Biology MCQs

Notes:
Heart disease and High blood pressure are examples of Multifactorial Genetic Inheritance. It is also known as polygenic inheritance.

Notes:
Insulin is central to regulating carbohydrate and fat metabolism in the body. It stops the use of fat as an energy source by inhibiting the release of glucagon. It removes excess glucose from the blood, which otherwise would be toxic. Insulin helps blood sugar enter the body’s cells so it can be used for energy. Insulin also signals the liver to store blood sugar for later use. Blood sugar enters cells, and levels in the bloodstream decrease, signaling insulin to decrease too.

Notes:
Sexual reproduction in Aspergillus is rare and takes place in favourable conditions. Sex organs are produced on the same mycelium which has produced conidia. Male organs are called Antheridium or Pollinoduim and female are called archicarp or Ascogonium. Female organs develop as a branch of hypha. The antheridium curves round and bend towards the apex of archicarp as a result of which they become spirally coiled and their tips get fused.

Notes:
During hibernation in winter, toads or frogs spend the time tucked away deep in the soil, in the mud underwater or hidden amidst foliage or rotting plants. Outside of times of hibernation, they usually take in oxygen via the air, employing their lungs. However, during hibernation, they receive their necessary oxygen through their permeable skin. This is referred to as cutaneous gas exchange.

Notes:
Plant wilting occurs after excessive loss of water by transpiration and lesser absorption. i.e. rate of transpiration exceeds rate of water absorption. On a hot day, plants transpire heavily and cannot absorb water speedily to keep pace with transpiration loss, even when there is enough water.

Notes:
The skin is the soft outer covering of vertebrates that guards the underlying muscles, bones, ligaments, and internal organs. The cutaneous membrane is the technical term for our skin. The skin’s primary role is to help protect the rest of the body’s tissues and organs from physical damage such as abrasions, chemical damage such as detergents, and biological damage from micro organisms. Our skin is made of three general layers. In order from most superficial to deepest they are the epidermis, dermis, and subcutaneous tissue.

Notes:
Feed cost is one of the important variable costs that plays a big role in determining the poultry cost. Variable costs rise and fall with the size of the output and the level of the operation. Fixed costs (for items such as taxes, insurance, interest, and depreciation on buildings and equipment), are incurred whether or not there is any output. Moreover the feed of broilers and layers varies with time of their growth.

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The human brain sends messages to other parts of the body through a network of connecting wires (neurons) called the nervous system. Neurons carry messages in the form of electrical signals called nerve impulses. The human brain contains about 100 billion neurons.

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Wolffia is a genus of 9 to 11 species which include the smallest flowering plants on Earth. Commonly called water-meal or duckweed, these aquatic plants resemble specks of cornmeal floating on the water. Wolffia species are free-floating thalli, green or yellow-green, and without roots. The flower is produced in a depression on the top surface of the plant body. It has one stamen and one pistil.

Notes:
The Malabar Grey Hornbill is a hornbill that is endemic to the Western Ghats and associated hills of southern India. They are found mainly in dense forest and around rubber or coffee plantations.