The question asks to identify the mode of nutrition where organisms synthesize their own food from simple inorganic substances. We need to evaluate each given option based on its definition of nutrition.
C) Autotrophic. Organisms exhibiting autotrophic nutrition are called autotrophs. They produce their own food using simple inorganic substances. Examples include plants, algae, and some bacteria, which perform photosynthesis or chemosynthesis.
The question asks to identify the essential pigment for photosynthesis in plants. Photosynthesis is the process by which plants convert light energy into chemical energy. This process relies on specific pigments to capture light.
Correct Option: B) Chlorophyll is the essential pigment for photosynthesis because it directly absorbs light energy and initiates the electron transport chain, which is central to the conversion of light energy into chemical energy.
The question asks about the primary mechanism by which antioxidants, found in fresh fruits and vegetables, contribute to health and longevity. This requires understanding the basic biological role of antioxidants in the human body.
C) They neutralize the free radicals produced in the body during metabolism. This is the primary and most well-understood mechanism by which antioxidants exert their beneficial effects. Free radicals are highly reactive molecules that can cause cellular damage, and antioxidants work by stabilizing these radicals, thereby preventing oxidative stress and its associated health problems, including aging and various diseases.
The question asks to identify the tiny pores on leaves responsible for gas exchange. This is a fundamental concept in plant biology, specifically related to photosynthesis and respiration.
C) Stomata
Stomata (singular: stoma) are tiny pores, primarily found on the epidermis of leaves, but also on stems and other organs. They are crucial for gas exchange, allowing carbon dioxide to enter for photosynthesis and oxygen and water vapor (transpiration) to exit. Each stoma is surrounded by two specialized cells called guard cells, which regulate its opening and closing.
The question asks to identify the type of nutritional relationship that Cuscuta (dodder) exhibits, given that it derives its food from other plants. We need to understand the definitions of the terms provided in the options.
B) Parasite — A parasite is an organism that lives on or in a host organism and obtains its food from or at the expense of its host. Cuscuta, also known as dodder, is a parasitic plant that lacks chlorophyll and attaches itself to other plants to absorb water and nutrients, thus harming the host plant.
The question asks to identify which substance is NOT required for photosynthesis. Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize foods with the help of carbon dioxide and water. We need to recall the key inputs and outputs of this biological process.
C) Oxygen — Oxygen is a byproduct of photosynthesis, released into the atmosphere. It is not consumed by the plant during the process of photosynthesis itself.