Bihar STET Paper 1 Science Mock Test - 4 - Bihar PGT/TGT/PRT MCQ

The cerebrum, the large, outer part of the brain, controls reading, thinking, learning, speech , emotions and planned muscle movements like walking.

Cell is kept in hypotonic solution then due to osmosis the solvent particles enter into the cell termed as endosmosis which results in bulging of the cell this state is termed as turgid cell.

To determine the correct chemical formula, we need to analyze each option and identify any errors.
Option A: CaCI
This option is incorrect because it is missing a subscript for the chlorine ion. The correct formula for calcium chloride is CaCl2.
Option B: NaS0₄
This option is incorrect because it contains an incorrect subscript. The correct formula for sodium sulfate is Na2SO4.
Option C: NaS
This option is incorrect because it does not represent a valid compound. It combines sodium (Na) with sulfur (S), but there is no such compound with this formula.
Option D: NaCl
This option is correct. It represents the chemical formula for sodium chloride, which is a common and well-known compound.
Therefore, the correct chemical formula is option D: NaCl.

Key Points:
- The non-metal that is the best conductor of electricity is graphite.
- Graphite is a form of carbon that has a unique structure allowing it to conduct electricity.
- This is due to the presence of delocalized electrons in its structure.
- Delocalized electrons are free to move throughout the material, allowing for the flow of electric current.
- Graphite is commonly used as an electrode material in batteries and fuel cells.
- It is also used in electrical contacts, such as in switches and relays.
- Other non-metals, such as phosphorus, fluorine, and bromine, are not good conductors of electricity.
- Phosphorus is a poor conductor because it is a non-metal and does not have delocalized electrons.
- Fluorine is a non-metal with a very high electronegativity, making it highly reactive and unlikely to conduct electricity.
- Bromine, although it is a liquid at room temperature, is also a poor conductor of electricity due to its non-metallic properties.

Auxin is the plant hormone that is synthesized at the shoot tip and is responsible for promoting cell elongation. It plays a vital role in phototropism, which is the plant's growth response toward light. Auxin helps regulate various aspects of plant growth and development by controlling cell division, differentiation, and elongation.

Leghorn is probably the best egg-laying breed to introduce to tropical Countries, if conditions are not too harsh. Eggs are produced at a lower price and the large comb and wattles, naked legs and white feathers are all factors favouring thermo-tolerance. Where a hot climate and insufficient feeding are limiting factors, Leghorn-derived breeds are more suitable and may also be utilised to improve  the genetic pool of local strains.

Copper doesn't react with dilute sulphuric acid, Liberating hydrogen because copper is lower in the electromotive series than hydrogen. A more reactive element can displace a less reactive element from its salt solution.

Dienes are the name given to compounds with two double bonds.

Chipko Andolan Origin
The Chipko Andolan, also known as the Chipko Movement, originated in a remote village called Reni in Garhwal in the Himalayas during the year 1973. This grassroots environmental movement was aimed at protecting the forests from deforestation and promoting ecological conservation. Here is a detailed explanation of the Chipko Andolan's origin:
Background:
- The Chipko Andolan was a response to the rampant deforestation and commercial logging activities that were threatening the survival of the local communities and their natural resources.
- The region of Garhwal in the Indian state of Uttarakhand was heavily dependent on forests for their livelihood, as they relied on them for firewood, fodder, and other essential resources.
Key Events:
- In 1973, a government contractor arrived in Reni village with a team of workers to fell trees in the nearby forest.
- Amrita Devi, a local woman, along with other women from the village, bravely stood in front of the trees, hugging them to prevent their cutting.
- The women's act of hugging the trees and forming a human chain to protect them gained widespread attention and sparked the Chipko Andolan.
Significance:
- The Chipko Andolan gained momentum as people realized the importance of preserving forests for sustainable development and the well-being of future generations.
- The movement advocated for community-based forest management and raised awareness about the adverse effects of deforestation on the environment, biodiversity, and local communities.
- Chipko Andolan inspired similar environmental movements in other parts of India and across the world, contributing to the development of the concept of ecological activism.
In conclusion, the Chipko Andolan originated in the year 1973 in the remote village of Reni in Garhwal. It was a grassroots movement that aimed to protect forests from deforestation and promote ecological conservation. The courageous act of hugging trees by the local women gained widespread attention and sparked a larger movement for environmental preservation.

Analysis of Mitochondrial Membranes

- Outer Mitochondrial Membrane: The outer mitochondrial membrane is quite porous because of the presence of many integral proteins known as porins. These proteins form channels that allow the free diffusion of molecules and ions up to a certain size, including small proteins.

- Inner Mitochondrial Membrane: The inner mitochondrial membrane is deeply folded, forming structures known as cristae. These folds increase the surface area of the membrane, thereby enhancing the ability of the mitochondria to produce ATP (adenosine triphosphate), which is the energy currency of the cell.

- Length of Membranes: The statement that the outer membrane is longer than the inner membrane is not correct. The length of the membranes is not a distinct feature of mitochondria. Instead, the inner membrane has more surface area due to its folds or cristae.

- Number of Membranes: Mitochondria are double-membraned organelles. They have an outer membrane and an inner membrane, separated by an intermembrane space. The statement that mitochondria mostly have a single membrane is incorrect.

So, based on the analysis, the correct statement regarding mitochondrial membranes is "The outer membrane is porous while the inner membrane is deeply folded".the inner membrane has more curls and turns compared to outer membrane , you can also take reference of brain(it has many curls and turns(neurons) and many experts say that our brains' neurons are much longer in length of our inner intestine(inner intestine measures 7 meters)).

All the Noble gases are placed in the group 18 and all elements are placed in the order of increasing atomic number. Therefore, the elements of atomic number before the Noble gas is placed in the before group of the period of Nobel gas which is group 17.

When a strong acid and a weak base combine to form a salt, the resulting compound will be acidic with a pH less than 7. This is because the presence of a strong acid will dominate the weak base, resulting in an overall acidic compound.

The kidneys are located in the abdominal cavity, one on either side of the backbone.

Nonmetals are present on the right hand side of the periodic table. They are usually solids or gases at room temperature with low melting and boiling points (boron and carbon are exceptions). The only liquid non-metal is bromine. Most non-metals are brittle and are neither malleable nor ductile. 

Hypotonic solutions are the ones which have a lower concentration of solute than the inside the cell. Water diffuses into the cell to balance the solute concentration on either side (outside and inside) equal. Here the cell swells up due to entry of water by endosmosis. 

Non-biodegradable substances:

• Nylon: Nylon is a synthetic polymer that is not easily broken down by natural processes. It takes hundreds of years for nylon to decompose, making it non-biodegradable.

Biodegradable substances:

• Tea leaves: Tea leaves are organic materials that can be easily decomposed by bacteria, fungi, and other microorganisms. They are biodegradable and contribute to the natural nutrient cycle.


• Remains of animals: Animal remains, such as bones and flesh, are also organic materials that can be broken down by natural processes. They are biodegradable and play a role in the decomposition and recycling of nutrients in ecosystems.


• Fleece of sheep: Fleece, which is the wool obtained from sheep, is a natural fiber that can be broken down by microorganisms over time. It is biodegradable and does not contribute to long-term environmental pollution.

In conclusion, the non-biodegradable substance among the given options is nylon. It is a synthetic material that takes a long time to decompose, leading to potential environmental pollution if not properly disposed of.

One significant physical change experienced by girls during puberty is breast enlargement. This is a result of the development of mammary glands and the accumulation of fatty tissue in the breasts. It is a normal part of female sexual maturation and a key characteristic of this phase.

Mendeleev has the foresight to leave some gaps in the periodic table for 3 elements and these elements are discovered later and included in the table.