Karnataka Board Class 10 Biology — Flashcards for Quick Revision

A: DNA (Deoxyribonucleic acid) is the hereditary material that contains genetic instructions. Location pathway: Cell → Nucleus → Chromosome → DNA. It is found in the nucleus of eukaryotic cells, packaged

A: DNA has a double helix structure with two strands. Components: (1) Nucleotide - basic unit containing deoxyribose sugar, phosphate group, and nitrogen base (2) Strands made of sugar-phosphate backbone

A: Four nitrogen bases: Adenine (A), Thymine (T), Guanine (G), Cytosine (C). Base pairing rules: A pairs with T, G pairs with C. This is called complementary base pairing and is held together by hydrogen

A: F.W. Went cut the coleoptile tip of oat plants and placed it in agar. When agar blocks were placed on the cut end, the plant grew upward. When placed on one side, the plant bent toward the opposite si

A: Target cells are specific cells where hormones act. Each hormone's target cell has suitable receptors on the cell membrane or inside the cell. Hormones combine with their receptors to form a hormone-r

A: Auxins move away from light to the shaded side of the stem. There, they combine with hormone receptors and cause cells to elongate. The elongated cells on the shaded side cause the stem to bend toward

A: Lamarckism is the theory proposed by Jean Baptiste Lamarck (1744-1829) known as the 'Theory of Inheritance of Acquired Characters'. Its main principle states that organisms acquire new characteristics

A: Lamarckism was rejected because later scientists proved that acquired characters do not cause changes in the genetic structure of organisms. Only genetic changes can be inherited, not physical changes

A: Charles Darwin (1809-1882) proposed the Theory of Natural Selection. Its five main components are: 1) Over production - organisms produce more offspring than the environment can support, 2) Variations