CBSE Class X – Science Biology Exam ( Full Syllabus)

Sexual reproduction Require exchange of genetic materials of male and female gametes to form

The wings of an insect and a bird have distinct structures but they carry out the same function of fying. Therefore, they are analogous organs

Asexual reproduction will not result in variation as there are no gametes involved. Movement of individuals from one habitat to another will not afect the DNA.

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 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.

In Rhizopus fungus, the fne thread-like structures that spread on the surface of bread are called hyphae

Umbilical cord is responsible for exchange of nutrients, oxygen and waste products between the embryo and the mother’s body .

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

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

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.

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.

During inhalation, the ribs move out and the diaphragm fattens. As a result, the surface area for gaseous exchange increases. The site for gaseous exchange in the lungs are alveoli._x000D_During inhalation, ribs move inward and diaphragm is raised_x000D_In the alveoli, exchange of gases takes place i.e. oxygen form alveolar air difuses into blood and carbon dioxide from blood into alveolar air._x000D_Haemoglobin has greater aǝinity f or carbon dioxide than oxygen_x000D_Alveoli increases surface area for exchange of gase

The oxygen during photosynthesis comes from split water.

The opening and closing of the pore is a function of the guard cells. The guard cells swell when water fows into them, causing the stomatal pore to open. Similarly, the pore closes if the guard cells shrink.