CBSE Class X – Science Biology Exam ( Full Syllabus)

One pair called the sex chromosomes is odd, not always being a perfect pair. Women have a perfect pair mismatched pair, in which one is a normal-sized X while the other is a short one called Y (XY).

The character of the cross will be cross fertilization, which is the transfer of pollen from one plant to the stigma of fower; borne on a distinct plant of the same species.

One of the conclusions of this theory is that the processes of genetic drift—random change in gene frequency—operate in different ways in two isolated population groups and make them more and more different from each other.

The genotype ratio of F2 generation is: TT : Tt : tt = 1 : 2 : 1. Therefore, the ratio of TT and tt plants of F2 generation will be the same. 4. Two pink coloured fowers on crossing resulted

similarities due to sharing of chromosomes from both the parents variation due to mutuation ,genetic recombination

Sexual reproduction involves fertilisation of male and female gametes to produce zygote having genetic variations. Clones cannot be produced through it as clones are identical copies of parent organism.

The gametes are reproductive cells. They contain only half the number of chromosomes as compared to the normal cells.

Bile is secreted by the liver and is stored in the gall bladder from where it enters the small intestine via a common duct.

The lime water turns milky on passing carbon dioxide gas into it due to formation of insoluble calcium carbonate. When the exhaled air rich in carbon dioxide is blown from mouth into test tube, it reacts with lime water (calcium hydroxide) to produce calcium carbonate and water

The anterior vena cava collects deoxygenated blood from the head, chest, and arms and enters the right atrium while the inferior vena cava collects blood from the lower body regions_x000D__x000D_Left atrium receives oxygenated blood from diferent parts of body while right atrium receives deoxygenated blood from lungs_x000D_Left ventricle pumps oxygenated blood to diferent body parts while right ventricle pumps deoxygenated blood to lungs_x000D_Left atrium transfers oxygenated blood to right ventricle which sends it to diferent body parts_x000D_Right atrium receives deoxygenated blood from diferent parts of the body while left ventricle pumps oxygenated blood to diferent parts of the body

The examples and the relation of animal group and heart are as Fishes have two chambered heart and exhibit single circulation while three chambered heart of amphibian and reptiles and four chambered heart of birds and mammals exhibit double circulation.

Xylem tissues include tracheids, vessels, fbres and parenchyma and serve in the ascent of sap/water and minerals.