Test: Plant Life - Class 6 MCQ

Insectivorous plants obtain nutrients by trapping insects, which provide essential nitrogen and other minerals, particularly in nutrient-poor environments. This adaptation helps them thrive where traditional nutrient sources are scarce.

Cotyledons serve a vital function in storing food for the developing embryo within the seed. They can also become the first leaves of the new plant, providing energy for initial growth until the plant can photosynthesize.

A bisexual flower contains both male (androecium) and female (gynoecium) reproductive parts, allowing it to self-pollinate or cross-pollinate. This characteristic is essential for reproductive success in many flowering plants.

The first step in seed germination is the absorption of water, which causes the seed to swell and the seed coat to eventually burst. This hydration is crucial for activating the enzymes necessary for growth.

Monocot plants usually exhibit parallel venation, where veins run parallel to each other from the midrib. This pattern is common in grasses and lilies and assists in structural support and efficient water transport.

Transpiration helps to cool the plant by releasing excess water vapor through stomata. This process also aids in nutrient transport from the roots to the leaves and maintains the plant's internal water balance.

The petiole is the short, narrow stalk that connects the leaf blade (lamina) to the stem. This structure supports the leaf and allows it to angle towards the light for optimal photosynthesis.

Sessile leaves are those that are directly attached to the stem without a petiole. This adaptation can provide more stability and reduce the risk of damage from environmental factors.

The thalamus is the enlarged, flattened tip of the pedicel where the flower's whorls arise. It plays a critical role in supporting the flower structure and ensuring proper arrangement of the floral parts for effective reproduction.

The radicle is the part of the seed that develops into the root. It anchors the plant and is the first structure to emerge during germination, allowing the plant to access water and nutrients from the soil.

Self-pollination occurs when pollen is transferred within the same flower or to another flower on the same plant. This method can enhance reproductive efficiency, especially in isolated environments.

Cross-pollination involves the transfer of pollen from the anther of one flower to the stigma of another flower of the same species. This process often enhances genetic diversity, which can improve the resilience and adaptability of plant populations.

The pericarp is the fruit wall developed from the ovary wall. It consists of three layers: epicarp, mesocarp, and endocarp, which protect the seeds and can aid in their dispersal.

The two main parts of a plant are the root system, which grows below the ground and includes the roots, and the shoot system, which grows above the ground and includes the stem, leaves, buds, flowers, and fruits. This distinction is essential for understanding how plants function and adapt to their environments.

Fleshy fruits have a thick, fleshy pericarp, which helps in attracting animals for seed dispersal. Examples include mangoes and cherries, which are not only important for reproduction but also for ecological interactions.

The primary function of a leaf is to manufacture food through the process of photosynthesis, where chlorophyll in the leaves converts sunlight, carbon dioxide, and water into sugars and oxygen. This process is vital for the plant's growth and energy supply.

Light is not a requirement for seed germination; rather, seeds need water, air (oxygen for respiration), and suitable temperature conditions to activate their metabolic processes and begin growth.

The sepals form the calyx, which is the outermost whorl of a flower. The calyx protects the flower bud before it blooms and can sometimes contribute to the flower's overall appearance.

A compound leaf is characterized by its lamina being divided into smaller leaflets, which are attached to a central stalk. This structure can help reduce damage from wind and maximize light capture.

Leaves exchange gases primarily through a process called stomatal exchange. This involves small openings on the leaf surface known as stomata. Here’s how it works:

• Stomata open to allow carbon dioxide (CO₂) to enter the leaf for photosynthesis.
• Oxygen, a by-product of photosynthesis, exits the leaf through the same stomata.
• Water vapour also leaves the leaf during this process, which is part of transpiration.
• The opening and closing of stomata are controlled by guard cells, which respond to environmental conditions.

This gas exchange is vital for the plant’s ability to produce energy and maintain its health.