Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Adaptation is the process by which plants develop special features to survive in their specific environment or habitat.
Terrestrial plants grow on land and are categorized based on their terrain: Deserts, Mountains, Plains, and Marshes.
Desert plants (Xerophytes) like the Cactus have leaves reduced to spines to prevent water loss via transpiration ( loss) and perform photosynthesis in their fleshy green stems.
Plants in hilly areas, like Pine and Fir trees, are cone-shaped with needle-like leaves and a waxy coating to allow snow to slide off easily.
Mangroves grow in marshy, clayey soil and have special 'breathing roots' called pneumatophores to absorb oxygen () directly from the air.
Aquatic plants (Hydrophytes) can be floating (e.g., Duckweed), fixed (e.g., Lotus), or underwater (e.g., Hydrilla). Fixed aquatic plants have stomata on the upper surface of their broad leaves.
Insectivorous plants like the Venus Flytrap grow in nitrogen-deficient soil and trap insects to fulfill their nitrogen requirements.
Non-green plants like Mushrooms and Fungi lack chlorophyll and obtain nutrients from dead and decaying matter.
📐Formulae
💡Examples
Problem 1:
Why do plants like the Lotus have a thick waxy coating on their leaves and stomata only on the upper surface?
Solution:
To prevent the leaves from rotting and to facilitate gas exchange ( and ) while floating.
Explanation:
Since the lower surface of the Lotus leaf is in constant contact with water, stomata on the bottom would be blocked and ineffective. The waxy coating makes the leaf waterproof, preventing from clogging the pores or causing the leaf to decay.
Problem 2:
How does the shape of a Coniferous tree help it survive in cold, snowy mountains?
Solution:
The conical shape and sloping branches allow snow to slide off easily.
Explanation:
In high altitudes where snowfall is common, the sloping branches prevent the accumulation of heavy snow, which would otherwise break the branches. The needle-like leaves also have a small surface area to reduce loss during frozen winters.
Problem 3:
Identify the adaptation used by the Pitcher plant to survive in poor soil.
Solution:
It traps and digests insects to obtain nitrogen.
Explanation:
The soil in which Pitcher plants grow lacks essential minerals like Nitrogen. The plant modifies its leaf into a 'pitcher' with a lid to trap insects. Once trapped, the insect is digested by enzymes to provide the necessary nutrients for the plant's growth.