Test : Plant Life - 2 - Class 5 MCQ

To help seeds germinate, several important factors are needed:

• Nutrients - These provide the necessary food for growth.
• Warmth - Seeds need a warm environment to start growing.
• Air - Seeds require oxygen to grow.
• Water - Moisture is essential for seeds to sprout.

All these factors work together to ensure successful germination.

• Avoid Over-Crowding: Dispersal prevents competition for resources like sunlight, water, and nutrients, promoting healthier growth.
• Independence from Parent Plant: Seeds dispersed away from the parent plant reduce resource competition and avoid diseases and pests that may affect the parent plant.
• Spread to New Areas: Dispersal allows plants to colonize new areas, increasing their distribution and genetic diversity, which enhances their ability to adapt to changing environments.

Thus, the correct answer is C: (i), (ii), and (iii).

The correct match of seed and its means of dispersal is: C. Cotton seeds - Air
- Cotton seeds are lightweight and have structures called trichomes, which are hair-like projections that help them catch the wind and get dispersed.
- The air currents carry the cotton seeds to new locations, allowing them to spread over large distances.
- This method of dispersal is known as anemochory, or wind dispersal.
- Cotton seeds are not dispersed by water (Pomegranate - water) or animals (Coconut - Animal, Pea - Animal).
Therefore, the correct pair is C: Cotton seeds - Air.

When a seedling starts to grow, it relies on stored food from its cotyledons. Once this food is used up, the cotyledons become smaller and eventually fall off. This is a normal part of the plant's growth process.

• The cotyledons are the first leaves that appear.
• They provide essential nutrients to help the seedling grow.
• After the seedling has used all the food, it can start making its own food through photosynthesis.

To classify the given crops in Rabi and Kharif, we need to understand the cropping seasons of these crops. Rabi crops are sown in winter (November-December) and harvested in spring (April-May), while Kharif crops are sown at the beginning of the monsoon season (June-July) and harvested in autumn (September-October). Based on this information, we can classify the given crops as follows:
Classification of crops:
- Wheat: Rabi
- Maize: Kharif
- Bajra: Kharif
- Gram: Rabi
Therefore, the correct classification of the given crops in Rabi and Kharif is:
Answer: A
- (i) Wheat - Rabi
- (ii) Maize - Kharif
- (iii) Bajra - Kharif
- (iv) Gram - Rabi

Dispersal refers to how seeds, plants, and animals can move from one place to another. Here are the main agents of dispersal:

• Air: Wind can carry seeds and small organisms over long distances.
• Water: Seeds can float on water and travel to new areas, like rivers and oceans.
• Animals: Animals can help in dispersal by eating fruits and spreading seeds through their droppings.

All of these methods—air, water, and animals—are important for spreading plants and seeds to new locations, making option D the correct choice.

One plant that reproduces through its leaves is the Bryophyllum. This plant has special leaves that can grow new plants. Here are some key points:

• The leaves of Bryophyllum can produce small plantlets.
• These plantlets can grow into new plants when they fall off and take root.
• This type of reproduction is called asexual reproduction.

Other plants like sugarcane, banana, and potato do not reproduce mainly through their leaves.

Rhizomes have roots growing from the bottom and green leaves from the top. They are a type of underground stem that allows plants to store nutrients and produce new shoots. Here are some key points about rhizomes:

• They help in vegetative reproduction, allowing plants to spread.
• Rhizomes can grow horizontally, which supports stability in the soil.
• Many plants, such as ginger and bamboo, use rhizomes for growth.

This adaptation is crucial for survival in various environments.

Mode of Dispersal for Coconut Seedling
Air:
- Coconut seedlings are not typically dispersed by air as their large size and weight make it difficult for them to be carried by wind.
Animal:
- Animals, such as birds and mammals, may consume coconuts and their seedlings and then excrete them in a different location, allowing for dispersal.
- However, in the case of a coconut seedling growing on a sea shore, the chances of animal dispersal may be relatively low as there may be limited animal activity in that specific environment.
Explosion:
- The explosion is not a mode of dispersal for coconut seedlings.
Water:
- Water is the most likely mode of dispersal for a coconut seedling growing on a sea shore.
- The strong ocean currents and tides can carry the seedling away from its original location and deposit it onto another shore.
- The buoyant nature of coconut seedlings allows them to float on water and be transported over long distances.
In this case, the most suitable mode of dispersal for the coconut seedling growing on a sea shore would be water.

Roots play an important role in the growth of plants. Here’s what they do:

• Absorb water: Roots take in water from the soil, which is essential for the plant's survival.
• Hold the plant: Roots anchor the plant firmly in the soil, preventing it from falling over.
• Absorb minerals: Roots also take in important minerals from the soil that help the plant grow.
• Roots do not make food for the plant; this job is done by the leaves through a process called photosynthesis.

Therefore, the correct options are those that mention the roles of roots in absorbing water and minerals, and holding the plant in place.

The different parts of a plant, such as seeds, stems, leaves, and spores, play important roles in its growth.

• Seeds contain stored food that helps them grow into new plants.
• Stems support the plant and carry water and nutrients.
• Leaves are where the plant makes food using sunlight, air, and water.
• Spores can help the plant spread and grow in new places.

Among these, the correct statement is that they can grow into new plants when given the right conditions.

Vegetative propagation is a method of plant reproduction that does not involve seeds. There are several common techniques, including:

• Cutting: This involves taking a part of the plant, like a stem or leaf, and placing it in soil or water to grow roots.
• Budding: In this process, a new plant grows from a bud on the parent plant. This is often used in grafting.
• Layering: This technique encourages a stem to root while still attached to the parent plant. Once rooted, it can be severed to grow independently.

All of these methods are effective ways of propagating plants without using seeds.