1. On which part of a flower does a pollen grain usually germinate?
A.
Anther
B.
Stigma
C.
Filament
D.
Sepal
Correct Answer:
Stigma
Explanation:
A pollen grain generally germinates after landing on the receptive surface of the stigma.
2. What does a pollen grain produce during germination?
A.
A pollen tube
B.
A root
C.
A leaf
D.
A seed coat
Correct Answer:
A pollen tube
Explanation:
During pollen germination, the intine grows out through a germ pore to form the pollen tube.
3. Through which opening does the pollen tube usually emerge from a pollen grain?
A.
Nucleus
B.
Germ pore
C.
Vacuole
D.
Cell wall of the stigma
Correct Answer:
Germ pore
Explanation:
The pollen tube emerges through a thin or absent region of the exine called the germ pore.
4. What is the first important requirement for pollen germination on the stigma?
A.
Water and suitable nutrients
B.
Complete darkness
C.
Removal of the ovary
D.
Formation of a seed
Correct Answer:
Water and suitable nutrients
Explanation:
Pollen grains require moisture and suitable nutrients from the stigma for germination and pollen tube growth.
5. Which part of the pollen grain grows to form the pollen tube?
A.
Exine
B.
Intine
C.
Pollen coat only
D.
Outer layer of the stigma
Correct Answer:
Intine
Explanation:
The inner wall layer of the pollen grain, called the intine, protrudes through the germ pore and forms the pollen tube.
6. In which direction does the pollen tube generally grow after pollen germination?
A.
Away from the flower
B.
Through the stigma and style
C.
Into the anther wall
D.
Into the petals
Correct Answer:
Through the stigma and style
Explanation:
After germination on the stigma, the pollen tube grows through the stigma and style toward the ovary.
7. Which pollen grain component contains the material needed for pollen tube growth?
A.
Cytoplasm
B.
Exine only
C.
Stigma surface
D.
Sepal tissue
Correct Answer:
Cytoplasm
Explanation:
The cytoplasm of the pollen grain provides the cellular material needed for the formation and growth of the pollen tube.
8. What happens to a compatible pollen grain after it reaches the stigma?
A.
It absorbs moisture and germinates
B.
It becomes a sepal
C.
It loses its cell wall immediately
D.
It changes into an ovule
Correct Answer:
It absorbs moisture and germinates
Explanation:
A compatible pollen grain absorbs water from the stigma and begins pollen germination by producing a pollen tube.
9. Which cell of a germinating pollen grain is mainly responsible for forming the pollen tube?
A.
Vegetative cell
B.
Egg cell
C.
Central cell
D.
Synergid
Correct Answer:
Vegetative cell
Explanation:
The vegetative cell enlarges and forms the pollen tube during pollen germination.
10. What is the main function of the pollen tube formed during pollen germination?
A.
To provide a pathway for the male gametes
B.
To produce petals
C.
To form the stigma
D.
To absorb minerals from the soil
Correct Answer:
To provide a pathway for the male gametes
Explanation:
The pollen tube grows through the female floral tissues and serves as a passage for transporting the male gametes.
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