Unit Test (Solutions): Reproduction in Plants | Science Class 7 (Old NCERT) PDF Download

Time: 1 hour
Maximum Marks: 30
Attempt all questions.

• Question numbers 1 to 5 carry 1 mark each.
• Question numbers 6 to 8 carry 2 marks each.
• Question numbers 9 to 11 carry 3 marks each.
• Question numbers 12 & 13 carry 5 marks each.

Q1: Which of the following is an example of vegetative reproduction by stems?  (1 Mark)
(a) Rose
(b) Mango
(c) Papaya
(d) Coconut
Ans: (a) Rose
Vegetative propagation in rose occurs through stem cutting.

Q2: What is the male reproductive part of a flower?  (1 Mark)
Ans: Stamen
The stamen consists of anther and filament and produces pollen grains.

Q3: Which type of flower has both male and female reproductive parts?  (1 Mark)
(a) Unisexual flower
(b) Bisexual flower
(c) Incomplete flower
(d) None of these
Ans: (b) Bisexual flower
Bisexual flowers like hibiscus and mustard contain both stamen and pistil.

Q4: Name a plant that reproduces asexually through leaves.  (1 Mark)
Ans: Bryophyllum
The leaves of Bryophyllum have buds on their edges, which develop into new plants.

Q5: What is the function of pollen grains in reproduction?  (1 Mark)
Ans: Pollen grains contain the male gametes, which fertilize the female gametes (ovules) in the ovary.

Q6: Differentiate between self-pollination and cross-pollination.  (2 Marks)
Ans:

Q7: What is the role of spores in reproduction?  (2 Marks)
Ans:

• Spores are reproductive structures found in fungi and some plants.
• They have a protective covering, allowing them to survive harsh conditions.
• When favorable conditions return, spores germinate and grow into new organisms.

Q8: How does fragmentation help in plant reproduction? Give an example.  (2 Marks)
Ans:

• In fragmentation, the plant body breaks into pieces, and each piece grows into a new plant.
• Example: Spirogyra (algae) reproduces by breaking into fragments, which later grow into complete plants.

Q9: Explain the process of budding in yeast with a diagram.  (3 Marks)
Ans:

• Budding is a form of asexual reproduction in yeast.
• A small outgrowth (bud) appears on the parent yeast cell.
• The bud enlarges, receives cytoplasm, and eventually detaches to become a new yeast cell.
  

Q10: Describe three different methods of seed dispersal with examples.  (3 Marks)
Ans:

1. By Wind: Light seeds with wing-like structuresfloat in the air.
   • Example: Drumstick, Maple.
2. By Water: Seeds with fibrous husksfloat and travel through water.
   • Example: Coconut.
3. By Animals: Spiny seeds attach to animal furand get carried away.
   • Example: Xanthium, Urena.

Q11: How does a seed develop into a new plant?  (3 Marks)
Ans:

1. The seed absorbs water, softens, and swells.
2. The radicle (root) emerges first, growing into the soil.
3. The plumule (shoot) grows upwards towards the light.
4. The stored food in the seed helps the young plant grow until it can perform photosynthesis.

Q12: Explain the steps of fertilization in flowering plants with a diagram. (5 Marks)
Ans:

1. Pollination: Pollen is transferred from the anther to the stigma.
2. Pollen tube formation: The pollen grain develops a tube that grows towards the ovule.
3. Fusion of gametes: The male gamete (from pollen) fuses with the female gamete (egg cell) inside the ovule.
4. Zygote formation: The fertilized egg develops into a zygote, which later forms an embryo.
5. Seed and fruit formation: The ovule develops into a seed, and the ovary becomes a fruit.
   

Q13: Describe vegetative reproduction by stem, root, and leaves with examples. (5 Marks)
Ans:

1. Stem Cutting:
   • A cut stem piece of a plant is planted in soil, which develops roots and shoots.
   • Example: Rose, Sugarcane.
2. Root Tubers:
   • Thickened roots store food and develop shoot buds that grow into new plants.
   • Example: Dahlia, Sweet Potato.
3. Leaf Buds:
   • Some plants have buds on their leaf margins that grow into new plants.
   • Example: Bryophyllum.