FBISE Class 9th (SSC-l)
Explore subjects and practice MCQs
3
Chapters
1,610
Total MCQs
FBISE Class 9th (SSC-l)
Answer: Transpiration cools the leaves and helps in the transport of water and minerals.
1362
Answer: When water loss is greater than absorption, cells lose turgor and the plant wilts.
Answer: Adhesion is the attraction of water molecules to the xylem walls, helping water rise.
Answer: Cohesion is the attraction between water molecules that keeps the xylem water column unbroken.
Answer: The cuticle is a waxy coating that limits cuticular transpiration.
Answer: Active uptake of minerals draws water into the xylem, building up positive root pressure.
Answer: Guttation takes place through hydathodes, not through the stomata.
1368
Answer: Hydathodes are special pores at the margins of leaves that release water droplets during guttation.
Answer: Guttation water is not pure; it contains dissolved minerals that came up with the xylem sap.
Answer: Oxygen is produced when water molecules are split during the light reactions of photosynthesis.
Answer: In darkness photosynthesis stops while respiration continues, so the plant releases carbon dioxide.
Answer: Xylem consists of vessels, tracheids, xylem fibres and xylem parenchyma.
Answer: Vessels and tracheids conduct water and give the stem mechanical support.
Answer: Phloem consists of sieve tubes, companion cells, phloem fibres and phloem parenchyma.
Answer: Companion cells keep sieve tubes alive and functional through their nucleus and metabolism.
Answer: Sieve tube cells have no nucleus and rely on companion cells for their functioning.
Answer: The cohesion-tension mechanism sustains a continuous water column that can reach the tops of tall trees.
Answer: Mesophyll cells of the leaves contain most of the chloroplasts where photosynthesis occurs.
Answer: Mesophyll cells are packed with chloroplasts and are the main sites of photosynthesis.
Answer: Plants excrete gases such as carbon dioxide and oxygen and also water, but urea is not a normal plant waste.