MPTET Varg 2 Science Mock Test - 4 - MPTET MCQ

The correct answer is "he wanted to give another opportunity to the boy.”Key Points

• Option 1 is directly supported by the text: "He controlled himself, and asked again : 'How Much ?' as a last chance." This indicates that the teacher controlled his anger to offer the boy another chance to answer. There's a clear link between the teacher's action (controlling himself) and his intention (giving the boy one more chance), which makes Option 1 the more accurate answer.
• Options 2, 3, and 4 are incorrect because there isn't sufficient supportive information in the passage to consider them to be the right answers.

Hence, the correct answer is "The teacher controlled his anger because he wanted to give another opportunity to the boy."

Confusion Points

• Option 2 suggests that the teacher controlled his anger because he remembered the fond hopes of the boy's parents, who wanted their son to be promoted to the first form. Although the parents' expectations are mentioned in the passage, the context surrounding the mention of those expectations is the teacher's perplexity or frustration regarding how the boy could meet these expectations if he's persistently providing a wrong response. The tone seems more exasperated than understanding.
• Moreover, the controlling of the teacher's anger and the recounting of the parents' hopes are not directly linked in the passage. He seems to be considering the parents' hopes as an added complexity to the problem, not as a motivator for patience.

Given:

Quant = 38 %

All Subjects = 100 %

Calculation:

All others subjects = 100% - 38 %

⇒ 62 %

The ratio of Quant and all other students = 38% : 62%

⇒ 19 : 31

The ratio of Quant and all other students = 19 : 31

E. L. Thorndike, an American psychologist, is known as the founder of modern educational psychology.

• He propounded 'Trial and Error Theory' which represents that learning is the result of associations forming between stimulus and responses.
• "Mistakes teaches individual" statement is based on 'Trial and Error Theory'.

Key Points

Thorndike's Experiment:

• Thorndike formulated his theory, base on his experiments conducted on his cat in the puzzle box.
• The door of the box could be opened by pulling the strings inside the box. A fish was kept outside.
• The cat was tried to come out of the box by squeezing, jumping, biting, etc.
• As the experiment was repeated several times the wrong movements decreased and in the end, the cat was able to open the door in a single trail.

Important Points

Based on Trial and Error Learning Theory, Thorndike gave three primary laws of Learning:

• Law of readiness: It refers to the degree of eagerness and inquisitiveness to learn something new.
• Law of exercise: It is based on practice and drill to learn something for a long period.
• Law of effect: It is based on motivation and reinforcement to make learning experience pleasant for learners.

Hence, it becomes clear that  the above-mentioned statement is based on Trial and Error Theory.

Additional Information

• Insightful learning: It emphasizes a sudden solution to the problem as insight doesn't rely on behavior or observation.
• Instrumental conditioning: It is also known as Type R conditioning as the creature release response and gets a reinforcement. This conditioning strength is determined by the number of responses released i.e. response rate.

Gender refers to the socially constructed differences between men and women. It refers to the masculine and feminine qualities, behavior, roles, and responsibilities that society upholds. Gender can be changed / re-oriented.

A stereotype is a simplified and/or standardized conception or image with specific meaning, often held in common by people about another group. A stereotype can be a conventional and oversimplified conception, opinion, or image, based on the assumption that there are attributes that members of the other group hold in common.

Gender stereotype is an oversimplified and unfair belief or idea that groups of people have particular characteristics or that all people in a group are the same.

Key Points 
Gender stereotypes can be reduced by-

• Treating the girls and the boys equally.
• Gave the same and equal opportunity to all the students without making any difference between them.
• Promoting flexibility in the classroom.
• Presenting Non-stereotypical sex roles, such as a girl riding the bike, or a boy cooking in a kitchen.
• Engagement of every student in all the activities without distinguishing them.
• The sitting arrangement of all the boys and girls should not be separated.
• So that we can conclude that gender stereotypes can be reduced by using all these references.

Additional Information

• Gender stereotyping can limit the development of the natural talents and abilities of girls and boys, women and men, as well as their educational and professional experiences and life opportunities in general.
• Stereotypes about women result from deeply ingrained attitudes, values, norms, and prejudices against women.
• To avoid the situation of gender stereotype, a family should start involving boys in household chores that were mainly concerned with girls traditionally which gave rise to gender biasing and stereotyping.

Concept:

• Cells are the structural & functional unit of life.
• Based on the absence or presence of membrane-bound nuclei, cells can be divided into two types - Prokaryotic cells & Eukaryotic cells.
• Eukaryotic cells - The eukaryotic cells are characterised by the presence of a membrane-bound nucleus. 
• Besides the nucleus, the eukaryotic cells have other membrane-bound distinct structures called organelles like the endoplasmic reticulum (ER), the Golgi complex, lysosomes, mitochondria, microbodies and vacuoles.
• Eukaryotic cells are further classified into two types - Animal cells and plant cells.

Explanation:

• Plant and animal cells are different as the former possess cell walls, plastids and a large central vacuole which are absent in animal cells.
• The large vacuole occupies about 90% of the space in the plant cells, due to which the nucleus is pushed to the periphery.
• The vacuole is generally absent in animal cells or if present then it is very small. Animal cells have the nucleus located in the centre.

​

The diagram clearly showing the position of the nucleus in animal & plant cell

Additional Information

Basic characteristics of a typical nucleus - 

• It is an important component of the living cell.
• It is generally spherical and located in the centre of the cell.
• It can be stained and seen easily with the help of a microscope.
• The nucleus is separated from the cytoplasm by a membrane called the nuclear membrane.
• This membrane is also porous and allows the movement of materials between the cytoplasm and the inside of the nucleus.
• The nucleus has small spherical bodies called the nucleolus.
• In addition, the nucleus contains thread-like structures called chromosomes.
• These carry genes and help in the inheritance or transfer of characters from the parents to the offspring.

CONCEPT:

• Work-energy theorem: It states that the sum of work done by all the forces acting on a body is equal to the change in the kinetic energy of the body i.e.,

Work done by all the forces = Kf - Ki

Where v = final velocity, u = initial velocity and m = mass of the body

EXPLANATION:

Given that:

• Mass of the Object (m) = 1 kg
• Initial velocity of the object (u) = 4m/s
• Final velocity of the object (v) = 8m/s
• Total net work is done W _(net) = Kinetic energy (During final velocity) – Kinetic Energy (During Initial Velocity).
• Now by substituting the values in the above equation, we get

W_(net) = ½ mv² – ½ mu²

= ½ (1)×(8)² – ½ (1)×(4)²

= 32 - 8 Joule

= 24 Joules.

• Therefore, the total work done by the force is 24 J.

Correct option is 4  .

• Dalton's atomic hypothesis, which serves as the foundation for contemporary chemistry, is still mostly accurate despite these flaws. 

  The ability to view the world at the atomic level has even been achieved by scientists!

•  Atomic hypothesis of Dalton's four conclusions:

• Atoms make up all matter.
• Atoms are unbreakable and undividable.
•  Two or more different types of atoms combine to create compounds.
•  Atoms are rearranged during a chemical process.

Explanation:

1.  Dalton's theory postulates that the net mass of the involved species in a chemical process is preserved since it asserts that atoms cannot be formed or destroyed. As a result, this postulate explains how the law of conservation of mass works.
2. If two elements combine to form more than one compound, the Law of Multiple Proportions states that the mass ratios of the second element that mix with a fixed mass of the first element will always be ratios of tiny whole integers. This rule, also called Dalton's Law or Dalton's Law of Multiples.
3. Dalton based his hypothesis on the laws of mass conservation and constant composition. All matter is made up of indivisible atoms, according to the first component of his theory. 

   The second aspect of the theory states that the mass and properties of every atom in a particular element are the same.

Concept-

• Cartilage could be a robust, clear, elastic, versatile animal tissue consisting of animal tissue cells scattered through a conjugated protein material that's strong by scleroprotein fibres.
• There aren't any nerves or blood vessels in animal tissue, that are found within the joints, the skeletal structure, the ear, the nose, the throat, and between bone disks.
• The main purpose of animal tissue is to produce a framework on that bone deposition could begin.
• Another vital purpose of animal tissue is to hide the surfaces of joints, permitting bones to slip over each other, therefore reducing friction and preventing damage; it additionally acts as a cushion.
• Classification- Hyaline cartilage, elastic cartilage, and fibrocartilage.

Explanation-

• Elastic Cartilage- Elastic animal tissue is found within the pinna of the ear and several other tubes, like the walls of the modality and eustachian canals and vocal organ.
• Elastic animal tissue is comparable to cartilage however contains elastic bundles (elastin) scattered throughout the matrix.
• This provides a tissue that's stiff nonetheless elastic.
• In the matrix of this cartilage yellow fibres form the network so it is highly flexible cartilage of the body.

Thereby elastic cartilage can be seen in the pinnae of mammals.

Additional Information

• Hyaline Cartilage- It is the most well-endowed form of cartilage. cartilage is found lining bones in joints (articular cartilage). It's additionally gifted within bones, serving as a centre of ossification or bone growth. Additionally, cartilage forms the embryonic skeleton.
• Fibrocartilage- Cartilage could be a specialized form of animal tissue found in areas requiring robust support or nice durability, like between bone disks, at the bone and different symphyses, and at sites connecting tendons or ligaments to bones.

Concept:

Oxidation:

It is the process in which an atom, molecule, or ion loses one or more electrons.

Reduction:

It is the process in which an atom, molecule, or ion gains one or more electrons.

Reducing agent/ Reductant:

• It is one that donates electrons to a species and thereby brings about its reduction.
• The reducing agent is oxidized by having its electrons taken away.
• Eg: In the reaction , the oxidizing agent is MnO2 and the reducing agent is HCl.

Oxidizing agent/ Oxidizer:

• It is defined as a substance that removes electrons from another reactant in a redox chemical reaction.
• The oxidizing agent is reduced by taking electrons onto itself.
• In the reaction , the oxidizing agent is O2 and the reducing agent is Mg.

Explanation:

• As the electronegativity of a species increases, its tendency to pull electrons also increases and eventually behaves as a stronger oxidizing agent.
• Greater the reduction potential, greater will be the tendency of oxidizing agent to get reduced easily and hence acts as a stronger oxidizing agent.

H₂O₂:

• Hydrogen peroxide acts as an oxidizing agent and reducing agent.
• Eg: of reaction in which H₂O₂ acts as an oxidizing agent is as follows: 

O₃:

• Ozone is a strong oxidizing agent.
• It can easily lose nascent oxygen.
• An example of a reaction in which O₃ acting as an oxidizing agent is: 

K₂Cr₂O₇:

• It acts as an oxidizing agent in an acidic medium and can oxidize reducing agents like ferrous sulfate, nitrite, sulfite, etc.
• In these reactions in acid solution, dichromate is reduced to green Cr³⁺ ions: 

KMnO₄:​

• It dissolves in water to give an intensely purple solution.
• KMnO₄ is stronger than any other oxidizing agent because it contains Mn in its highest oxidation state +7.
• Elements become more electronegative as the oxidation state of their atoms is increased.
• Their reaction is as follows: 

The increasing order of reduction potential of the given oxidizing agent is: 

Hence, the increasing order of power of the oxidizing agent is : 

Therefore, ozone is the strongest oxidizing agent.

The correct answer is 4C.

Key Points

• Work is done when a force is applied to a body and makes a body move i.e. when the body displaces from its position by the act of force.
  • For example- Pushing a car horizontally from a rest, Walking upstairs, Shooting a Bullet, etc.
  • Its S.I. Unit is Joule (J).
• The potential difference is the amount of work done by the positive test charge from one point to another point.
  • For example- the movement of free electrons in a metallic conductor.
  • Its S.I. Unit is Volt (V).
• Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field.
  • They are of two types: positive and negative.
  • Its S.I. unit is Coulomb (C).​

Concept

​Work done = Potential Difference × Charge.

Calculation:​

Work- 40 J,

Potential difference- 10 V,

Charge-?

​By Formula,

Work = potential difference × charge 

Charge = work / potential difference

Charge = 40 J / 10 V 

Charge = 4 Coulomb.

Explanation:- 

• Chemical Equation:- Chemical Equation is the symbolic representation of the chemical change or chemical reaction which have taken place.
• The Law of Conservation of Mass states Mass of a matter can neither be created nor destroyed in a chemical reaction and that it is always conserved, which means the total mass of the elements present in the reactants of a chemical reaction has to be equal to the total mass of the elements present in the products.
• Balanced Chemical Reaction:- A chemical equation is balanced if the total no of elements present in the reactant side is always equal to that of the product side. Equations must always be balanced according to mass.

Reaction:-

C₃H₈ + 5 O₂   → 3CO₂ + 4 H₂O

Environmental Studies or EVS is the study of the environment in the context of the earth and living things. 

• At the primary level, children must be taught through an integrated approach rather than teaching in parts. At the primary level, we shouldn't teach students the concepts in isolation.

Key Points

At the upper primary level, the objective of science education can are:

• Acquire the skills and understanding of the processes of the scientific method that lead to the generation and validation of scientific knowledge.
• Inculcating the values of co-operation and concern for life.
• Relate education to the environment.
• Acquire the required theoretical knowledge and practical technical skills to enter the world of work.
• Nurture the natural curiosity.
• Aesthetic sense and creativity in technology.
• Imbibe moral values like honesty, integrity, cooperation, concern for life, and preservation of the environment.
• Instead of emphasizing the definitions, the scientific temper of the students should be cultivated – objectivity, skepticism, critical thinking, and freedom from fear and prejudice.

Hint 

• Emphasizing the textbook definitions of concepts, should not be an objective of science education as the focus should be laid on the practical learning of students so that they will be able to apply the learned concepts in real life.

Hence, it is concluded that emphasizing the textbook definitions of concepts should not be an objective of science education at the upper primary level.

The competency-based teaching method permits students to boost based on their capacity to master a talent or competency at their very own pace no matter their surroundings. This approach is suitable to meet different learning abilities and can lead to more efficient student outcomes.

Important Points

Some of the primary characteristics of competency-based education are :

• Students learn at their very own pace
• Flexibility
• Personalized manner of teaching
• Timely aid
• Purpose-pushed
• A novelty in the evaluation and grading
• A specific strategy for communicating progress
• A talent-based education application that ensures quality
• Affordability
• Peer assistance

Therefore, alternative (a), the students practicing the multiplication table chart isn't suitable right here.

Additional Information

The usefulness of Competency-Based Approach:

• The competency-based approach keeps the learner away from rote memorization.
• What the students learn today cannot be forgotten tomorrow as competencies are achieved by the students at the level of mastery under your guidance.
• The assessments of competencies are directly linked with the objectives of the learning experience and are expected to be continuous and competence-based.
• The assessment results can be used for further improvement of the students.
• Remedial coaching is helpful for the low achievers and enrichment program for the high achievers. Since it aims at mastery of skills by each individual it caters to the learning needs of all categories of students.
• Suitable activities like storytelling, role-playing, dialogue, practice riddle, wordplay, magic, quiz, and puzzle help the students to achieve the competencies in learner-friendly ways.
• The teaching-learning process is joyful and interesting in this approach.

The correct answer is Spleen.

Key Points

• Spleen
  • ​The spleen is the largest organ of the lymphatic system.
  • It keeps all the body fluids balanced.
  • It is made up of red pulp tissue that filters the old and damaged red blood cells, whereas, the white pulp tissue consists of the B and T cells that help to fight infections.
  • The spleen is a bean-shaped organ that stores erythrocytes, lymphocytes, and phagocytes.
  • The spleen recycles the old and damaged red blood cells and the white blood cells are stored.
  • It also helps to fight against bacteria that cause diseases such as meningitis and pneumonia.

Additional Information

• Tonsil
  • Tonsils are the two lymph nodes located on each side of the back of your throat.
  • They function as a defence mechanism and help prevent your body from getting an infection.
  • When it becomes infected, the condition is called tonsilitis.
• Thymus
  • The thymus gland is a very unique organ that is at its largest in children and shrinks away as the body grows older.
  • It is about 2.5 to 5 cm wide, 4 to 6 cm long, and 1cm thick at birth.
• Lymph node
  • A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system, and the adaptive immune system.
  • A large number of lymph nodes are linked throughout the body by the lymphatic vessels.

Explanation: -

First, we need to find the limiting reagent

As per the balanced equation

1:1/2 : 1:2

This means for 1/2 mole of O₂, we need = 1 mole of CH₄

Therefore, for 2 moles of O₂ as given in the question, we need 4 moles of CH₄

But since the question mentions that we are given only 2 moles of CH₄

Thus CH₄ is our limiting reagent.

So, to find the quantity of CO,

Since 1 mole of CH₄ gives 1 mole of CO

Therefore, 2 moles of CH₄ will give 2 moles of CO.

Hence, 2.0 is the correct answer.

Teaching method: Different teaching methods are used by teachers as per the requirements of students. For choosing the one, the teacher may classify students based on their abilities (ability grouping) or he can choose it based on the compatibility of the topic. The following are some of the teaching methods explained:

• An experiment usually helps to establish a cause-effect relationship. It includes enquiry, observation, inferring and testing of a hypothesis. It is not difficult to devise experiments that can generally be fitted within the time allocated to teach a particular topic. To verify theoretical experiments, this teaching method is adopted.
• Discussion takes place whenever there is a difference of opinion concerning the situation. It involves an interchange of questions and ideas among the students/peers. The purpose of the discussion is to encourage an exchange of ideas and viewpoints. Discussion methods may be superior to lectures or reading for the retention of information. This method has been found to be superior in building attitudes that are important in shaping behaviour patterns.
• Concept map provides a concrete record of the connections perceived by the students, and thus it indicates how the student’s knowledge is organised and interconnected.
• Demonstration Method: The word demonstration means to give demos or to perform a particular activity or concept. In demonstration method, the teaching-learning process is carried in a systematic way. Demonstration often occurs when students have a hard time connecting theories to actual practice or when students are unable to understand applications of theories. 

Hence, we conclude that to verify theoretical experiments, this teaching method is adopted.

Key Points

• Water is the only substance on Earth that naturally occurs in three physical states: solid, liquid, and gas.
• Water is an inorganic, transparent, tasteless, odourless, and nearly colourless chemical substance.
• It is the main constituent of Earth's hydrosphere and the fluids of all known living organisms. 
• Water is called the universal solvent because it is capable of dissolving more substances than any other liquid. 
• Depending on the temperature and atmospheric pressure, water can change from one state to another, a process called physical phase change. 
  • The physical state of water at 25°C is liquid. 
  • The physical state of water can be both liquid and solid at 0°C. It is so because 0°C is the melting point of ice as well as the freezing point of water. 
  • The physical state of water can be both liquid or gas at 100⁰C. It is so because 100⁰C is the boiling point of water as well as the condensation temperature of steam.

Concept:

Electropositive elements:

• Electropositive elements have a low attraction towards electrons in a bond.
• Most electropositive elements like Na, K, Mg, have one or two electrons in excess of their octet.
• So losing this one or two electrons from the outermost shell will give them a fulfilled octet.
• Electropositive elements have generally low electron affinity.
• The energy required to take out an electron from its outer shell is also low.

Electronegative elements: 

• They have a high tendency of attraction towards electrons in a bond.
• These elements like F, Cl, S have one or two electrons short of achieving their octet in the outermost shell.
• Thus, they gain one or two electrons to fulfill their octet.
• Their electron affinity is high and they also have high ionization values.

Explanation:

• Element X is strongly electropositive.
• Thus, element X will give out or lose electrons.
• Upon losing one electron, it will achieve positive charge.
• As X is univalent it will lose only one electron and will become X⁺ during bond formation.
• Element Y is strongly electronegative.
• Element Y will thus gain electrons.
• As element Y is univalent, it will accept one electron during bond formation.
• Thus element Y becomes Y^-.
• An example is shown below:

​Thus, the compound formed with these two elements is X⁺Y^-. The nature of the bond formed here is an ionic bond.

Additional Information

• Electronegativity increases while moving across a period and decreases down a group.
• Electropositivity follows just the opposite trend.

​ 

NCF-2005 refers to the National Curriculum Framework published in 2005, by the NCERT. It is the official document which states that the curriculum must be student-centric and beyond the textbooks.

Key Points

Recommendation of NCF regarding Science curriculum at the upper primary stage:

• The scientific concepts to be taught at this stage should be chosen to make sense of everyday experiences as to make the students familiar with the use and application of scientific knowledge in their real life.
• It should focus on developing the cognitive (related to the mental processes), affective (related to the development of emotions of students), and psychomotor domains (related to the development of motor skills).
• It also recommended that the science curriculum should be student-centered i.e., all the teaching-learning activities conducted in science teaching should be in accordance with the needs, desires, and interests of the students.
• The curriculum of science should be inquiry-based to make the students independent discoverers of knowledge that will help them to apply the scientific knowledge into their real life.
• Science education should create opportunities for students to perform research and experiments on their own to explore, discuss, and debate environmental issues, problems of health, etc. so that they can get hands-on experiences that will enhance their conceptual learning of science.
• For example, they can conduct experiments to know the presence of chlorophyll in the leaves of plants and trees. 
• Science should be a core compulsory subject up to Class X as the learned concepts of science will help the students to solve their problems in the real world.

Hint

• Teacher-centered curriculum refers to the active involvement of the teacher in the teaching-learning process while the learners passively listen to the teacher. 

So, it is concluded that NCF recommends a teacher-centered science curriculum, is not a key recommendation as per NCF on the science curriculum

Option 2 is the correct answer: Decomposition reactions are always endothermic in nature.

• In a decomposition reaction, a chemical compound is broken into its constituent components.
• The process takes place through the breaking of bonds between the constituent atoms of the compound.
• The reaction in which heat or light energy is absorbed during the process, are called endothermic reactions.
• In decomposition reactions, the energy is required to break the chemical bonds. therefore they are aways endothermic in nature.
• Combustion reaction - Combustion means reaction with oxygen, hence combustion reactions are generally oxidation reactions (Exothermic).
• Displacement reaction - One constituent component is replaced by some other component (Spontaneous and exothermic).
• Combination reaction - Two or more elements or compounds combine. New bonds are formed and energy is released (Exothermic).

The correct answer is parasitic worms.

Key Points

• Elephantiasis, or lymphatic filariasis, is a painful and disfiguring condition. Infection with parasitic nematodes (roundworms) of the family Filariodidea is transmitted through mosquito bites.
• Mosquito-transmitted larvae land on the skin and can then enter the body. The larvae subsequently travel to lymphatic arteries, where they mature into adult worms, thus perpetuating the transmission cycle.
• The main symptom of elephantiasis is gross enlargement and swelling of an area of the body because of the accumulation of fluid. The arms and legs are the areas most often affected. An entire arm or leg may swell to several times its normal size resembling the thick, round appearance of an elephant's leg.
• Parasitic worms, commonly known as helminths, are huge macroparasites with adults visible to the human eye.
• Many of them are soil-transmitted intestinal worms that infect the gastrointestinal tract.

Important Points

• Bacteria are single-celled organisms with a small size. Bacteria can be found practically everywhere on the globe and are essential to its ecosystems.
• Protozoa are microscopic unicellular eukaryotes with a complex internal structure and a wide range of metabolic functions.
• A virus is a type of infectious microorganism that consists of a nucleic acid segment (DNA or RNA) encased in a protein coat.

The correct answer is 5 June.

Explanation:

• World Environment day is celebrated on 5 June every year and is the United nation's principal vehicle for encouraging awareness and action for the protection of the environment.
• In 1972 the United Nations General Assembly(UNGA) celebrated World Environment day on the first day of the Stockholm conference on the Human Environment.
• Since 1974 it has been regularly organized by the different host countries and with different themes.
• It is motto is engaging governments, businesses celebrities, and citizens to focus their efforts on a pressing environmental issue.
• The theme of first world environment day was ''only one earth"
• The theme of world Environment day 2020 was Time for nature and the host country was Colombia.
• The theme of world Environment day 2021 was ecosystem restoration and the host country was Pakistan calibration with the United Nations Environment Programme.
• the theme of this year's World Environment Day, “Only One Earth", focusing on “Living Sustainably in Harmony with Nature” and the host country is Sweden​

Additional Information

• 5 May celebrate is International midwife day
• The day focuses on the role of midwives and midwifery.
• Midwifery is skilled, knowledgable, and compassionate care for childbearing women newborn infants, and families throughout pre-pregnancy, birth postpartum, and the early weeks of life.
• 15 September is the anniversary of M.Visvesvaraya, and it's celebrated as Engineer's day.​​​

The correct answer is Parents are pure breeding.

• Mendel's laws apply only when parents are pure breeding.

Key Points

• Gregor Mendel, through his experiments on pea plants, discovered the fundamental laws of inheritance.
• He deduced three laws from his experiments and these laws are applicable when parents are pure breeding.
• The three laws of inheritance proposed by Mendel include:
  • Law of Dominance
  • Law of Segregation
  • Law of Independent Assortment

Concept:

• Exocrine glands: The glands which secrete substances on the epithelial surface through the ducts are called exocrine glands. Eg. sweat, salivary, mammary, ceruminous, lacrimal, sebaceous, prostate, and mucous glands.
• Endocrine glands: The glands which secrete hormones and other substances directly into the bloodstream are called endocrine glands. Eg. Pituitary, Pineal, Thyroid, Thymus, Gonads, etc.

​Explanation:

Diabetes insipidus is due to the deficiency of the hormone ''Vasopressin''

• It is also called the Antidiuretic hormone secreted by the posterior pituitary gland.
• It mainly acts on the kidney and stimulates the reabsorption of water by the distal convoluted tubules and thereby reduces the loss of water through urine (Diuresis) so-called antidiuretic hormone
• The deficiency of ''Vasopressin'' results in a disease called 'Diabetes insipidus'.
• Due to a lack of vasopressin, the body cannot retain the required amount of water and it is lost in the urine, so the person feels thirsty all the time.

Additional Information 

• Bleaching powder (CaOCl2) is manufactured through a reaction between slaked lime Ca(OH)2 and chlorine (Cl2).
• When chlorine gas is passed through slaked lime, it reacts with slaked lime and forms bleaching powder.

                      Ca(OH)2 + Cl2 ---->  CaOCl2 + H2O

• Bleaching powder (Calcium hypochlorite) is a pale yellowish powder used as a bleaching agent in the clothing industry.
• It is also used in the laundry. Being a very strong oxidizing agent, it is also used as an oxidizer.
• It is used for disinfecting the water and kill harmful germs present in water.

The correct answer is Cs

Key Points

• In the periodic table, the alkali metals are considered to be the most electropositive elements.
• Electropositive nature increases down the group in the periodic table.
• The elements that can form positive ions by donating electrons are called electropositive elements.
• Metals are electropositive as they donate their valence electron, and non-metals are electronegative as they accept the electron.

Additional Information

• Francium is a more electropositive element than caesium, but it is not stable.
• Fluorine is the least electropositive element.
• Electropositive nature decreases as we move across the row from left to right in the periodic table.
• Electropositive nature increases as we move from top to bottom in the periodic table.

The correct answer is Sericulture.

Key Points

• The rearing of silkworms to produce raw silk is called sericulture or silkworm rearing.
  • Sericulture refers to the rearing of silk-producing organisms to obtain silk in large quantities.
  • It has now taken the form of industry. It is a cottage industry based on agriculture.

Additional Information

• Arboriculture -
  • Arboriculture is the cultivation, management, and study of individual trees, shrubs, vines, and other perennial woody plants.
• Aquaculture -
  • Aquaculture includes the cultivation of freshwater and saltwater under controlled conditions.​
• Apiculture -
  • Bees are reared to get honey, pollen, etc. It is an agricultural industry.​

The correct answer is They transfer energy to the next trophic level in the food chain.

Important Points

• Decomposers are organisms that break down dead or decaying organisms.
• They carry out the natural process of decomposition.
• Types of decomposers are bacteria and fungi.
• Decomposers eventually convert all the organic matter into carbon dioxide and nutrients like nitrogen, phosphorous, magnesium, etc.
• Organisms that feed on dead material in this way are called saprophytes or reducers.

Explanation:

• Trophic system refers to the system in which energy flows from one trophic level to another.
• Trophic level is the specific place in the food chain that is occupied by an organism based on their source of food.
• In a specific food chain, organisms occupy different trophic levels according to the sequence of who-eats-whom.
• The energy in an ecosystem flows from the Producer → Herbivore/Primary Consumer → Carnivore/Secondary consumer.
• Decomposers may act on organisms of all trophic levels.
• As they breakdown the organic matter into its nutrient forms, they do not transfer the energy to any other trophic level. 

Explanation:

Mass

• Mass is the physical value.
• Mass and volume are the two properties used to measure objects. 
• Mass is a persistent or regular property of a body or a material.

Weight

• weight is the force with which a body is attracted toward the Centre of any planet due to its gravity. 
• Weight is a force that pulls on a mass and is measured in Newton.
• It is denoted dimensionally as MLT^-2 
• Weight is dependent on mass as W = mg

Volume

• The volume of matter is how much space the matter occupies.
• Volume is the geometric value.
• It has nothing to do with how much matter there is, but merely how much space that matter takes up.
• The volume of a substance changes as it is dependent on the state of the substance.

Density (ρ)

• Density is the relation between the mass and volume of matter.
• The equation for density is Mass per unit Volume,
• 

Concept:

Light:

• Light is a form of energy, which produces the sensation of vision in our eyes. 
• The objects around us reflect light. The reflected light reaches our eyes and make that thing visible to us. 
• Luminous objects like Sun, stars, electric bulbs etc have their own light and they are considered a source of light. 
• Non Luminous objects are those objects which do not have their own light but reflect the light coming from some source.
• Light travels in a straight line in a given medium. 

Transparent, translucent, and opaque object

• Transparent object: The object that allows light to pass through them or the objects across we can see are transparent objects. Examples. Glass, water.
• Translucent object: The object that partially allows light to pass through them are translucent objects. Example filter paper.
• Opaque object: The object across which light cannot pass are called opaque object, for example, cardboard, books, etc. 

Shadow Formation

• A shadow is a black spot that is formed when an opaque object comes into the path of light. 
• This happens because light travels in a straight line and if there is any obstacle in between the light could not pass through it.
• It is formed on the screen which could be a wall or anything like that. 
• The size of the shadow depends upon the distance between opaque objects and sources of light. 

Explanation:

For the shadow formation, source of light, screen and opaque object all are required. 

So, these properties of light can be used to explain the phenomenon of shadow formation:

A. Light travels in a straight line.

D. Light does not pass through opaque objects.