CBSE Class X – Science Biology Exam ( Full Syllabus)

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

The two versions of a trait which are brought in by the male and female gametes are situated on copies of the same chromosome. Each parent contributes one copy of the gene for a particular trait.

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 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

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

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

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

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

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.

Pseudopodia are developed in amoeba. Amoeba engulfs its food particles by forming pseudopodia around it. The food particle gets surrounded by encircling pseudopodia’s tips.

Rice water contains starch, hence when iodine solution is added to rice water it turns blue-black.

During inhalation, the air is drawn through the nostrils into the nasal passage. From there, air enters into pharynx, larynx, trachea (windpipe), bronchi, lungs and fnally to the alveoli.

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.