CBSE Class X – Science Biology Exam ( Full Syllabus)

The Foremost attribute are always supreme. Tallness is a dominant trait as a single copy of ‘T’ is enough to make the plant tall, while two copies have to be ‘t’ for the plant to be short.

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

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

The size of the body is an acquired trait because it depends on nutritional status, health conditions, etc. It can change depending on the Components like availability of less or more food.

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.

Repeated division of an organism to produce many daughter cells simultaneously.

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

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

Organisms look similar because they have similar body designs. As the DNA in the cell nucleus is the information source for making proteins and therefore this information source is changed, different proteins will be made which will lead to altered body designs.

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.

Anaerobic respiration (in absence of oxygen) in yeast is known as fermentation as ethanol (alcohol), carbon dioxide and 2 ATP molecules of energy is produced from glucose

Digestion of food starts in mouth by salivary amylase. From here it enters into the stomach via oesophagus The simpler substances formed by chemical digestion are then absorbed by small intestinal villi.

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 anterior vena cava collects deoxygenated blood from the head, chest, and arms and enters the right atrium while the inferior vena cava collects blood from the lower body regions_x000D__x000D_Left atrium receives oxygenated blood from diferent parts of body while right atrium receives deoxygenated blood from lungs_x000D_Left ventricle pumps oxygenated blood to diferent body parts while right ventricle pumps deoxygenated blood to lungs_x000D_Left atrium transfers oxygenated blood to right ventricle which sends it to diferent body parts_x000D_Right atrium receives deoxygenated blood from diferent parts of the body while left ventricle pumps oxygenated blood to diferent parts of the body