All questions of Plants for Grade 4 Exam

Understanding Parasitic and Insectivorous Plants
Parasitic and insectivorous plants are two unique types of plants that have adapted to obtain nutrients in different ways.
Main Difference
- Photosynthesis Capability
- Parasitic plants typically do not perform photosynthesis. They rely on other plants for nutrients by attaching to their hosts and extracting water and nutrients directly from them.
- In contrast, insectivorous plants can perform photosynthesis. They have chlorophyll and can create their food using sunlight, just like most plants do.
Characteristics of Parasitic Plants
- Dependency on Host Plants
- They depend entirely on other plants for survival.
- Examples include mistletoe and dodder, which extract nutrients from their host plants.
- Lack of Photosynthesis
- Many parasitic plants have lost the ability to photosynthesize due to their reliance on host plants.
Characteristics of Insectivorous Plants
- Nutrient Acquisition Through Insects
- These plants trap insects to supplement their nutrient intake, especially nitrogen, which is often limited in their environments.
- Examples include Venus flytrap and pitcher plants.
- Ability to Photosynthesize
- Insectivorous plants still perform photosynthesis, allowing them to generate energy independently from the insects they consume.
Conclusion
In summary, the major difference is that parasitic plants do not perform photosynthesis, while insectivorous plants do. This distinction highlights the unique adaptations these plants have made to survive in their respective environments.

Understanding Parasitic Plants
Parasitic plants are unique organisms that have evolved to thrive by obtaining nutrients from other plants rather than from the soil. This adaptation allows them to survive in environments where resources are limited.
How Parasitic Plants Obtain Nutrients
- Absorbing Nutrients from Hosts:
Parasitic plants attach themselves to host plants through specialized structures called haustoria. These haustoria penetrate the host's tissues, allowing the parasite to directly draw water and nutrients.
- Types of Parasitic Plants:
There are two main types of parasitic plants:
- Holoparasites: These plants are completely dependent on their host for survival and typically do not perform photosynthesis. They obtain all their nutrients from the host.
- Hemiparasites: These plants can perform photosynthesis but still rely on their host for water and certain nutrients, making them partially dependent.
Why Photosynthesis is Not a Primary Method
- Limited Photosynthesis:
While some parasitic plants can photosynthesize, their primary method of nutrient acquisition remains parasitism. They often grow in shaded or nutrient-poor environments where sunlight is limited, reducing their ability to rely solely on photosynthesis.
- Advantage of Parasitism:
By tapping into the nutrient-rich xylem and phloem of host plants, parasitic plants can thrive without competing for soil nutrients, which can be especially beneficial in challenging environments.
Conclusion
In summary, parasitic plants primarily obtain their nutrients by absorbing them from other plants, making option 'C' the correct answer. This fascinating adaptation enables them to survive in various ecological niches, showcasing the diversity of plant life.

Adaptations of Cacti in Arid Conditions
Cacti are remarkable plants that thrive in dry, arid environments where water is scarce. Their unique adaptations allow them to survive and even flourish under such challenging conditions.
Water Storage
- Cacti have specialized stems that can store large amounts of water.
- The thick, fleshy stems act like water reservoirs, allowing the plant to draw on this stored water during long periods of drought.
Modified Leaves
- Instead of broad leaves, cacti have spines.
- Spines reduce water loss by minimizing the surface area that is exposed to the sun and air, which helps to prevent evaporation.
Root System
- Cacti often have extensive root systems that can be shallow and spread out to catch water from light rains.
- Some species also develop deep roots to access groundwater, but the primary adaptation is their efficient use of surface moisture.
Photosynthesis
- Cacti utilize a unique form of photosynthesis called CAM (Crassulacean Acid Metabolism).
- This method allows them to open their stomata at night, reducing water loss while still taking in carbon dioxide for photosynthesis.
Conclusion
These adaptations make cacti perfectly suited for their arid habitats, helping them conserve water and survive harsh environmental conditions. By storing water in their stems, they ensure they have a reservoir to rely on during dry spells.

Modified structures of Pitcher plant leaves
Pitcher plants, like many other carnivorous plants, have modified structures on their leaves to aid in trapping and digesting insects for additional nutrients. These modifications serve specific purposes that help the plant thrive in environments where nutrients are limited.

Trapping mechanism
The pitcher plant's leaves are shaped like a pitcher, hence the name, with a deep cavity that contains a fluid filled with digestive enzymes. This structure allows the plant to attract, trap, and digest insects that fall into the pitcher. The slippery walls of the pitcher prevent insects from escaping once they enter, leading to their eventual digestion.

Additional nutrient source
Pitcher plants grow in nutrient-poor environments, such as bogs and marshes, where the soil lacks essential nutrients like nitrogen. By trapping and digesting insects, the pitcher plant can obtain the nutrients it needs to supplement its diet. This carnivorous behavior helps the plant survive and thrive in habitats where other plants may struggle to obtain enough nutrients.

Adaptation to environment
The modified structures of pitcher plant leaves are an adaptation to the plant's environment. The ability to capture and digest insects gives the plant a competitive advantage in nutrient-poor soils. This unique strategy allows the pitcher plant to thrive in habitats where traditional methods of obtaining nutrients, such as through the soil, may not be sufficient.
In conclusion, the modified structures of pitcher plant leaves, specifically the pitcher-shaped cavity with digestive fluid, serve the important function of trapping and digesting insects for additional nutrients. This adaptation helps the plant survive in nutrient-poor environments and demonstrates the remarkable diversity of strategies that plants have evolved to thrive in challenging conditions.

Understanding Photosynthesis
Photosynthesis is the remarkable process by which plants convert light energy into chemical energy. This process enables them to produce their own food, making the statement true. Here’s a breakdown of how it works:
Key Components of Photosynthesis
- Light Energy: Plants absorb sunlight through their leaves.
- Chlorophyll: This green pigment found in leaves captures sunlight.
- Water and Carbon Dioxide: Plants take in water from the soil and carbon dioxide from the air.
The Photosynthesis Process
1. Absorption of Light: Chlorophyll absorbs sunlight.
2. Water Splitting: The absorbed light energy splits water molecules into hydrogen and oxygen.
3. Carbon Fixation: Carbon dioxide combines with hydrogen to form glucose, a simple sugar.
4. Oxygen Release: Oxygen, a by-product, is released into the atmosphere.
Why Photosynthesis is Important
- Food Production: It produces glucose, which serves as food for the plant and is essential for growth.
- Oxygen Generation: Provides oxygen, vital for the survival of most living organisms.
- Foundation of Food Chains: Plants are primary producers, forming the basis of food webs.
Conclusion
In summary, the statement that "Plants make their own food in a process called photosynthesis" is indeed true. This process is vital not only for the plants themselves but also for the entire ecosystem, supporting life on Earth.

A habitat provides everything an organism needs to survive, including food, water, shelter, and appropriate living conditions. For plants, this means having the necessary resources to grow and reproduce, even in varied and extreme environments like deserts, mountains, and underwater regions. Adaptations help plants thrive in these diverse habitats.

Understanding Plant Adaptation
Plant adaptation refers to the changes that plants undergo to survive in their environments. These adaptations help them deal with challenges such as harsh weather, limited water, and threats from herbivores.
Why Option C is Correct
- Using Thorns for Protection:
One of the most effective adaptations plants have developed is the use of thorns. These sharp structures serve as a defense mechanism to deter animals from eating them. By scaring off potential herbivores, plants increase their chances of survival and reproduction.
- Examples of Plants with Thorns:
- Cacti: Many cacti have thorns that not only protect them from animals but also reduce water loss by providing shade.
- Roses: Rose bushes have thorns that prevent animals from munching on their leaves and flowers.
Why Other Options Are Not Adaptations
- Growing Faster:
While growing faster can be beneficial, it is not a specific adaptation to a threat. Instead, it is a general growth response to environmental conditions.
- Changing Leaf Color in the Fall:
This is a seasonal change that helps plants prepare for winter, but it is not a defensive adaptation against threats.
- Releasing Fragrance During the Day:
While this can attract pollinators, it is not a protective adaptation aimed at survival against herbivores.
Conclusion
In summary, using thorns to scare off animals is a clear example of plant adaptation as it directly impacts the plant's ability to survive and thrive in its environment.

Understanding Hilly Trees like Pine
Hilly trees, particularly pines, are fascinating plants that exhibit unique characteristics. Let's analyze the statements provided to identify which one is false.
Statement Analysis
- a) They do not have flowers.
- This statement is true. Pines are gymnosperms, meaning they reproduce using cones instead of flowers.
- b) They are dome shaped.
- This statement is false. While some trees may have a dome shape, pines typically have a more conical or pyramidal shape, especially when they are young. Their branches extend outward and upward, creating a distinctive silhouette that is not dome-like.
- c) They are conifers.
- This statement is true. Pines belong to the conifer family, which means they bear cones and have needle-like leaves.
- d) Their leaves are needle-shaped.
- This statement is also true. Pine trees have long, slender leaves that resemble needles, which help reduce water loss and withstand cold climates.
Conclusion
In summary, the false statement among the options is that hilly trees like pines are dome-shaped. Instead, they have a conical shape, making them easily recognizable in forests and hilly areas. Understanding these characteristics helps us appreciate the adaptability and beauty of pine trees in their natural habitats.

Hydrilla leaves are thin and narrow, which allows water to pass through them easily without causing damage. This adaptation helps the plant survive in the flowing water environment. Additionally, this feature prevents the leaves from tearing due to water movement, ensuring the plant remains intact.

Floating plants like duckweed have spongy leaves filled with air spaces, which help them float on the water. This makes it easier for the plant to get sunlight and stay stable on the water surface.

Fixed aquatic plants, such as water lilies, have stomata on the upper side of their leaves to take in air. This is important because their leaves float on the water, so having stomata on top allows them to get the carbon dioxide they need for photosynthesis.

Fixed aquatic plants, like water lilies, have broad leaves with a waxy surface that helps them float on the water. The waxy coating keeps the leaves dry and prevents them from rotting.