CBSE Class X – Science Biology Exam ( Full Syllabus)

Acquired traits are the changes which do not occur in the DNA of the individual or in its genes thus they are not passed from one generation.

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.

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

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

Bisexual flowers contains both reproductive organs, male & female.

Valves prevent backward fow of blood as they are located at each end of two ventricles and act as one way inlet.

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.

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.

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

They convert carbon dioxide and water into carbohydrates in the absence of sunlight Explanation: Autotrophs obtain the required carbon and energy requirements from carbon dioxide and Sunlight. They combine carbon dioxide and water to form carbohydrates

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.