TRANSPORT IN PLANTS
2020 MARCH
1. Observe the figure given below: (Score 2)
a. Name the process.
b. Define the above identified process.
Answer:
Facilitated diffusion (Facilitated transport).
It is the diffusion of hydrophilic substances across a membrane along the concentration gradient through some transport proteins.
2019 JULY IMPROVEMENT
1. Though transpiration results in loss of water, it has many purposes.
List out any four advantages of transpiration. (Score 2)
Answer:
i. Creates transpiration pull for absorption and transport of
plants.
ii. Supplies water for photosynthesis.
iii. Transports minerals from the soil to all parts of the
plant.
iv. Cools leaf surfaces.
v. Maintains shape and structure of plants by keeping cells
turgid.
2019 MARCH
1. Observe the figure given below:
Identify the
process demonstrated in the figure.
Write the role of membrane in this
process. (Score 2)
Answer:
Osmosis/Diffusion of
water across the membrane.
Functions: Active transport and passive transport.
2018 JULY IMPROVEMENT
1. The opening and closing of stomata is aided by the peculiarities of bean
shaped guard cells. Mention any two such peculiarities. (Score 2)
Answer:
The
inner wall of guard cells is thick and elastic.
Outer
wall remains thin.
2018 MARCH
1. State any four features of facilitated diffusion. (2)
Answer:
·
Requires
special membrane proteins.
·
Highly
selective.
·
Transport
saturates.
·
Not
requires ATP energy.
2017 JULY (IMPROVEMENT)
1. A cell when placed in a concentrated
sucrose solution, shrink after few hours. Identify the physical phenomenon that
leads to shrinkage of cell and justify your answer. (2)
Answer:
Plasmolysis.
Water molecules move out of the cell (exosmosis).
Cell
membrane becomes shrink away from the cell wall.
2017 MARCH
1. The movement of water through the root
layers is ultimately symplastic in the endodermis. Give a reason. (2)
Answer:
This is the only way
water and solutes can enter the vascular cylinder.
2016 MARCH
1. How can you differentiate active
transport from facilitated diffusion? (2)
Answer:
In active transport, transport proteins and energy are
used.
In
facilitated diffusion- transport protein only is used.
2015 SEPTEMBER (IMPROVEMENT)
1. Define imbibition and give one example studied by you. (2)
Answer:
It
is a type of diffusion in which water is absorbed by solids (colloids)
increasing their volume. E.g. absorption of water by seeds and dry wood.
2015 MARCH
1. Transpiration has more than one purpose in plants. Write any one purpose
of transpiration in plants and list any two factors that affect this process. (2).
Answer:
Transpiration
creates transpiration pull for absorption of water and transport of minerals.
Factors affecting transpiration: Temperature, light, humidity, wind, number of stomata etc.