Test : Plant Life - 2 - Class 5 MCQ

Factors required for the germination of seeds:
There are several factors that are necessary for the germination of seeds. These factors include:
i. Nutrients:
- Seeds contain stored nutrients in the form of carbohydrates, proteins, and fats, which provide the necessary energy for the growth of the embryo during germination.
- These nutrients are broken down into simpler forms by enzymes, which can be utilized by the growing seedling.
ii. Warmth:
- Seeds require a suitable temperature range for germination to occur.
- Different seeds have different temperature requirements, but most seeds germinate well within a temperature range of 20-30 degrees Celsius.
- Warmth is necessary for activating the enzymes involved in the breakdown of stored nutrients and for promoting metabolic activities in the embryo.
iii. Air:
- Oxygen is essential for the process of respiration, which provides energy for the germinating seed.
- The embryo needs oxygen to carry out cellular respiration and produce ATP (adenosine triphosphate), which is required for various metabolic processes during germination.
iv. Water:
- Water is crucial for seed germination as it softens the seed coat and triggers metabolic activities.
- It provides the necessary medium for enzyme activity and helps in the breakdown of stored nutrients.
- Water also helps in the transport of nutrients from the surrounding soil to the growing seedling.
Therefore, all of the given factors (i.e., nutrients, warmth, air, and water) are essential for the germination of seeds. The correct answer is option D: All of these.

• 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

Agents of Dispersal
There are various agents of dispersal that help plants and organisms to spread their seeds or offspring to new locations. The options provided are air, water, and animals. Let's discuss each agent in detail:
Air:
- Wind is an effective agent of dispersal for lightweight seeds or fruits.
- Seeds or fruits can have adaptations such as wings, feathers, or hairs that allow them to be carried by the wind over long distances.
Water:
- Water is an important agent of dispersal for aquatic plants and organisms.
- Seeds or fruits can be buoyant and float on water, allowing them to be carried away to new locations.
Animal:
- Animals play a crucial role in dispersing seeds and propagules.
- Seeds can be dispersed by animals through ingestion and subsequent excretion.
- Some fruits and seeds have adaptations to attract animals, such as bright colors, sweet tastes, or hooks that attach to fur or feathers.
- Animals like birds, mammals, and insects can carry seeds or fruits over long distances.
All of these:
- All the options provided (air, water, and animals) are agents of dispersal.
- Different plants and organisms have different adaptations to utilize these agents for dispersal.
In conclusion, all of the options (air, water, and animals) are agents of dispersal for plants and organisms. They play a crucial role in spreading seeds or offspring to new locations, allowing for the colonization of new areas and the survival of species.

Reproduction through Leaves in Plants

Plants can reproduce through various methods, including the use of their leaves. Among the options provided, the plant that reproduces through its leaves is Bryophyllum (Option B).

Explanation:

• Bryophyllum: Bryophyllum is a succulent plant that belongs to the Crassulaceae family. It is commonly known as the "Mother of Thousands" or "Mother of Millions." This plant has a unique ability to reproduce through its leaves.


• Leaf Reproduction in Bryophyllum: Bryophyllum leaves have small plantlets or buds along their edges. These plantlets can develop and grow into new plants when they fall onto suitable soil or when the leaf touches the ground.


• Advantages of Leaf Reproduction: Leaf reproduction allows Bryophyllum to propagate rapidly and colonize new areas. It provides an efficient means of reproduction, especially in environments with limited resources.


• Other Options: While sugarcane (Option A), banana (Option C), and potato (Option D) are plants with different modes of reproduction, they do not reproduce through their leaves.

Therefore, the correct answer is Bryophyllum (Option B).

Note: It is important to understand that not all plants reproduce through their leaves. Different plants employ various reproductive strategies such as seed production, spore formation, or vegetative propagation through stems or roots.

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.

Plants that grow without seed:
- Banana: Bananas are propagated through a process called vegetative reproduction, where new plants grow from the shoots or suckers of the parent plant. This means that bananas do not require seeds to grow.

- Wheat, Rice, and Maize: These plants are monocots and reproduce through seeds. They do not grow without seeds, so options A, B, and D are incorrect.
In conclusion, the correct answer is C: Banana, as it is a plant that grows without the need for seeds.

Given statements:

• (i) Roots absorb water from soil


• (ii) Roots hold plant firmly in the soil


• (iii) Roots absorb minerals from the soil


• (iv) Roots make food for the plant

Incorrect statement:

• (iv) Roots make food for the plant

Explanation:

Roots have several functions, but they do not make food for the plant. The correct statement about roots is:

• (i) Roots absorb water from soil


• (ii) Roots hold plant firmly in the soil


• (iii) Roots absorb minerals from the soil

Therefore, option B: (i) (ii) (iii) only is the correct answer.

Explanation:
The correct statement regarding the different parts of a plant is that they can grow into a new plant.

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.

The main advantage of vegetative propagation is that it is quicker than seed reproduction. This method allows plants to grow and reproduce faster, often leading to earlier blooming and fruiting compared to plants grown from seeds. This makes vegetative propagation a valuable technique for gardeners and farmers.

Rice and jute grow well in clayey soil that has good water retention properties, whereas other crops like wheat, jowar, and cotton prefer different soil types.