CBSE Class X – Science Biology Exam ( Full Syllabus)

A single copy of ‘T’ is enough to make the plant tall whereas both copies have to be ‘t’ for the plant to be dwarf. Therefore, Tallness is a dominant trait whereas dwarfness (t) is a recessive trait

Radish and carrot represent the correct homologous structures because both have similar design or structure, though both are of different species.

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.

only one parent is involved in the Asexual reproduction ,there is no fusion of male and female gamates.

Genes are carriers of genetic information and are responsible for the transmission of characteristics from parents to offspring's.

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.

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.

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.

Bile is secreted by the liver and is stored in the gall bladder from where it enters the small intestine via a common duct.

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 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 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.

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