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

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 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

Some dinosaurs had feathers, although they could not fy using those feathers. Birds seem to have later adapted the feathers for fight. This means that birds are closely related to reptiles and have evolved from them

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

similarities due to sharing of chromosomes from both the parents variation due to mutuation ,genetic recombination

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

Menopause is a natural process at the age of 40s or 50s in case of human females. Menopause occurs when a women has not have her menstrual cycle for 12 consecutive months and can no longer become pregnant naturally.

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

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.

Small intestine receives Juices from liver, pancreas and walls of small intestine. Bile Juice from liver emulsifes the fats and makes the medium alkaline. Pancreas and small intestine Juices contain amylase, lipase and tryspin

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 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.