity depending on..

Answer 27

How many of the total muscle fibers w/in the muscle receive a nervous system impulse to contract

Question 28

Motor unit?

Answer 28

A set number of muscle fibers that each single motor neurons controls

Question 29

How do motor units work?

Answer 29

If low intensity contraction is needed, a relatively low number of motor units is activated by the brain, vice versa

Question 30

Ratio of motor neurons to muscle fibers?

Answer 30

Varies from about 1;10 to 1;200

Question 31

What are vertebrate animals endoskeleton/ internal made out of?

Answer 31

Bones - Muscles are attached at various points outside the bones to allow movement

Question 32

What are arthropods's exoskeleton made out of?

Answer 32

A substance chitin - Attach muscles on inside of exoskeleton

Question 33

What do many individual bones and segments act as?

Answer 33

Levers

Question 34

Why do many individual bones and segments act as?

Answer 34

To maximize efficiency for a variety of movement

Question 35

What is a "lever"?

Answer 35

A rod that's a bone which is able to rotate about a fixed point known as a fulcrum, a joint

Question 36

Synovial joints?

Answer 36

When two bones need to move against each other and are notable for the wide range of motions they allow

Question 37

Where does the name ball-and-socket joint come from?

Answer 37

Comes from the head of a femur forming a ball that fits into a rounded socket in the pelvis bone

Question 38

Pelvis and femur function?

Answer 38

Bones forming the ball and socket joint of the hip

Question 39

Cartilage function?

Answer 39

A smooth protective connective tissues that lines the pelvis and femur w/in hip joint

Question 40

Synovial fluid function?

Answer 40

Lubricating fluid w/in hip that reduces friction

Question 41

Ligaments function?

Answer 41

Tough connective tissues that holds the bones of hip joint in place

Question 42

Tendons function?

Answer 42

Connective tissues that connects each muscle of hip joint to its appropriate bone

Question 43

Muscles function?

Answer 43

Muscle tissue that contracts and relaxes to allow movement of femur w/in socket of pelvis

Question 44

Goniometer?

Answer 44

An inexpensive device used by doctors to measure the range of motion of a joint

Question 45

What is range of motion?

Answer 45

The distance and direction that a joint can move, is usually measured in degrees

Question 46

What do the movements of ribs when you breathe in and out do?

Answer 46

Help expand the thoracic cavity when breathing and compresses thoracic cavity when out

Question 47

Position of internal intercostal muscles?

Answer 47

Under the external almost opposite to it. - Lies at an angle also using ribs as their origin and insertion points

Question 48

What happens when the external intercostal muscle contracts?

Answer 48

The expansion of the rib cage results in a stretching of the internal intercostal muscles

Question 49

Locomotion?

Answer 49

The ability to move from a place to a place

Question 50

Animals that are descended from ancestral species that once lived on land?

Answer 50

Marine mammals like dolphins, whales, seals

Question 51

Adaptations of dolphins?

Answer 51

1. Streamlined body - allows them to move through viscous water with ease and speed 2. Lost all body hair - reduces drag in water 3. Tail adapted to form fluke - allows up and down motion for propulsion 4. Lost all rear legs 5. Front limbs adapted to be flippers - used for steering 6. Have an airway called "blowhole" on top surface of head - to exchange air at periodic intervals w/out full body leaving water 7. Can seal blowhole tightly during breaths - so water doesn't enter airway 8. Can stay underwater for few mins 9. Still have mammalian characteristics like being endothermic, producing milk, Advanced two sided circulatory, and long term parental care for kids