Quiz for EEI SAC

Question 1

why are there different types of plants

Answer 1

they are categorised into how they fix carbon into glucose

Question 2

how do C3 plants carry out the Calvin Cycle

Answer 2

These plants carry out the original Calvin Cycle, using Rubisco, and are prone to photorespiration

Question 3

what are optimal conditions for C3 plants

Answer 3

moist and cool conditions

Question 4

how do C3 plants use RuBisco

Answer 4

use the Rubisco enzyme to fix inorganic carbon dioxide from the air and it enters the Calvin cycle joined to a carrier molecule (RuBP)

Question 5

where does the Calvin Cycle take place in C3 plants

Answer 5

in the stroma of the leaf mesophyll cells

Question 6

Photorespiration definition

Answer 6

a process in which plants take up oxygen rather than carbon dioxide in the light, resulting in photosynthesis being less efficient. (Rubisco takes up O2 instead of CO2)

Question 7

what does rubisco normally do

Answer 7

brings carbon dioxide from the air into the Calvin cycle where the glucose is made, after making it into organic CO2

Question 8

does photorespiration make glucose

Answer 8

nooooo

Question 9

when does photorespiration occur

Answer 9

binds oxygen rather than carbon dioxide

Question 10

why will Rubisco bind to oxygen instead of carbon dioxide

Answer 10

the active site can readily accommodate the oxygen molecules as well as the carbon dioxide molecules, so the two different molecules are in competition for the active site of Rubisco.

Question 11

2 ways photorespiration arise in C3 plants (increase amount)

Answer 11

• temperature increases
• conditions dry out

Question 12

how do C4 plants carry out the Calvin Cycle

Answer 12

carry out an adapted Calvin cycle, in which carbon fixation and glucose production occur in different cells

Question 12

why does photorespiration increase as temperature increases

Answer 12

the ability of the Rubisco enzyme to distinguish between carbon dioxide and oxygen decreases and, as a result, Rubisco will increasingly bind oxygen.

Question 13

why does photorespiration increase as conditions dry out

Answer 13

C3 plants close their stomata to prevent water loss. This closure blocks the entry of carbon dioxide needed as input to the Calvin cycle and limits the exit of oxygen produced

creating a high oxygen low CO2 environment inside the mesophyll cells

Question 14

what are optimal conditions for C4 plants

Answer 14

These cells will thrive in warm and tropical regions

Question 15

what anatomy changes are present in C4 plants (compared to C3 and CAM)

Answer 15

• bundle sheath cells have chloroplasts
• mesophyll cells that are arranged in a close association around the bundle sheath cells

Question 16

where do the two processes occur in C4 plants

Answer 16

leaf mesophyll cells and bundle sheath cells

Question 17

what happens in the first process in C4 plants (light dependent stage)

Answer 17

Carbon dioxide is converted into malic acid, in the mesophyll cells
PEP carboxylase catalyses the binding of carbon dioxide to an acceptor molecule (malic acid) (this is called carbon fixation)

Question 18

what enzyme is used in the first step of C4 plants in photosynthesis

Answer 18

PEP carboxylase

Question 19

why is PEP carboxylase used instead of RuBisco (C4)

Answer 19

It cannot bind to oxygen so photorespiration cannot happen

Question 20

what happens in the second process of the C4 plants

Answer 20

Calvin cycle (glucose production) occurs in the bundle sheath cells

produce a steady supply of carbon dioxide from the breakdown of malic acid that raises the carbon dioxide concentration in their leaves. This allows the RuBisco in the bundle sheath cells to bind only to CO2

Question 21

what are 3 key differences of c3 and c4 plants

Answer 21

• location of calvin cycle, mesophyll in c3, bundle sheath cells c4
• there are chloroplasts in bundle sheath cells in c4
• photorespiration doesn’t normally occur in c4

Question 22

what is accuracy

Answer 22

Accuracy refers to how close an experimental measurement to a known value.

Question 23

what is precision

Answer 23

Precision refers to how close multiple measurements of the same investigation are to each other.

Question 24

what is repeatability

Answer 24

Repeatability is how close results of successive measurements are to each other in the exact same conditions.

Question 25

what is reproducibility

Answer 25

Reproducibility is how close results are when the same variable is being measured (using the same method and investigation) but under different conditions

Question 26

what is validity

Answer 26

The validity of data refers to the credibility of the research results from experiments or from observations.

Question 27

what are random errors

Answer 27

Random errors are chance variations in measurements that affect the precision of measurements.

Question 28

what are systematic errors

Answer 28

errors that affect the accuracy of a measurement and cannot be improved by repeating an experiment. They are usually due to equipment or system errors.

Question 29

1 example of systematic errors

Answer 29

The markings on a ruler are slightly off so that every 1 cm on the ruler is actually 1.1 cm. Therefore, all measurements made using this ruler will be slightly lower than they actually are.

Question 30

1 example of random errors

Answer 30

Measuring the zone of inhibition on an agar plate but not placing the ruler perfectly on the edge of an antibiotic disk each time.