Unit 4 Part 1

Question 1

What happens to the surface area to volume ratio as an organism gets larger?

Answer 1

It changes - decreases

Question 2

What limits and organism’s ability to take in and release substance?

Answer 2

Its outer surface area layer

Question 3

What can rely on direct exchange of respiratory gasses with their environment?

Answer 3

Only the smallest organisms

Question 4

What do non small organisms rely on to get oxygen to internal tissues and take carbon DI away?

Answer 4

On anatomical and physiological adaptations

Question 5

Where are specialized tissues found?

Answer 5

• Skin of some organisms
• Gills of many aquatic organisms
• Lungs of some large terrestrial organisms

Question 6

What are gas exchange surfaces characterized by?

Answer 6

1. Being thin to keep diffusion distances shorter - Usually one cell layer
2. Being moist to encourage gas diffusion
3. Having large surface area for max diffusion
4. Being permeable to respiratory gasses - Oxygen + Carbon DI

Question 7

What must concentration gradients be maintained for?

Answer 7

For oxygen to diffuse into blood and carbon DI out of blood

Question 8

What is exothermic?

Answer 8

Cold blooded

Question 9

What species are exothermic?

Answer 9

All animals that use gills

Question 10

What is endothermic?

Answer 10

Warm blooded

Question 11

What do capillaries do?

Answer 11

They are the only blood vessels that permit the exchange of substances

Question 12

How thick are capillaries?

Answer 12

Only one cell thick

Question 13

What’s the difference between the levels of blood that leaves body tissues vs levels of blood before it reaches the active body tissue?

Answer 13

Blood that leaves body tissues has a higher concentration of carbon DI + lower concentration of oxygen compared to levels before the blood reached the active body tissues

Question 14

Where has blood that is first circulated to the gills been?

Answer 14

W/in capillaries of the muscles and other body tissue

Question 15

Concentration of oxygen and carbon DI in lung capillaries

Answer 15

Oxygen: Lower than the air inspired
Carbon DI: Higher than the air inspired

Question 16

What are the two events that must occur to keep concentration gradients in place?

Answer 16

1. Water/air must be continuously passed over/refressed (ventilated) in the gills/ lungs
2. There must be a continuous blood flow to blood vessels in both the body tissues and tissues of gills or lungs

Question 17

What are the alveoli?

Answer 17

Microscopic spheres
- Tiny air sacs

Question 18

What are the alveolus?

Answer 18

singular alveoli
- A terminal end of one of the branches of bronchioles

Question 19

What did alveolus start off as?

Answer 19

The trachea

Question 20

What is a surfactant?

Answer 20

Thin phospholipid and protein film that lines the inner surface of each alveolus

Question 21

What does the surfactant do?

Answer 21

Reduces the surface tension of the moist inner surface + helps prevent each alveolus from collapsing each time air is expired

Question 22

What are the bronchioles?

Answer 22

Small tubes that connect to the subdivided millions of spherical alveoli

Question 23

What does the spherical shape of the alveoli provide?

Answer 23

A vast surface area for the diffusion of oxygen and carbon DI

Question 24

What type of tissue makes up our lungs?

Answer 24

Passive

Question 25

What are the muscles surrounding the lungs?

Answer 25

Diaphragm, muscles for the abdomen, and external and internal intercostal muscles

Question 26

What does Boyle's law state?

Answer 26

" An increase in volume will lead to a decrease in pressure, and vice versa"

Question 27

Where are the lungs located?

Answer 27

Inside the thorax/ thoracic cavity - which only has one opening through the trachea

Question 28

What is the diaphragm?

Answer 28

Large, Dome-shaped muscle that forms the "floor" of thorax

Question 29

What happens when a diaphragm contracts?

Answer 29

It flattens the dome shape + increases volume of thorax

Question 30

What is a spirometer?

Answer 30

A device used to measure lung volume

Question 31

What are the volumes that a spirometer can measure?

Answer 31

- Tidal volume - Inspiratory reserve volume - Expiratory reserve volume - Vital capacity

Question 32

What is tidal volume?

Answer 32

Volume of air that's breathed in or out during a normal cycle

Question 33

What is Inspiratory reserve volume?

Answer 33

Max volume of air that a person can breathe in

Question 34

What is Expiratory reserve volume?

Answer 34

Max volume of air a person can breathe out

Question 35

What is vital capacity?

Answer 35

Sum of Inspiratory reserve volume, tidal, and expiratory

Question 36

Adaptations of a leaf

Answer 36

- Waxy cuticle - Upper + Lower epidermis - Palisade mesophyll - Spongy mesophyll - Veins - Stomata

Question 37

Waxy cuticle adaptation

Answer 37

Covers epidermis cells and reduces evaporation

Question 38

Epidermis cells adaptations

Answer 38

Found on the upper and lower surface of leaves that secrete a waxy cuticle and are transparent allowing lights into mesophyll cells where photosynthesis happens - Guard cells forming stomata are on lower epidermis

Question 39

Palisade mesophyll adaptations

Answer 39

Densely packed region of cylindrical cell in upper portion of leaf

Question 40

Spongy mesophyll adapation

Answer 40

Loose packed cells located below the palisade layer and above stomata - Few chloroplasts and air spaces around palisade increase surface area for gas exchange

Question 41

Air space adaptation

Answer 41

Facilitates diffusion of gasses between surrounding atmospheres and mesophyll cells

Question 42

Stomata adaptation

Answer 42

Pores that allow gasses to enter and leave cell - More common on lower epidermis of leaves and are opened and closed by guard cells

Question 43

Veins adapation

Answer 43

Encloses fluid transport tube; xylem and phloem are located centrally w/in a leaf to give access to all cell layers

Question 44

What does water do in xylem?

Answer 44

Moves up from root stems to the leaf

Question 45

What does water do in Phloem?

Answer 45

Water and dissolved sugar are distributed to other parts of plants

Question 46

What is transpiration?

Answer 46

The evaporation of water through open stomata

Question 47

How can number of stomata be expressed?

Answer 47

mm^-2 or μm^-2

Question 48

What are erythrocytes?

Answer 48

Blood cells - A plasma membrane surrounding cytoplasm filled w/ Haemoglobin molecules

Question 49

What are haemoglobin molecules capable of?

Answer 49

Of reversibly binding to both oxygen and carbon DI molecules

Question 50

Which atom is binding when haemoglobin is binding to oxygen

Answer 50

the iron atom

Question 51

What is cooperative binding?

Answer 51

When any oxygen molecule is bonded to a haemoglobin increasing its attraction for more oxygen

Question 52

What is allostery?

Answer 52

Binding of carbon DI to polypeptide chains of haemoglobin and resulting change in haemoglobins affinity for oxygen

Question 53

What is the allosteric site?

Answer 53

Area of each polypeptide when carbon DI binds

Question 54

What is bohr shift?

Answer 54

The binding of carbon DI to haemoglobin resulting in an increase in the release of oxygen molecules and decrease for affinity of oxygen

Question 55

What is haemoglobin job?

Answer 55

Uses cooperative binding of oxygen molecules to ensure sufficient oxygen is brought to respiring tissue

Question 56

features of erythrocytes

Answer 56

- Biconcave shape - Each contain 300M haemoglobin molecules - No nucleus = More space to carry haemoglobin

Question 57

Structure if type 1 pnuemocytes?

Answer 57

Extremely thin (0.1-0.2 μm thick) and have a large surface area

Question 58

What is the function of Type II pneumocytes?

Answer 58

Secrete pulmonary surfactant and can differentiate into Type I pneumocytes

Question 59

Air inspired into alveoli?

Answer 59

Oxygen: higher concentration carbon do: Lower concentration