Science [2 Mark Questions]

No, because geographical barrier do not allow breeding between such individuals of a population which reproduce sexually. Moreover, asexually reproducing organism pass on the parental DNA to offspring which gives no chance of speciation.

Homology, in biology, similarity of the structure, physiology, or development of different species of organisms based upon their descent from a common evolutionary ancestor.
According to Darwin, more closely related species have evolved from a common ancestor. The characteristics and fundamentally similar structures suggest the possibility of a common ancestor.
Such a phenomenon of similarity of structures due to common ancestry is known as homology.

Any change in non-reproductive tissues cannot be passed on to the DNA of the germ cells. Therefore, the traits acquired during life-time on an individual are not inherited.

A monohybrid cross is a breeding experiment between P generation (parental generation) organisms that differ in a single given trait. The P generation organisms are homozygous for the given trait. However, each parent possesses different alleles for that particular trait. A Punnett square may be used to predict the possible genetic outcomes of a monohybrid cross based on probability. This type of genetic analysis can also be performed in a dihybrid cross, a genetic cross between parental generations that differ in two traits.

Layer of fossils get deeper and deeper with the passing time like dinosaurs fossils were found deeper because they die a long time ago. so, fossils which are recent means not very old are present near the surface of earth because they didn't get time to get deeper. therefore this statement is correct Older fossils are found closer to the surface of deep in the Earth strata.

1. Green seed: Yellow is dominant: Green is recessive.
2. Wrinkled seed: round is dominant: wrinkled is recessive.

Geographical isolation cannot be a major factor in the speciation of an asexually reproducing organism because it does not require any other organism to carry out reproduction.

This can be proved with help of Miller and Urey experiment: They took a mixture of ammonia, hydrogen sulfide and and methane and water and provided it a temp. of just below 100 degree Celsius and exposed it to 25000 V electric sparks to resemble the lightning. After 8-10 days 15% of carbon from methane had been converted into organic compounds of sugars, organic acids etc. These had self-duplicating power. So basically life came from inanimate matter.

The wing of a butterfly and the wing of a bat are similar in function. They help the butterfly and the bat in flying. Since they perform similar function, they are analogous organs and not homologous.

1. Give the modern name for this ‘factor’.
2. State where these factors are found in gametes.

A real image can be obtained on the screen. The real image is always inverted. The common example of real image is the image formed on the cinema screen. A virtual image is that image which is formed when the light rays coming from an object do not actually meet, but appear to meet when produced backwards.

Analogous Organs: Organs which performs similar function but are different in structure and origin.
Example: wings of a bird and wings of an insect.
Homologous Organ: Organs which have different functions but similar structure and origin.
Example: fore arm of frog, lizard, bird and human.

1. Tall plant.
2. Dwarf plant.
3. Female.
4. Male.

The presence of analogous organs indicates that even the organisms having organs with different structures can adapt to perform similar functions for their survival under hostile environmental conditions. Thus, the presence of analogous organs in different animals provide evidence for evolution by telling us that though they are not derived from common ancestors, they can still evolve to perform similar functions to survive, flourish and keep on evolving in the prevailing environment.

Analogous structures are structures, such as organs or parts of a plant or animal, that are very similar in two completely unrelated organisms. They occur when the organisms evolve under similar conditions.
Such as penguins and seals both having flippers because they evolved to swim.

The give information is not enough to tell us which of the traits - blood group A or O - is dominant. In blood heredity, blood Type A is always dominant and blood Type O is always recessive.
Here, father’s Blood group can be AA (homozygous) or AO (heterozygous) genotypic ally, where as that of mother can be OA or OO. For daughter to be born with blood group O, she must receive O type gene one each from father and mother. For this father must have heterozygous AO blood group and mother must have homozygous blood group OO.