(i) It burns without smoke and therefore causes less pollution.
(ii) An excellent way to get rid of organic wastes like bio-waste and sewage material.
(iii) Left over slurry is good manure rich in nitrogen and phosphorus.
(iv) It is safe and convenient to use.
(v) It can reduce the amount of green house gases emitted.

Parental generation:
i) Pure breeding tall plant and a pure breeding dwarf plant (tt).
F₁ generation:
i)  Plants raised from the seeds of pure breeding parental cross in F₁ generation were tall and monohybrids.
F₂ generation:
i) Selfing of the F₁ monohybrids resulted in tall and dwarf plants respectively in the ratio of 3:1.
ii) The actual number of tall and dwarf plants obtained by Mendel was 787 tall and 277 dwarf.
iii) External expression of a particular trait is known as phenotype. So the phenotypic ratio is 3:1.
In the F₂ generation 3 different types were obtained:
i) Tall Homozygous - TT (Pure) - 1.
ii) Tall Heterozygous - Tt - 2.
iii) Dwarf Homozygous - tt -1.
So the genotypic ratio 1:2:1.
(A genotype is the genetic expression of an organism).

1. Click events in script option

3. Click Looks in script option. Drag “say” to script area.

4. Type “Hello “ word in say tab.

5.Click sounds in script option. Drag play sound to script area. Choose the hello sound from the audio file.

6. From File menu choose the Save option.
7. Click the green flag at the top right corner of the stage window to run the program

The hormones secreted by the posterior pituitary are:
Vasopressin or Antidiuretic hormone (ADH)
In kidney tubules it increases reabsorption of water.
Oxytocin
It helps in the contraction of the smooth muscles of uterus

(i) Sometimes cells, tissues and organs in the body may be permanently damaged or lost due to genetic to disease or injury.
(ii) In such situations stem cells are used for the treatment of diseases which is called stem-cell therapy.

(i) The formation of sperm is in a particular temperature which is less than our body temperature. So it is located in the outside of the body.
(ii) The name of the pouch is scrotum.

Sino-atrial node is called the 'pacemaker' of heart because it is capable of initiating impulse which can stimulate the heart muscles to contract thereby pushing the blood into the ventricles.

(i) Ethnobotany is the study of a region's plants and their practical uses through the traditional knowledge of the local culture of people.
Importance of Ethnobotany :
(i) It provides traditional uses of plant.
(ii) It gives information about certain unknown and known useful plants.
(iii) The ethnomedicinal data will serve as a useful source of information for the chemists, pharmacologists and practitioners of herbal medicine.
(iv) Tribal communities utilize ethnomedicinal plant and prepare medicine to cure many  diseases.

(i) For diabetic patients, the food to be avoided are:
a. Refined sugars (sucrose and glucose).
b. Saturated fat intake should be reduced.
These food release sugars rapidly in the blood stream.
(ii) The food to be included in diabetic patients are:
a. Flax seeds containing insoluble fiber, Guavas, Tomatoes and Spinach.
b. Diet comprising whole grains, millets (jowar, bajra, ragi), green leafy vegetables, wheat and unpolished rice should be included in diet regularly. These foods help reduce blood sugar levels.

Respiratory quotient is the ratio of volume of carbon dioxide liberated and the volume of oxygen consumed during respiration. It is expressed as
RQ = \(\frac{Volume \ of \ { CO }_{ 2 } \ liberated}{Volume \ of \ { O }_{ 2 } \ consumed}\)

mass of solute = 45 g
mass of solvent = 180 g
Mass of Percentage = ?
Mass of percentage = \(\frac{Mass \ of \ the \ solute}{Mass \ of \ the \ solution \ + \ Mass \ of \ the \ solvent}\) x 100
= \(\frac{45}{45 + 180} \times 100=\frac{4500}{225}\)
Mass percentage = 20%

(i) Our body works within the pH range of 7.0 to 7.8.
(ii) Different body fluids have different pH values.
(iii) Any increase or decrease in this value leads to diseases.
(iv) The ideal pH for blood is 7.4.
pH in our digestive system:
(i) HCl present in our stomach helps in digestion.
(ii) During indigestion our stomach produces more acid and this causes pain and irritation.
(iii) pH of the stomach fluid is approximately 2.0.
pH changes as the cause of tooth decay:
(i) pH of the saliva normally ranges between 6.5 to 7.5.
(ii) White enamel coating (calcium phosphate) is a hard substance in our body.
(iii) When the pH value falls below 5.5, it weathers.
(iv) The basic toothpaste neutralises the excess acid and prevents tooth decay.
pH of soil:
(i) Citrus fruits require slightly alkaline soil, rice requires acidic soil and sugarcane requires neutral soil.
pH of rain water:
(i) The pH of rain water is approximately 7.
(ii) If the atmospheric air is polluted with oxides of non-metals, they get dissolved in the rain water and make its pH less than 7.
(iii) As its pH value is less than 7, then it is called acid rain.
(iv) When this rain water reaches river water, the survival of aquatic life becomes difficult.

(i) Copper gets covered with a green layer of basic copper carbonate in the presence of CO₂ and moisture.
(ii) \(2 \mathrm{Cu}+\mathrm{O}_{2}+\mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{CuCO}_{3} \cdot \mathrm{Cu}(\mathrm{OH})_{2}\)
(iii) Copper reacts with con. \(\mathrm{H}_{2} \mathrm{SO}_{4}\) to from copper sulphate and SO₂.
(iv)  \(\mathrm{Cu}+2 \mathrm{H}_{2} \mathrm{SO}_{4} \rightarrow \mathrm{CuSO}_{4}+\mathrm{SO}_{2} \uparrow+2 \mathrm{H}_{2} \mathrm{O}\)
(v)  So, A is-Copper (Cu)
\(\mathrm{B}\ is \ -\mathrm{CuCO}_{3} \cdot \mathrm{Cu}(\mathrm{OH})_{2}\) Basic copper carbonate.
\(\mathrm{C}\ is \ -\mathrm{CuSO}_{4}\) (copper sulphate)
\(\mathrm{D}\ is \ -\mathrm{SO}_{2}\) (Sulphur oxide)

(i) Slime glands are present in the body wall. Their secretion keeps the body moist and slippery so that the host can't remove it easily while it sucks  blood.
(ii) The availability of the host to the leeches is not regular. Hence, a large amount of blood is stored in the crop whenever it gets food. Digestion is also very slow.
(iii) It may take more than a year for the complete digestion after a full meal.
(iv) In leech the ingested blood is stored in crop chambers. It may take more than a year for the complete digestion and absorption of a full meal. So there is no need for an elaborate secretion of digestion juices and enzymes.