Figure (a) appears more accurate because it is showing positive geotropic movement in roots and negative geotropic movement in stem.

Paper, rexin bag, blade, pen, plastic box, scale, eraser, compass and dividers (metallic), steel lunch box and steel spoon. Paper, blade, plastic box, eraser, compass, steel lunch box and steel spoon can be recycled.

Concave mirror.
When a solar furnace is placed at the focus of a large concave mirror, it focusses a parallel beam of light on the furnace, as a parallel beam of light on the furnace, as a result a temperature is achieved after some time.

In the formula \(m=\frac { { h }_{ 2 } }{ { h }_{ 1 } } =\frac { -v }{ u } \), the sign of m is determined by the signs of h₁ and h₂ . When m is positive, the image is virtual and erect. When m is negative, the image is real and inverted.

In a crop field, plants do not grow naturally rather most of the plants are grown by humans. An ecosystem is nevertheless present in a crop field, but it is an artificial ecosystem as a major component of the ecosystem comes into origin because of human intervention.

(a) No
(b) Though animals have a vast diversity in structures they, do not have a common ancestry. This is because common ancestry may limit the extent of diversity. As many of these diverse animals inhabit the same habitat, their evolution by geographical isolation and speciation is also not likely.

Eka-Silicon is germanium (Ge). It lies in group IV of the Mendeleev's periodic table and thus has a valency of 4. Therefore, the formula of its chloride is GeCl. Eka ₄. Eka-aluminium on the other hand is gallium (Ga). It lies in group III of the Mendleev's periodic table and thus has a valency 3. Therefore, the formula of its chloride is GaCl₃.

When the colony of yeast is in water, it does not get nutrition, because water does not have nutrients. Sugar, on the other hand, provides nutrition. Once the yeast gets nutrition, it grows and begins producing buds. That is why, colonies of yeast fail to multiply in water, but multiply in sugar solution.

a) The electronic configuration of chlorine with atomic number 17 is
K L M
2 8 7
b) Electron dot structure of chlorine molecule Cl2 is

Electric fan, mixer grinder, tape recorder, CD player, hard disk drive, washing machine, cooler, toy car, vacuum cleaner, etc.

The plant which is kept in continuous light would live longer. The plant which is kept in the dark is unable to carry out photosynthesis and hence the container within a short span of time. Lack of oxygen in the container would kill the plant. On the other hand, the plant being kept in light would be able to carry out photosynthesis and thus would be able to convert the carbon dioxide into oxygen. Hence this plant would live for a longer duration.

(a) No, because oxygen is added to aluminium therefore, it is getting oxidised.
(b) No, since manganese has lost oxygen therefore, it is getting reduced.

a) using smokeless devices.
b) Afforestation.

The student adds turmeric to the two beakers.  The basic solution turns the turmeric into reddish-brown in basic solution.  On the other hand, she added few drops of phenolphthalein solution to the beakers.  If a colourless substance is produced, the substance is acidic and if a pink colour is produced, the solution said to be basic.