The question asks to identify the Indian state where unique 'living root bridges' are found. This is a general knowledge question related to the geography and unique cultural practices of different regions in India.
A) Meghalaya is the correct answer. The living root bridges are a unique cultural and ecological marvel found in the state of Meghalaya, particularly in areas inhabited by the Khasi and Jaintia tribes. These bridges are a testament to indigenous bioengineering and sustainable practices.
The question asks about the most effective light colors for photosynthesis. This requires knowledge of the absorption spectrum of photosynthetic pigments, primarily chlorophyll a and b.
C) Red and Blue — Chlorophylls (chlorophyll a and b) absorb light most strongly in the blue-violet and red regions of the visible spectrum. These absorbed wavelengths provide the energy for photosynthesis, making them the most effective colors.
The question asks about the effect of ultraviolet (UV) light on plant growth. To answer this, we need to recall the general biological responses of plants to different types of light, specifically UV radiation.
C) Plants become dwarf. Excessive ultraviolet light, particularly UV-B, acts as a stress factor for plants. In response to this stress, plants tend to inhibit cell elongation and division, leading to reduced overall growth and a more compact, dwarfed stature. They also invest energy in producing protective pigments, which diverts resources from growth.
'Die back' in plants is a condition where branches or shoots die progressively from the tip downwards. This phenomenon is rarely caused by a single factor but rather by a combination of environmental stresses and biological agents that weaken the plant's defense mechanisms.
Correct Option: C) A combination of factors including frost and drought. This option correctly identifies that die back is typically a result of multiple interacting factors, with environmental stresses like frost and drought being significant contributors. Other factors like nutrient deficiencies, disease, and insect damage can also be involved.
The question asks to identify an active insectivorous plant from the given options. Insectivorous plants are broadly classified into active and passive types based on their trapping mechanism. Active traps involve rapid movement to capture prey, while passive traps rely on static structures.
Utricularia, commonly known as bladderworts, are active insectivorous plants. They possess highly specialized bladder traps that create a vacuum. When an aquatic insect or larva touches trigger hairs near the bladder opening, the trapdoor rapidly opens, sucking in water and the prey in milliseconds. This is a classic example of an active trapping mechanism involving rapid movement.
The question asks us to identify the correct statements regarding vegetative propagation in plants. We need to evaluate each statement based on the principles of plant reproduction and horticulture.
Vegetative propagation is a form of asexual reproduction where new plants are produced from vegetative parts of the parent plant (like stems, roots, or leaves). Since there is no fusion of gametes, the offspring are genetically identical to the parent plant. This group of genetically identical individuals is known as a clone. Therefore, this statement is correct.
Vegetative propagation itself does not eliminate viruses from an infected plant. If the parent plant is infected with a virus, the vegetatively propagated offspring will also be infected. However, specific techniques like meristem culture (a type of tissue culture, which is a form of vegetative propagation) can sometimes produce virus-free plants because the meristematic tissues are often free of viruses even in an infected plant. But vegetative propagation in general does not guarantee virus elimination. Therefore, this statement is generally incorrect in its broad sense.
Many vegetative propagation methods, such as cuttings, layering, and grafting, can be performed throughout a significant portion of the year, especially in controlled environments or during favorable seasons. Unlike sexual reproduction which is often tied to specific flowering seasons, vegetative methods offer more flexibility. For example, tissue culture can be done year-round. Therefore, this statement is correct.
Based on the analysis, statements 1 and 3 are correct.
Correct Option: C) 1 and 3 only