Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

OCR Biology A for AS and A-Level > Module 3 > Flashcards

Module 3 Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What are the common features of an effective exchange surface?

A

High surface area
Thin layers
Good blood supply/counter current (if applicable)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which specialised cells can be found lining the trachea?

A

Ciliated epithelial cells (columnar) and Goblet cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the process of inspiration

A

Diaphragm and external intercostal muscles contract, increasing the volume of the lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the process of expiration

A

The muscles relax, which is passive. In a heavy expiration internal intercostal muscles contract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define vital capacity

A

The total volume minus the residual volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define tidal volume

A

The volume of air breathed in or out during a normal breath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define inspiratory reserve volume

A

Volume of maximum possible inspiration (excluding the tidal volume)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define expiratory reserve volume

A

Volume of air left in the lungs after the maximum possible expiration (excluding the tidal volume)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do you calculate Ventilation Rate?

A

Tidal volume multiplied by breathing rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the anatomy involved in insect ventilation

A

Spiracles (with sphincters) connected to tracheae and then into tracheoles - which are bathed in tracheal fluid. If the insect wishes to exchange more gas, it withdraws the fluid to allow more oxygen to dissolve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which direction does the water flow over gill lamellae?

A

From the efferent vessel toward the afferent vessel (in the opposite direction of blood flow)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the bony flap called that goes over the gills?

A

Operculum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does a fish force water over its gills?

A

Fill the buccal cavity with water, close the mouth and contract the cavity as it opens the operculum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is ram ventilation?

A

Constantly moving with an open mouth and operculum in order the induce gas exchange. Conducted by sharks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Name two adaptations that gills have to make gas exchange efficient

A

Tips of adjacent gill filaments overlap

Water flows in the opposite direction to the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the name of the body cavity which open circulatory system pump blood into?

A

Haemocoel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is insect blood called, and what properties does it have?

A

Haemolymph, it carries only food and waste, and is often green or yellow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the main difference between an open and closed circulatory system?

A

Closed systems are quicker and carry blood at higher pressures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe the composition of arteries

A

Small lumen, and a thicker elastic and collagen layer (to withstand recoil), some also have smooth muscle to regulate vasodilation and vasoconstriction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe the composition of veins

A

Larger lumen, and lots of collagen, not much smooth muscle, and some have no elastin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How do veins prevent backflow?

A

Some have valves and some run near large, active muscles to help squeeze blood through them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Describe the basic composition of the blood

A

About 55% plasma, and the rest is made up of platelets, erythrocytes and leucocytes etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe the pressure changes at the arterial end of a capillary

A

Hydrostatic Pressure is higher than oncotic pressure, which forces the net flow of the fluid out of the capillary

24
Q

Describe the pressure changes at the venous end of a capillary

A

Hydrostatic Pressure is lower than the oncotic pressure which forces the net flow of the fluid into the capillary

25
Q

Describe the structure of Haemoglobin

A

Made of 4 subunits (2 alpha and 2 beta) that each carry one oxygen molecule. One erythrocyte can contain 300 million molecules of Haemoglobin

26
Q

What is meant by the Positive Cooperativity of Haemoglobin?

A

It changes shape each time oxygen associates to a subunit to increase its affinity for the next molecule

27
Q

What is the Bohr Shift?

A

At higher partial pressures of carbon dioxide, haemoglobin dissociates its oxygen more readily and the oxygen dissociation curve moves to the right

28
Q

Which globular proteins in the body have a higher affinity for oxygen than Haemoglobin?

A

Myoglobin and Foetal-Haemoglobin

29
Q

What is the enzyme called that catalyses the conversion of carbon dioxide and water into carbonic acid?

A

Carbonic Anhydrase

30
Q

What is the Chloride shift?

A

Movement of chloride ions into a molecule of haemoglobin to compensate for the charge gradient caused by the Hydrogen-carbonate ions moving out

31
Q

Which side of the heart houses the tricuspid atrio-ventricular valve?

A

The (patient’s) right side

32
Q

What is the name of the tissue that conducts electrical impulse down the septum of the heart, to the apex?

A

Purkyne fibres

33
Q

Which ventricle wall is thicker, and why?

A

The left, it has to pump blood (at pressure) around the entire body

34
Q

What causes the ‘lub-dub’ heart sounds?

A

The closure of the atrio-ventricular and semilunar valves respectively

35
Q

What special feature does cardiac muscle have?

A

It is myogenic - it holds its own natural rhythm

36
Q

What is bradycardia?

A

Heart rate too slow

37
Q

Why do organisms need transport systems?

A

To meet metabolic demands
Because of their large size
Because of their small surface area to volume ratio

38
Q

In cross sections and transections of plant tissue, where can the xylem be seen?

A

In the vascular bundle, toward the centre or top, next to the phloem

39
Q

Describe the immediate structure of Xylem and which tissues surround it

A

Xylem is a mostly-dead tissue made of lignin, it is surrounded by parenchyma and tannin - which is a bitter chemical which deters herbivory. It contains scars where end-cells have fused also

40
Q

What connects the phloem and companion cells?

A

Plasmodesmata

41
Q

What is the Apoplast pathway?

A

Movement of water through the cell walls of cells

42
Q

What is the Symplast pathway?

A

Movement of water through the cytosol and plasmodesmata of cells

43
Q

What is the role of the Casparian strip?

A

Waterproof layer that blocks the Apoplast route, forcing the water to take the Symplast route, filtering out any toxins

44
Q

What evidence is there to support that endodermal cells actively pump minerals into the xylem, in order to change the water potential and draw water in?

A 
Metabolic poisons (like cyanide) halt movement
Root pressure increases alongside temperature
Guttation (cutting xylem) shows sap leaking out
45
Q

What is Transpiration?

A

Net water loss in a plant, from the opening of stomata and evaporation

46
Q

What is the Transpiration Stream?

A

The path of the flow of water through a plant, from the roots up to the stomata

47
Q

What evidence is there to support the Cohesion-Tension Theory

A

High rates of transpiration shrink tree-diameters

Broken Xylem vessels draw air in, not water out

48
Q

Which plant cell primarily controls transpiration?

A

Stomata

49
Q

What factors affect transpiration?

A 
Light intensity
Relative humidity
Temperature
Air-movement
Soil-hydration
50
Q

Name two common assimilates of translocation

A

Sucrose and amino acids

51
Q

How is sucrose loaded into the phloem?

A

Co-transport on hydrogen ions. ATP pumps hydrogen out and it ‘diffuses’ back in with sucrose attached

52
Q

What evidence is there that supports the translocation theory?

A

Advances in microscopy
Translocation stops in mitochondria are poisoned
The flow is faster that diffusion alone could be
Pressure in the phloem forces sap out of stylets

53
Q

What adaptions do Xerophytes have?

A 
Think waxy cuticle
Less or sunken stomata 
Small leaf surface area
Curled or Hairy leaves
Succulents - store water in special parenchyma
54
Q

What adaptations do hydrophytes have?

A

Thin (or no) waxy cuticle
Stomata on upper surfaces
Reduced structural support
Wide, flat leaves
Air sacs to help leaves float
Aerenchyma, parenchyma with apoptic air spaces
Pneumatophores, root nodules that grow into the air to aid gas exchange

55
Q

What are lenticels?

A

Special sites on the stem or root that act like stomata

OCR Biology A for AS and A-Level (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions