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.

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

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.

One pair called the sex chromosomes is odd, not always being a perfect pair. Women have a perfect pair mismatched pair, in which one is a normal-sized X while the other is a short one called Y (XY).

The two versions of a trait which are brought in by the male and female gametes are situated on copies of the same chromosome. Each parent contributes one copy of the gene for a particular trait.

The wings of an insect and a bird have distinct structures but they carry out the same function of fying. Therefore, they are analogous organs

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.

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

Sexual reproduction involves fertilisation of male and female gametes to produce zygote having genetic variations. Clones cannot be produced through it as clones are identical copies of parent organism.

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.

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

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

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.

The oxygen during photosynthesis comes from split water.

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.