OSSC TGT OSSSC Science CBZ Mock Test - 7 Free Online Test 2026

Piaget's theory states that children actively construct their understanding of the world and go through four stages of cognitive development.

A student of any class having a problem of  'visual deficiency' should be treated normally within the classroom and provided support through audio CDs. Children suffering from 'visual deficiency are unable to see, in that case, they should be provided adequate support through audio lectures so that they also gain the same level of understanding as other students.
Hence, the correct answer is, 'Treated normally in the classroom and provided support through audio CDs.'

A teacher should possess some qualities to teach at the primary level such as she should have the patience to deal with all sorts of questions arising in the minds of the students. Students at the primary level ask very silly questions she should not get frustrated with them and reply in a very calm manner. Apart from this, a teacher should also have a quality of perseverance she should stick to her plans and not lose hopes even if she is facing many difficulties in achieving them.
Hence, the correct answer is, 'Patience and Perseverance.'

A teacher having a democratic nature permits students to sit all over the class in which some sit together and discuss or do group reading. Some sit quietly and read themselves. If a parent does not like this behaviour of a teacher then they should show trust in the teacher and discuss the problem with the teacher. Maybe the teacher is doing this with positive hidden motives.
Hence, the correct answer is, 'Parents should show trust in the teacher and discuss the problem with the teacher.'

Adolescence is the stage when children become active members of the peer group. It is a transitional stage of growth and development that lies between childhood and adulthood. According to the World Health Organization, this period occurs between the age of 10 and 19. At this stage, children are more actively involved in their peer group. They share everything with their friends instead of family. They are more comfortable with their peers.
Hence, the correct answer is, 'Adolescence.'

Red algae often serve as a food source for aquatic animals. Many species of marine algae, including red algae, are consumed by various marine organisms, forming the basis of aquatic food chains.

Chlorophyll is a specialised light absorbing pigment which is found in the inner wall of granum. Each granum is a flat, sac-like structure in which light reaction of photosynthesis takes place.

Chloroplasts are photosynthesizing organelles, at which photosynthetic pigment chlorophyll captures, transforms and stores the energy from sunlight in the energy storage molecules NADPH and ATP while liberating oxygen from water in algal and plant cells. In a process referred to as the Calvin cycle, they use the ATP and NADPH to produce organic compounds from carbon dioxide.

Now, let us find the solution from the options-
- In the thylakoid membranes of the organelle, the chloroplast is a plastid containing chlorophyll (green pigment).
- Thylakoid can be described within the chloroplasts of a plant cell as a membrane-bound compartment.
-It is the area of photosynthesis light-dependent reactions.
- Thylakoid comprises a membrane of thylakoid containing thylakoid lumen.
-A load of thylakoid or lamella discs is known as grana.

Thus, the correct answer is option (A) Grana.

Note: At least 3 membrane systems are available for all chloroplasts: the outer chloroplast membrane, the thylakoid system, and the inner chloroplast membrane. There may be extra membranes encircling these three chloroplasts which are the product of secondary endosymbiosis.

Quantum yield is the number of Oxygen molecules released per photon or quantum of light. During light reaction of photosynthesis oxygen molecules are release during photolysis.

Xanthophylls are yellow coloured carotenoids also called xanthols or carotenols.

The work of Melvin Calvin is the discovery that the first CO₂ fixation product was a 3-carbon organic acid. He also contributed to working out the complete biosynthetic pathway; hence it was called the Calvin cycle.

In plants, growth can refer to change in size, it is restricted to meristematic regions of the plant and cannot be reversed.

Green algae usually have a rigid cell wall made of cellulose.

Large amount of fossilized pollen grain are found during excavation process of older parts due to tough covering of Sporopollenin that make the outer wall of pollen grain, exine. This substance cannot be hydrolyzed by any enzyme known.

• At a constant temperature, soil moisture content shows a parabolic affect on decomposition rates with a maximum rate at intermediate levels of moisture.
• High moisture content limits soil gas exchange leading to low oxygen concentrations and potentially anaerobic conditions.
• At low moisture content, the lack of water limits microbial metabolism; however, many microorganisms can remain active to much lower soil water potentials (at -3.0 MPa) than plants (at -1.5 MPa).

Species are organisms with similar characteristics and their inbreeding results in the production of fertile offspring.

Animals use seasonal variations in light intensity and photoperiod to time various activities. Birds of colder areas of northern hemisphere begin their southward migration as the day lengths begin to shorten. Reverse journey is undertaken with the increase in day length. Turkeys, ferrets and starlings breed in response to lengthening of days while goat, sheep and deer breed in response to shortening of days. Rabbits and guinea pigs are day neutral. In temperate and subtropical areas, cold blooded or ectothermic animals undertake hibernation as the day length begins to shorten.

Menstrual flow occurs due to shedding of the endometrium, which is the inner lining of the uterus.

Satellite tobacco necrosis virus (STNV), the first plant satellite virus, was discovered as a virus-like particle abundantly present in cultured medium of tobacco necrosis virus (TNV), a host virus. Its identity as a satellite virus was revealed by its dependence on TNV for propagation.

In angiosperms, endosperm is a triploid structure.
∴ 3n = 24 (given), then n = 8
As gametes are haploid structures, therefore number of chromosomes in gametes is 8

• Zygote undergoes cleavage producing an exponential increase in cell mass.
• These new daughter cells formed are called blastomeres.
• They form a blastula with a blastocoel cavity enclosed in between.

Fluid-Mosaic model is the most recent and accepted model of plasma membrane. This model was proposed by Singer and Nicolson in 1972. The quasi-fluid nature of lipid enables lateral movement of proteinswhithin the overall bilayer.

Triangular age pyramid has high proportion of reproductive individuals, moderate number of reproductive individuals and fewer post-reproductive individuals. It represents young or rapidly growing population.

In urn-shaped age pyramid, the number of reproductive individuals is higher than the number of pre-reproductive individuals. It represents declining or diminishing population with negative growth

In bell-shaped age pyramid, the number of pre-reproductive and reproductive individuals is almost equal. Post reproductive individuals are comparatively fewer. It represents stable or stationary population where growth rate is nearly zero.

Number of moles = Mass (in grams) / Molar mass.

Mendeleev missed receiving the Nobel Prize by one vote. Some atomic numbers of elements on the table were refined and corrected. Elements such as sulfur and hydrogen were difficult to place within the structure of the table but Mendeleev was able to construct the table around anomalous elements.

A compound is a substance formed when two or more elements are chemically joined. Water, salt, and sugar are examples of compounds. When the elements are joined, the atoms lose their individual properties and have different properties from the elements they are composed of.

Stainless steel

Brass

Air

Smoke

The turning of any liquid into vapour is called Evaporation. The factors affecting the evaporation are:

1. Temperature. As the temperature increases, the rate of evaporation also increases.

2. Surface Area. As the Surface area increases, the rate of evaporation increases.

At no. of elements a,b,c,d,e are 2,3,7,10,30. Elements b , c , d belongs to the same period because the no. of valence shells are all 2. Elements B (Li), C (N) and D (Ne) belong to the same group.

Correct Option is D.
Rutherford Model of an atom:
On the basis of Rutherford's experiment,
(1) An atom consist of positively charged, dense and very small nucleus containing protons and neutrons. The entire mass of an atom is concentrated in the nucleus.

(2) The nucleus is surrounded by negatively charged electrons. The electrons are revolving around the nucleus in circular paths at very high speed. These circular paths of the electrons are called orbits.

(3) An atom is electrically neutral because the number of protons and electrons is equal.