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(i) Fishes respire with the help of gills. Gills are richly supplied with blood capillaries and can readily absorb oxygen dissolved in water. Since fishes cannot absorb gaseous oxygen they die soon after they are taken out of water. 

(ii) Aquatic organisms like fishes obtain oxygen from water present in dissolved state through their gills. Since the amount of dissolved oxygen is fairly low compared to the amount of oxygen in the air, the rate of breathing in aquatic organisms is much faster than that seen in terrestrial organisms.

Mutual induction is the phenomenon of production of induced emf in one coil due to change of current in the neighbouring coil. The coil in which the current changes is called primary coil and the coil in which emf is induced is called the secondary coil.

They are used to make standard resistors because :

• They have high value of resistivity.
• Temperature coefficient of resistance is less.
• They are least affected by temperature.

Difference between binary fission and multiple fission : 

The distance from centre of nucleus to outermost shell of an atom is atomic radius. 

Atomic radius decreases across a period because electron is added in the same shell. So, attraction between nucleus and valence shell increases due to which outermost shell is pulled in closer to the nucleus.

Baking powder (NaHCO₃), Salt A is commonly used in bakery products. On heating, it forms sodium carbonate (Na₂CO3), B and CO₂ gas, C is evolved. When CO₂ gas is passed through lime water it forms calcium carbonate (CaCO₃), which is slightly soluble in water making it milky. 

A — NaHCO₃;    B — Na₂CO₃;      C — CO₂ gas

If waxy coating is made on the surface of leaf, loss of water in the form of water vapour does not take place. Even the gaseous exchange will not take place. So, photosynthesis will either be reduced or will not take place. The plant will not remain healthy for long because: 

(i) Exchange of gases will not take place. 

(ii) Photosynthesis will either be reduced or will not take place due to lack of CO₂. 

(iii) Transpiration will not take place, so there will be no mechanism of cooling in hot weather.

Drift velocity is defined as the average velocity which the electrons are drifted towards the positive terminal under the effect of applied electric field.

V_d=\(-\frac{eE\tau}{m}\)

Periodicity in properties of elements in the modern periodic table means the repetition in the properties of the elements at regular intervals when arranged according to increasing atomic number. 

Elements in the same group have similar properties as their electronic configurations have the same number of electrons in the outermost shell. 

Tendency to gain electrons increases on moving from left to right in a period as the effective nuclear charge increases and the atomic radius decreases.

Periodicity in properties of elements in the modern periodic table means the repetition in the properties of the elements at regular intervals when arranged according to increasing atomic number.
Elements in the same group have similar properties as their electronic configurations have the same number  of electrons in the outermost shell Tendency to gain electrons increases on moving from left to right in a period as the effective nuclear  charge increases and the atomic radius decreases.

(i) When the elements having similar chemical properties are repeated at a regular interval, this is known as periodicity of elements. In modern periodic table (which is based on atomic number), we see that the elements having similar chemical properties are repeated at a certain interval of atomic number. 

(ii) This is because the elements of same group have same number of valence electrons or they have similar electronic configuration. For example, all alkali metals (like sodium, potassium, etc.) have 1 valence electron. 

(iii) The tendency to gain electrons across a period from left to rightincreases. This is because the effective nuclear charge increases and consequently it becomes easier for the atoms to gain electrons.

Advantage of frequency modulation over amplitude modulation.
(i) Noise can be reduced
(ii) Transmission efficiency is more because the amplitude of an FM wave is constant.

(a) Repetition of properties after a certain interval is called periodicity of properties. If elements are arranged in increasing order of their atomic number in the periodic table, then elements repeat its properties after a definite interval.This repetition of properties is known as periodicity of properties.

(b) They have similar properties because:

(i) They all have same number of valence electrons.

(ii) They all have same valency.

(c) The tendency to gain electrons increases due to increase in the nuclear charge. Due to this, atomic size decreases and a large number of valence electrons are held towards the nucleus and tendency to gain electrons increases.

It is the mode of nutrition in which an organism cannot make its own food and depends on other organisms for food. All the animals including man, most bacteria and some fungi have heterotrophic mode of nutrition and these organisms are called heterotrophs. 

Three types of heterotrophic nutrition are Holozoic, Saprophytic and Parasitic.

By changing current in another coil placed near it.

Emitter: It is of moderate size and heavily doped, supplies the majority carriers.

Base: It is very thin and moderately doped.

Junction where proper interaction between emitter and collector takes place.

The following two observations we would make when quicklime is added to water:

(i) A hissing sound is observed.

(ii) The mixture starts boiling and lime water is obtained.

During pregnancy, placenta produces hormones like human chorionic gonadotropin, human placental lactogen and ovary produces relaxin.

The function of three segments of a transistor are:  

Emitter: Emits the majority charge carriers 

Collector: Collects the majority charge carriers 

Base: Base provides the interaction between the collector and the base

Definition of Dispersion : Splitting of white light into seven constituent colours by a prism.

Cause of dispersion : When white light passes through a glass prism, different constituent colours bend through different angles with respect to the incident ray and hence are separated.

Some harmful effects of agricultural practices on environment are: 

(i) Excessive use of fertilisers changes the chemistry of soil and kills useful microbes. 

(ii) Excessive use of non-biodegradable chemical pesticides leads to biological magnification. 

(iii) Extensive cropping causes loss of soil fertility. 

(iv) Excess use of ground water for agriculture lowers the water table. 

(v) Damage to natural ecosystem/habitat.

When the man sitting on a boat drinks water, the level of the water tend to decrease as a result of decrease in the volume of water in the pond. As the man gulp down the water, his weight will also increase by mass m. Due to increase in the weight of the man, the boat will sink a little and displace the the same volume of water drank by the man. Hence, the level of water in the pond raised is equal to the level fallen when the man drank the water.  

Thus, the level of water will remain unchanged. 

(a) If we dig into the earth and start finding fossils, it can be assumed that the fossils closer to the surface are more recent to those found in the deeper layers. 

(b) By detecting the ratios of different isotopes of the same element in the fossil material.

Fossils are dead remains of animals and plants from remote past. Fossils are formed when dead organisms are not completely decomposed. The organisms may get trapped in resins of tree, lava of volcanoes or hot mud, which when hardens retains the animal’s parts thus forming fossils.

Two methods of determining the age of fossils are:
(a) Relative method: By estimating the age of the layer of earth’s crust where the fossil is found. Fossils near the surface are recent and those in the deeper layers are ancient.
(b) Radio-carbon dating method: By detecting the ratios of different isotopes of carbon in the fossils. Fossils play the following roles:
(i) By determining the age of fossils we come to know the type of earth strata present at that time.
(ii) We can also know the type of animals and plants present on the earth at that time.
(iii) They help in establishing evolutionary relationship by providing connecting links. (Any one)

(i) Characters are controlled by discrete units called factors 
(ii) Factors occur in pairs 
(iii) In a dissimilar pair of factors one member of a pair dominates (dominant) the other (recessive)

Yes, breastfeeding is important for newborn babies. The milk produced during initial stages of lactation called colostrum is a rich source of antibodies. This antibodies protect the baby from external viral and bacterial infection. It also has a balanced nutrients, which is extremely beneficial for newborn babies.

Yes,

provides nutrition (calcium , fats , lactose ) / provides (passive) immunity / provides antibodies / Ig A

Detailed Answer :

Yes, breastfeeding is important for newborn babies. The milk produced during initial stages of lactation called colostrum is a rich source of antibodies. This antibodies protect the baby from external viral and bacterial infection. It also has a balanced nutrients, which is extremely beneficial for newborn babies.

(a) 19.4%
(b) -Trees are axed for timber / firewood / land for industrial requirement
-Slash and burn agriculture
- habitat loss and fragmentation- clearing of forest land into grass land for raising cattle
(c) -Deterioration of our environment in terms of air - water and soil quality.
-causes loss of bio diversity
- disturbance in hydrological cycle / biogeochemical cycle
(d) Reforestation or any other appropriate alternative

a is continuous synthesis. 

b is discontinuous synthesis.

(a) Orderly and sequential changes parallel with changes in physical enviromment 
(b) climax community-changes finally lead to a community that is in equilibrium with environment  Sere-the entire sequence of communities that successively change in a given area

Correction of genetic defect / involves delivery of a normal gene to take over the function of nonfunctional
gene

Griffith observed a change of living R-strain Streptococcus Pneumoniae (non-virulent type) into living S-bacteria, when injected along with heat-killed S-type (virulent) and called transformation. The phenomenon was discovered by Frederick Griffith 1928. The R-strain non-virulent bacteria pick up the trait of virulence from dead bacteria Griffith Proposed that the transforming principle' is a chemical substance released by heat-killed bacteria. It was a permanent genetic change as the new S-type bacteria formed only S-type.

• Predators act as conduits for energy transfer across trophic levels.
• They keep prey population under control.
• They help in maintaining species diversity in a community by reducing intensity of competition among competing prey species.
• An efficient predator may cause extinction of prey species

He concluded that the R-strain bacteria had somehow been transformed by heat- killed S-strain bacteria, this must be due to transfer of genetic material.

Griffith observed a change of living R-strain Streptococcus Pneumoniae (non-virulent type) into living S-bacteria, when injected along with heat-killed S-type (virulent) and called transformation. The phenomenon was discovered by Frederick Griffith 1928. The R-strain non-virulent bacteria pick up the trait of virulence from dead bacteria Griffith Proposed that the transforming principle' is a chemical substance released by heat-killed bacteria. It was a permanent genetic change as the new S-type bacteria formed only S-type.

-ABO blood group in humans is contributed by gene 'I' that has 3 alleles 'IA' 'IB' and 'i.'
- Because human beings are diploid each person has two of the three alleles.
- IA and I B produce two different types of sugar while allele i does not produce sugar on the plasma membrane of RBC
- When IA and I B are present they both express their own type of sugar- this is codominance

The Glomus helps the plant in absorption of essential nutrients / phosphorus from the soil , and the plant in turn provide the fungus with energy yielding carbohydrate

A new organism develops from an unfertilised egg / without fertilization of an egg  e.g Drones /turkey / Rotifers / some lizards (whiptail)

Failure of segregation of chromatids during cell division cycle results in the gain or loss of chromosome/ called aneuploidy  E.g Down' syndrome results in the gain of extra copy of chromosome 21 Turner's syndrome results due to loss of an X-chromosome in human female

(1) Glucose does not give 2,4- DNP test.

(2) Glucose does not give Schiff’s test.

(3) The pentaacetate of glucose does not react with hydroxylamine.

(4) Glucose does not form the hydrogensulphite addition product with NaHSO₃.

(a) Amylopectin.

(b) C- 2

(c) Two peptide linkages.

The correct option is (c) Sodium hydrogen carbonate and tartaric acid.

•    Sodium bicarbonate is NaHCO₃ Tartaric acid is C₄H₆O₆ So, the reaction is: 

•    NaHCO₃ + C₄H₆O₆ + 2H₂O(l) → 5CO₂(g) + NaOH + 5H₂(g)

The correct option is (d) (B), (C) and (D).

•    Sodium sulphate chemically reacts with barium chloride in the form of their aqueous solution to form a white precipitate of barium sulphate. 

•    This is a double displacement reaction in which sulphate ions are displaced by chloride ions and vice-versa.

The correct option is (d) Double displacement reaction.

The reactions in which two compounds react by an exchange of ions to form two new compounds are called double displacement reactions.

(i) Given, a b then ∠1 = ∠5 [Corresponding angles] 

If two parallel lines are cut by a transversal, each pair of corresponding angles are equal in measure. 

(ii) Given, ∠4 = ∠6, then a b [Alternate interior angles] 

When a transversal cuts two lines such that pairs of alternate interior angles are equal, the lines have to be parallel.

(iii) Given, ∠4 + ∠5 = 180°, then a b [supplementry angle]

 When a transversal cuts two lines, such that pairs of interior angles on the same side of transversal are supplementary, the lines have to be parallel.

Fartlek is a Swedish term meaning speed play. Used for development of Endurance. Blend of continuous training and interval training. Duration:45 min, Heartbeat:140-150 beats/min 

Advantages: 

1. Good aerobic and anaerobic fitness 

2. Flexible in nature 

3. More number of athletes can take part 

4. Easily adapted 

5. No equipment required. 

6. Versatile

Few suggestive measures to overcome barriers to effective communication 

(i) Clarify the ideas before communication: The problem to be communicated to subordinates should be clear in all its perspective to the executive himself. The entire problem should be studied in depth, analysed and stated in such a manner that is clearly conveyed to subordinates. 

(ii) Communicate according to the needs of receiver: Manager should adjust his communication according to the education and understanding levels of subordinates. 

(iii) Consult others before communicating: Before actually communicating the message, it is better to involve others in developing a plan for communication. Participation and involvement of subordinates may help to gain ready acceptance and willing cooperation of subordinates. 

(iv) Be aware of languages, tone and content of message: The language used should be understandable to the receiver and should not offend the sentiments of listeners. The message should be stimulating to evoke response from the listeners. 

(v) Convey things of help and value to listeners: While conveying message to others, it is better to know the interests and needs of the people with whom you are communicating. If the message relates directly or indirectly to such interests and needs it certainly evokes response from communicatee. 

(vi) Ensure proper feedback: The communicator may ensure the success of communication by asking questions regarding the message conveyed. The communication process may be improved by the feedback received to make it more responsive. 

(vii) Communicate for present as well as future: Generally, communication is needed to meet the existing commitments to maintain consistency; the communication should aim at future goals of the enterprise also. 

(viii) Follow up communications: There should be regular follow up and review on the instructions given to subordinates. Such follow up measures help in removing hurdles if any in implementing the instructions. 

(ix)Be a good listener: Manager should be a good listener. Patient and attentive listening solves half of the problems. Managers should also give indications of their interest in listening to their subordinates.