Class-vll Periodic Test-1 Subject-science

Explanation
Amarbel is an example of a parasite. A parasite is an organism that lives in or on another organism (host) and derives its nourishment from the host's body. Amarbel is a parasitic plant that attaches itself to the host plant and derives nutrients and water from it.

Explanation
Ruminants have a unique digestive system that allows them to extract nutrients from plant material efficiently. After initially swallowing their food, it goes into the rumen, the largest chamber of their stomach. In the rumen, the food undergoes fermentation by bacteria and other microorganisms. The partially digested food, known as cud, is then regurgitated back into the mouth where it is thoroughly chewed and mixed with saliva. This process, called rumination, allows the ruminant to further break down the food and extract as many nutrients as possible before it continues through the rest of the digestive system. Therefore, the correct answer is Cud.

Explanation
Amoeba uses pseudopodia as its locomotory organ. Pseudopodia are temporary extensions of the cell membrane that help in movement. They are formed by the cytoplasm flowing in a particular direction, creating finger-like projections. Amoeba extends its pseudopodia in the direction it wants to move and then pulls the rest of its body towards it. This allows the amoeba to change its shape and move in any direction. Cilia, flagella, and tentacles are not locomotory organs in amoeba.

Explanation
The sun is the ultimate source of energy for all living beings because it provides light and heat which are necessary for photosynthesis. Photosynthesis is the process by which plants convert sunlight into chemical energy in the form of glucose. This energy is then transferred through the food chain as organisms consume plants or other organisms. Without the sun, photosynthesis would not occur, and there would be no energy available for living beings.

Explanation
The correct answer is "Cell". A cell is the basic structural, fundamental, and functional unit of an organism. It is the smallest unit of life that can perform all the necessary functions for the organism to survive and carry out its activities. Cells are responsible for various processes such as growth, reproduction, and metabolism. They can exist as single-celled organisms or as part of a multicellular organism, where they work together to form tissues, organs, and organ systems. Overall, cells play a crucial role in maintaining the overall structure and function of an organism.

Explanation
Lichens are a symbiotic organism formed by the mutualistic association between a fungus and an alga or a cyanobacterium. The fungus provides a protected environment and absorbs nutrients, while the alga or cyanobacterium photosynthesizes and provides food for both partners. This symbiotic relationship allows lichens to survive in harsh environments where neither the fungus nor the alga/cyanobacterium could survive alone. Therefore, lichens are an example of symbiotic heterotrophic nutrition.

Explanation
The thyroid gland is not a digestive gland. It is an endocrine gland that produces hormones that regulate metabolism. The liver, pancreas, and salivary glands are all involved in the process of digestion. The liver produces bile, which helps in the breakdown of fats. The pancreas produces digestive enzymes that break down carbohydrates, proteins, and fats. The salivary glands produce saliva, which contains enzymes that begin the digestion of carbohydrates in the mouth.

Explanation
Absorption and assimilation take place in the small intestine. This is because the small intestine is responsible for the majority of nutrient absorption in the digestive system. The inner lining of the small intestine is covered in tiny finger-like projections called villi, which increase the surface area available for absorption. These villi contain specialized cells that absorb nutrients such as carbohydrates, proteins, and fats from the digested food and transport them into the bloodstream for distribution to the body's cells. Therefore, the small intestine is the primary site for absorption and assimilation of nutrients in the alimentary canal.

Explanation
Canines are the type of teeth responsible for piercing and tearing food. They have long, sharp points that enable them to grip and tear through tough food items such as meat. Canines are located at the corners of the mouth and are well-suited for tearing apart prey or ripping off pieces of food. Incisors are used for cutting, molars and premolars are used for grinding and chewing, but it is the canines that are specifically designed for piercing and tearing.

Explanation
Cellulose is the correct answer because it is a type of carbohydrate found in grass that cannot be digested by the human digestive system. Unlike glucose, maltose, and sucrose, cellulose cannot be broken down by the enzymes in our body, making it indigestible. This is why humans are unable to derive any nutritional value from cellulose-rich foods like grass.