CBSE Class X – Science Biology Exam ( Full Syllabus)

Hormones and enzymes are proteins, and the formation of any specific protein is controlled by a particular gene. Fat biosynthesis occurs through metabolic reaction.

The maleness of a child is determined by the presence of the Y chromo-some in the zygote inherited from the father.

The pair of sex chromosomes is odd as it is not a perfect pair. Women have a perfect pair of sex chromosomes, both called XX while men have a mismatched pair in which one is a normal sized X and the other is a short one called Y.

The sex of the children will be determined by what they inherit from their father. A child who inherits an X chromosome from her father will be a girl and the one who inherits a Y chromosome from him will be a boy

The reduction in the weight of an organism due to starvation is not genetically controlled as it will not change the DNA of the germ cell.

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.

After the pollen lands on a suitable stigma, a tube grows out of the pollen grain and travels through the style to reach the female ovary.

Flowers are the sexually reproductive organs of a plant and a fertilized flower give rise to fruit

Hepatitis is not a sexually transmitted disease. It is a water-borne viral disease compared to other options.

Reproduction is one of the important characteristic function of living things. it is essential for the continuity of species for generations to continue.

Pancreas secretes pancreatic Juice which contains trypsin, lipase and pancreatic amylase. Trypsin digests the proteins, lipase breaks down the fat droplets already emulsifed by bile salts and pancreatic amylase breaks down the starch.

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.

The oxygen during photosynthesis comes from split water.

Steps of photosynthesis are as follows: (i) Absorption of light energy by chlorophyll. (ii) Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and oxygen. (iii) Reduction of carbon dioxide to carbohydrates.