CBSE Class X – Science Biology Exam ( Full Syllabus)

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

The maleness of a child is determined by the presence of the Y chromo-some in the zygote inherited from the father.

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

One of the conclusions of this theory is that the processes of genetic drift—random change in gene frequency—operate in different ways in two isolated population groups and make them more and more different from each other.

Genes are Detected on the chromosomes, which is present inside the nucleus of the cell in the crytoplasm.

Tall plants having round seeds as well as dwarf plants with wrinkled seeds. There were also new combinations like tall plants with wrinkled seeds and dwarf plants with round seeds in the F2 progeny.

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

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

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.

The gametes are reproductive cells. They contain only half the number of chromosomes as compared to the normal cells.

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.

Reproduction is one of the important characteristic function of living things. it is essential for the continuity of species for generations to continue.

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

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

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

Living organisms are well organised structures; they can have tissues, tissues have cells, cells have smaller components in them, and so on. Living creatures keep repairing and maintaining their structures