Read the paragraph and answer the following questions.
Partially submerged plants have numerous air spaces inside the stems, leaves, roots that aid in gaseous exchange and buoyancy. Leaf bases of Water Hyacinth (Eichhornia crassipes) form air filled structures to keep them afloat. In water lilies leaves are flat, have an oily surface with stomata present on the upper surface of the leaf, while incompletely submerged plants like Hydrilla, stomata are absent, leaves are thin, stems are highly
FIITJEE WORLD SCHOOL: AMPT, AOC, DSNR, NNG
CLASS-9 | Page -3
Date: 27-10-2020
flexible. The main adaptations that give hydrilla an advantage over other native plants are it can grow at low light intensities, it is better at absorbing carbon dioxide from the wate (diffuses into leaves), it is able to store nutrients for later use, it can tolerate a wide range of water quality conditions for example salinity (can grow in saline waters as well), and can propagate sexually and asexually.
What are the plants which live completely or partially submerged in water called? What are the adaptations seen in water lilies?
iii iv. Name one floating plant. Name the tissue which helps them to float. Which plant can tolerate a wide range of water quality conditions?
Answers
Floating Plants
- American Featherfoil. Azolla (Mosquito Fern) Bladderwort.
- Common Salvinia. Dotted Duckweed. Duckweed.
- Giant Duckweed. Giant Salvinia. Floating Crystalwort.
- Florida Mudmiget. Rooted Water Hyacinth. Watermeal.
- Water Hyacinth. Water Lettuce.
In the aquatic plants a large air cavity is present in parenchyma cells that give buoyancy to the plants and help them to float in the water. This type of parenchyma cell is known as aerenchyma.
Water lilies have a number of adaptations that help them survive in water, including big leaves that float on the water's surface to attract ample sunlight for photosynthesis. The top side of the leaf is covered with a cuticle to keep it as dry as possible, and the underside has thorns to protect against predators.
Emergents are plants that grow with the roots and some portions of the stems and foliage partially submerged in water; the plants' upper portions are visible above the water. Submergent plants are totally submerged, with all parts growing under water. Floating plants are not rooted like emergent or submergent plants.
Answer:
Read the paragraph and answer the following questions.
Partially submerged plants have numerous air spaces inside the stems, leaves, roots that aid in gaseous exchange and buoyancy. Leaf bases of Water Hyacinth (Eichhornia crassipes) form air filled structures to keep them afloat. In water lilies leaves are flat, have an oily surface with stomata present on the upper surface of the leaf, while incompletely submerged plants like Hydrilla, stomata are absent, leaves are thin, stems are highly
FIITJEE WORLD SCHOOL: AMPT, AOC, DSNR, NNG
CLASS-9 | Page -3
Date: 27-10-2020
flexible. The main adaptations that give hydrilla an advantage over other native plants are it can grow at low light intensities, it is better at absorbing carbon dioxide from the wate (diffuses into leaves), it is able to store nutrients for later use, it can tolerate a wide range of water quality conditions for example salinity (can grow in saline waters as well), and can propagate sexually and asexually.
What are the plants which live completely or partially submerged in water called? What are the adaptations seen in water lilies?
iii iv. Name one floating plant. Name the tissue which helps them to float. Which plant can tolerate a wide range of water quality conditions?