2019 Bio paper Flashcards

1
Q

The investigations were carried out in daylight.
The air bubble would not move if the investigations were done in the dark.
Explain why.

A

no photosynthesis
(so) stomata closed (as no
carbon dioxide needed)
(so) no transpiration

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

Give one advantage of using an electron microscope compared with using a
light microscope.

A

Greater magnification and higher reolving power

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

Explain how villi are adapted for efficient absorption of sugar molecules.

A

have (many) microvilli
* (to) increase surface area
* wall of villus only one cell thick or is thin
* capillaries are close to surface
* (so) short pathway
* good blood supply
* (to) transport food molecules away or to the body
* (and) maintain a diffusion gradient
* cells have many mitochondria
* (where) respiration takes place
* (where) energy is transferred
* (as) active transport requires energy
* energy is needed to absorb sugar / food / molecules

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

People are encouraged to control their body mass with diet and exercise.
Describe how the balance between the mass of food eaten and the amount of
exercise a person does controls body mass.

A

increased energy intake
if more food eaten
* if exercise more, more
energy is transferred /
released
* if more energy is taken in
than is transferred body
mass increases
or
if less energy is taken in
than is transferred body
mass decreases
* if energy intake = energy
transferred body mass
stays the same

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

0 5 . 1 How can oxygen production be used to show the rate of photosynthesis?

A

measure the volume of oxygen
produced in a given time
or
when more oxygen is produced
in a given time the rate of
photosynthesis is faster

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

The light intensity you gave in Question 05.3 may not give the farmer maximum profit.
Explain why.

A

there is a cost for heating the
greenhouse
there is a cost for increasing the
carbon dioxide in the
atmosphere (of the greenhouse)
(therefore) the additional costs
might exceed the (additional)
sale price / profit

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

0 5 . 5 Explain the results when the light intensity was 0 lux.

A

when there is no light there is no
photosynthesis
(so) no oxygen is produced
(but) respiration happens (all the
time) and oxygen is used
(therefore) the net / overall
oxygen production is negative

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

The lamp gets warm when it is on. This causes the temperature of the water box
to increase.
0 1 . 3 Explain how an increase in temperature would affect the results of this investigation.

A

bubbles (of gas) would be
produced faster
(because) enzymes work faster

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

0 1 . 4 Suggest one way the investigation could be improved so the temperature of the water

A

use an LED (lamp)
* place a tank / beaker of water
between the lamp and tube /
pondweed
* put the tube in a beaker of
water
* put the tube in a
(thermostatically controlled)
water bath
* place a piece of glass
between the lamp and tube /
pondweed

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

Suggest two improvements to the investigation so the results would be more valid.
Do not refer to controlling the temperature of the water phot exp

A

measure the volume of gas
produced
* allow the pondweed time to
equilibrate
* repeat and calculate a mean
or
repeat and remove anomalies
* control the concentration of
carbon dioxide (in the water)
* use the same bulb / lamp

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