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

Hormones and enzymes are proteins, and the formation of any specific protein is controlled by a particular gene. Fat biosynthesis occurs through metabolic reaction.

The character of the cross will be cross fertilization, which is the transfer of pollen from one plant to the stigma of fower; borne on a distinct plant of the same species.

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

The cross between RR yy and rr YY seeds will obtain RrYy ofspring which will exhibit round and yellow phenotype, as these traits are the dominant ones.

The reduction in the weight of an organism due to starvation is not genetically controlled as it will not change the DNA of the germ cell.

The genotype ratio of F2 generation is: TT : Tt : tt = 1 : 2 : 1. Therefore, the ratio of TT and tt plants of F2 generation will be the same. 4. Two pink coloured fowers on crossing resulted

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

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

Umbilical cord is responsible for exchange of nutrients, oxygen and waste products between the embryo and the mother’s body .

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

Rice water contains starch, hence when iodine solution is added to rice water it turns blue-black.

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.

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

The oxygen during photosynthesis comes from split water.

Fishes have only two chambers to their hearts, and the blood is pumped to the gills, is oxygenated there, and passes directly to the rest of the body. Thus, blood goes only once through the heart in the fsh during one cycle of passage through 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