Q1. Which of the following roots grow downward from branches and anchor upon reaching the ground?
- Stilt roots
- Prop roots
- Lateral roots
- Pneumatophores
Correct Option: 2. Prop roots
Explanation: Prop roots are aerial adventitious roots growing from branches or the trunk, which:
• Grow downward, then anchor into the soil.
• Provide mechanical support to heavy or wide-spreading branches.
• Are typical of the Banyan tree (Ficus benghalensis).
They differ from stilt roots, which arise from the lower stem, and pneumatophores, which function in gas exchange in swamps.
Q2. What scientific method uses annual rings to determine the age of a tree?
- Phenology
- Arboriculture
- Dendrochronology
- Paleobotany
Correct Option: 3. Dendrochronology
Explanation: Dendrochronology is the science of determining the age of a tree by counting its annual rings.
• Each year, a tree forms a new growth ring.
• These rings can also give insight into past climatic conditions, known as paleoclimatology.
• Wider rings indicate favorable growing seasons; narrower rings indicate stress (drought, cold, etc.).
It’s a crucial tool in ecology, archaeology, and climate science.
Q3. Parthenium (Congress grass) is mainly considered a problematic weed in which of the following areas?
- Desert ecosystems
- Cultivated fields and wastelands
- Alpine forests
- Mangroves
Correct Option: 2. Cultivated fields and wastelands
Explanation: Parthenium hysterophorus, or Congress grass, is an invasive weed native to North America and widely spread throughout India.
• Found in fields, roadsides, forest edges, and wastelands.
• It reduces crop productivity and is harmful to humans and livestock.
• Causes skin allergies, asthma, and displaces native vegetation.
Its control is difficult due to its prolific seed production and fast growth.
Q4. Which of the following trees is a partial root parasite?
- Teak
- Sal
- Sandalwood
- Neem
Correct Option: 3. Sandalwood
Explanation:Sandalwood (Santalum album) is a partial root parasite:
• Begins as an independent seedling, then connects its roots to nearby plants to extract water and minerals via haustoria.
• It still performs photosynthesis to make its own food.
• Cannot grow effectively without a host plant, especially during early growth.
This unique adaptation makes it valuable but also challenging to cultivate.
Q5. Which of the following best describes the role of leaves in a tree?
- Store nutrients for later use
- Convert solar energy into food via photosynthesis
- Anchor the tree into the soil
- Serve only as shade structures
Correct Option: 2. Convert solar energy into food via photosynthesis
Explanation:Leaves are the photosynthetic organs of a tree.
• Contain chlorophyll, which captures sunlight energy.
• Use this energy to convert CO₂ + water into glucose (food) and oxygen.
• The food supports tree growth, and the oxygen is released into the atmosphere.
Thus, leaves play a crucial ecological role and are often referred to as the lungs and kitchens of the planet.