Class 10/Specimen Paper
Created by Titas Mallick
Biology Teacher • M.Sc. Botany • B.Ed. • CTET (CBSE) • CISCE Examiner
BioNotesBioNotesCreated by Titas Mallick
Biology Teacher • M.Sc. Botany • B.Ed. • CTET (CBSE) • CISCE Examiner
Online
ICSE Suggested Specimen Paper Based Preparation Guide
An experiment is set up with an aquatic plant (Hydrilla) in a beaker of water under sunlight, and bubbles are observed rising from the plant. What gas are these bubbles composed of, and which specific process in photosynthesis produces this gas?
A leaf from a destarched plant is partially covered with black paper and then exposed to light. When the starch test is performed, only the uncovered parts turn blue-black. What does this experiment prove?
Odd One Out: ATP, NADPH, Oxygen, Glucose.
Scenario: A plant is grown in an atmosphere that is rich in oxygen but has very low levels of carbon dioxide. How will this affect the plant's ability to produce glucose? Explain your answer in the context of the phases of photosynthesis.
The Importance of Rainforests in the Global Carbon Cycle
Tropical rainforests, like the Amazon, are often called the "lungs of the planet." This is because they are home to a vast number of trees and plants that carry out photosynthesis on an enormous scale. Through this process, they absorb massive quantities of carbon dioxide (a major greenhouse gas) from the atmosphere and release oxygen. This makes them a critical carbon sink, helping to regulate global climate. However, widespread deforestation for agriculture and logging is destroying these rainforests. When trees are burned or decompose, the carbon they have stored is released back into the atmosphere as CO₂. This case study highlights the crucial role of photosynthesis on a global scale and how human activities like deforestation can disrupt the carbon cycle, contributing to climate change.
Assertion (A): The light-independent reactions of photosynthesis can occur in the absence of light. Reason (R): The light-independent reactions depend on the products of the light-dependent reactions, namely ATP and NADPH.
(a) Both (A) and (R) are true and (R) is the correct explanation of (A). (b) Both (A) and (R) are true but (R) is not the correct explanation of (A). (c) (A) is true but (R) is false. (d) (A) is false but (R) is true.
Some herbicides work by inhibiting the electron transport chain in the thylakoid membranes of chloroplasts. Why is this an effective way to kill a plant? Trace the consequences of this inhibition on both the light-dependent and light-independent reactions.