Mix Test - 2

Pitch is a characteristic of sound that depends upon its frequency.

Objects of different sizes and conditions vibrate at different frequencies to produce sounds of different pitches.

Hence, the correct option is (B).

As we move away from the sun in the solar system time taken by planets to complete one orbit around the sun increases.

The Earth isn't even spiraling in toward the Sun, it's spiraling outward, away from it. So are all the planets of the Solar System. Over the course of a year, Earth moves sometimes closer to the sun and sometimes farther away from the sun. 

Earth's closest approach to the sun, called perihelion, comes in early January and is about 91 million miles (146 million km). The farthest from the sun-earth gets is called aphelion.

Hence, the correct option is (C).

The pupil is the opening in the centre of the iris (the structure that gives our eyes their colour).

The function of the pupil is to allow light to enter the eye so it can be focused on the retina to begin the process of sight. Typically, the pupil appears perfectly round, equal in size and black in colour.

So, The iris controls the light entering in the human eye.

Hence, the correct option is (A).

'Planet have their own source of light' is not associated with planet.

The word ‘planet’ comes from the Greek word “Planetai” which means ‘wanderers’. It is a celestial body that does not have its own light. They depend on Stars for their light and energy. Sun is the source of energy for all of the planets. Planets have sufficient gravity to attract their satellite and the neighbor objects.

Hence, the correct option is (B).

Fertilization results in the formation of a zygote that takes place in the oviduct. This zygote then undergoes a series of changes before it actually gets implanted in the uterus. Zygote first undergoes cleavage and results in the formation of 16 cells known as a morula. This is a solid ball and is represented by figure a. The morula then enters the uterus and undergoes changes. The 16 celled morula further forms 32 cells and these then start arranging in two layers: outer trophoblast and inner embryonal mass. This also forms a cavity and is known as a blastocyst and the structure is known as a blastula. This now gets implanted in the uterus. Thus figure b is a blastocyst.

Hence, the correct option is (A).

The male reproductive system in cockroaches consist of a pair of testes, a pair of vas deferens, ejaculatory duct, seminal vesicle, mushroom glands, and external genitalia. Testes are present at 4th-6th segments while the mushroom gland is present in 6th -7th segments. The female reproductive system consists of a pair of ovaries, a pair of oviducts, a common oviduct i.e., vagina, genital chamber and external genitalia. The genital chamber shows the opening of spermathecae which is a storehouse of sperms. Ovaries extend from 2th - 6th segments and show many tubules known as ovarioles. Spermathecae is in the 6th segment.

Hence, the correct option is (B).

Except for milk other dairy products are produced from the main constituent milk by the process of fermentation. The breakdown of carbon-containing substances like carbohydrates in the absence of oxygen by microorganisms like yeast and bacteria is termed fermentation. Fermentation is involved in making bread, vinegar, yogurt, wine, cider, cocoa, cheese, etc.

Hence, the correct option is (B).

The part of the eye having the largest refractive index is lens. Refractive indices of all materials are a function of the frequency of light. For example, water which has a refractive index of 1.33 at visible frequency has a DC (low frequency) refractive index around 9.

Hence, the correct option is (A).

Rhizobium bacteria fix atmospheric Nitrogen.

Rhizobium–legume symbioses are of great ecological and agronomic importance, due to their ability to fix large amounts of atmospheric nitrogen. These symbioses result in the formation on legume roots of differentiated organs called nodules, in which the bacteria reduce nitrogen into ammonia used by the host plant.

Hence, the correct option is (A).

The process of mitosis can be studied in onion root tip, garlic root tip, tendril tip.

Mitosis is a type of division where a cell is divided in such a manner that the daughter cells receive the exact number of chromosomes as the parent cell. The tips of any plant consist of meristematic cells that are actively dividing cells and produce new cells by mitosis. Thus, root tips of onion and garlic are used as a sample for studying mitosis in the laboratory.

Hence, the correct option is (D).