نباتات میں ضیائی تالیف اور نقل و حمل

Written by Dr. Hira Salman (Biology)

ایم ڈی کیٹ · حیاتیات · 6 سوالات

نام: ____________________ تاریخ: ____________

The light reactions of photosynthesis take place in the:
- A Stroma
- B Cytoplasm
- C Mitochondria
- D Thylakoid membranes
Which enzyme fixes carbon dioxide in the Calvin cycle?
- A Amylase
- B ATP synthase
- C Catalase
- D RuBisCO
Water moves up the xylem mainly because of:
- A Active transport in xylem vessels
- B Root pressure alone
- C Osmosis in the leaf only
- D Transpiration pull and cohesion
Stomata open when the guard cells become:
- A Turgid
- B Flaccid
- C Plasmolysed
- D Dead
Which substance is mainly transported in the phloem?
- A Oxygen
- B Water and minerals
- C Sucrose
- D Starch
Auxins promote:
- A Seed dormancy
- B Fruit ripening only
- C Leaf fall
- D Cell elongation

جوابی کلید

1. D, 2. D, 3. D, 4. A, 5. C, 6. D

Light is absorbed by chlorophyll in the thylakoid membranes of the grana. The Calvin cycle happens in the stroma.
RuBisCO attaches carbon dioxide to ribulose bisphosphate, the first step of carbon fixation.
Water evaporating from leaves pulls a continuous column of water upward. Cohesion between water molecules keeps the column unbroken.
When guard cells take up water and become turgid, their shape bends and the pore opens.
Phloem carries sucrose from sources, such as leaves, to sinks, such as roots and fruits. This is called translocation.
Auxin makes cells in the shoot elongate. Uneven auxin on two sides of a shoot causes bending toward light (phototropism).