Biology Assertion Reason Questions Part 4

  • Brown algae are not damped when waves beat them against rocks in the ocean due to presence of phycocolloids in their cell walls.
  • Red algae are deepest in seas as they have phycoerythin, which can capture blue green light reaching greatest depth in seas.
  • Algae blooms deplete dissolved oxygen levels in polluted water bodies & increase bio production of water bodies due to algal blooms.
  • After forest fire, ferns are often the first plant to appear. Rhizome of fern survives the forest fire & develops new leaves.
  • Conifers are able to reduce loss of water by transpiration. A conifer needle promotes a streamlined flow of air.
  • Conifers needles require lesser water for cooling by evaporation as compared to young fern fronds. As life size, increase the amount of cooling by conduction decreases.
  • It is possible to identify nodes of a stem as leaves arise from nodes.
  • Mango tree appears dome shaped. In mango the growth of main stem slows down after sometime.
  • It is possible to distinguish leaf from a leaflet bud is never present in axil of a leaflet.
  • It is advisable to harvest radish at the end of first year of growth itself. The entire food stored in radish is drawn up into the inflorescence by the end of second year.
  • Inspite of absence of nuclei, seive tubes continue live. A companion cell is associated with each seive tube.
  • Seive tube & companion cells are called sister cells. They arise from same mother cells.
  • Wood is made of xylem not phloem. All old phloem cells are periodically sloughed off:
  • Pollen grains are well preserved during pollination
  • Plants of family papilionaceae are used in crop rotation as they have root nodules.
  • Ovary of cucurbits is unilocular but appears trilocular as placenta intrudes making the ovary appear trilocular.
  • Barley flour cannot be used for bread as it contains little or no gluten.
  • Vegetable prevents constipation as they have high percentage of roughage.
  • Rate of transpiration is indirect measure of photosynthesis as it indicates degree & period of stomatal opening.
  • Plant of arid region with adaptation to reduce transpiration usually show body growth redaction in degree & period of stomatal opening.
  • Uptake of minerals is specific carrier proteins have specific sites for binding ions that are to be transported.
  • When roots are deprived of O2 they show drop in active absorption of minerals for active absorption energy is needed obtained from ATP.
  • P680 is responsible for photolysis of water. When it is missing electrons it becomes a strong oxidizer & pulls electrons out of water.
  • Chloroplast can synthesis glucose in ab light if both ATP & NADPH are supplied with CO2 the only product of light reaction required in dark reaction are NADPH & ATP.