Plant Morphology — Set 3
Biology · पादप आकारिकी · Questions 21–30 of 40
Which part of the plant is modified into spines in desert plants like Cactus?
Correct Answer: B. Leaves
In cacti, leaves are modified into spines to reduce water loss through transpiration. The green fleshy stem takes over the function of photosynthesis for the plant. These spines also protect the plant from being eaten by desert animals.
What is the flat, expanded portion of a leaf called?
Correct Answer: D. Lamina
The lamina or leaf blade is the main site for photosynthesis and gas exchange. It is usually thin and broad to capture the maximum amount of sunlight. The petiole is the stalk that attaches this lamina to the stem.
Which type of plant completes its entire life cycle within a single growing season?
Correct Answer: A. Annual
Annuals germinate, flower, produce seeds, and die all within one year or season. Common examples include wheat, rice, and many garden flowers like marigolds. Perennials, by contrast, live for more than two years.
The transfer of pollen grains from the anther to the stigma is called?
Correct Answer: B. Pollination
Pollination is a crucial step in plant reproduction that can occur through wind, water, or animals. Self-pollination happens within the same flower, while cross-pollination involves different flowers. Successful pollination eventually leads to the process of fertilization.
Which modified root provides extra mechanical support in plants like Maize and Sugarcane?
Correct Answer: A. Stilt roots
Stilt roots arise from the lower nodes of the stem and grow into the soil for stability. They help support the tall, slender stems of maize and sugarcane against wind. Pneumatophores, however, are roots modified for respiration in swampy areas.
What is the primary function of the colorful petals in a flower?
Correct Answer: C. Attracting pollinators
Brightly colored petals attract insects and birds that assist in the pollination process. They often have patterns or scents that guide pollinators toward the nectar. All the petals of a flower together are called the corolla.
Which of the following is a ripened ovule?
Correct Answer: B. Seed
After fertilization, the ovule undergoes changes to become a seed containing the embryo. The seed contains food reserves to support the initial growth of the new plant. Fruits are formed from the ripening of the ovary around these seeds.
The arrangement of ovules within the ovary is called?
Correct Answer: C. Placentation
Placentation describes how the ovules are attached to the placenta inside the ovary. Common types include marginal, parietal, and axile placentation. This arrangement is an important diagnostic feature in plant identification.
Which part of the plant is modified into a bulb in onions?
Correct Answer: D. Stem
An onion bulb consists of a highly reduced stem surrounded by fleshy storage leaves. The stem is the small disc-like structure at the bottom from which roots emerge. This modification allows the plant to survive unfavorable dormant periods.
What is the loss of water in the form of vapor from the aerial parts of a plant called?
Correct Answer: A. Transpiration
Transpiration creates a suction pull that helps in the upward movement of water and minerals. It also helps in cooling the plant surface during hot weather conditions. Most transpiration occurs through the stomata present on the leaves.