CBSE Class X – Science Biology Exam ( Full Syllabus)

All ofsprings of F1 generation were tall with round seeds which shows that both Tallness and round seed are dominant traits. However, new combinations were seen in F2 generation which showed that the tall/ short trait and the round/wrinkled seed trait are independently inherited

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

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).

A species is a group of organisms consisting of similar individuals which can breed Jointly and produce fertile ofspring.

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.

If we dig into the earth and start fnding fossils, the fossils we fnd closer to the surface are more contemporary than the fossils we fnd in deeper layers.

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.

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

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

Cracking of voice in males is due to male hormone testosterone, which is produced after sexual maturation

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.

The process of digestion begins in the mouth. The mouth contains a digestive enzyme, salivary amylase. This enzyme breaks the starch molecules in the food, into maltose. The absence of amylase in the saliva thus afects the breakdown of starch into simpler sugar molecules.

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.

Among the given options, Amoeba (binary fssion), Yeast (budding) and banana (vegetative propagation) reproduce by asexual reproduction whereas dogs reproduce by sexual method.

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.