CBSE Class X – Science Biology Exam ( Full Syllabus)

Inheritance from the previous generation provides both a common body design and subtle changes in it due to inaccuracies during DNA copying. However, greater diversity will be generated if sexual reproduction is involved

Radish and carrot represent the correct homologous structures because both have similar design or structure, though both are of different species.

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 cross between RR yy and rr YY seeds will obtain RrYy ofspring which will exhibit round and yellow phenotype, as these traits are the dominant ones.

The tendril of a pea plant and the phylloclade of Opuntia are homologous structures, as they are modifed stems but serve diferent functions in diferent plants.

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

formation of single cell during sexual reproduction by fusion of nuclei of male and female gamates.

Budding in which a bud arises from a particular region on a parent body. And after detaching from the parent body the bud grows into a new independent individual

Bread mould prefers damp/warm conditions with ample nutrient supply, on which air-borne spores land and germinate.

Genes are the unit of heredity DNA that determine genetic characters in an organism.

Unisexual flowers contains only one reproductive organ, either male or female.

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

A nephron is a fltering unit present in kidney. It has diferent parts like Bowman’s capsule, glomerulus and tubular region (Renal tubule). Glucose, amino acids and salts are selectively reabsorbed in tubular region.

Anaerobic respiration (in absence of oxygen) in yeast is known as fermentation as ethanol (alcohol), carbon dioxide and 2 ATP molecules of energy is produced from glucose

Digestion of food starts in mouth by salivary amylase. From here it enters into the stomach via oesophagus The simpler substances formed by chemical digestion are then absorbed by small intestinal villi.

Living organisms are well organised structures; they can have tissues, tissues have cells, cells have smaller components in them, and so on. Living creatures keep repairing and maintaining their structures