Question
Describe the different layers in soil profile.
✓
Answer
Different layers of the soil are referred to as horizons:
- The uppermost layer, the top soil, also known as A-horizon is generally dark in colour and fertile as it is rich in humus and minerals. This layer is generally soft, porous and can retain more water. This provides shelter for many living organisms such as worms, rodents, moles and beetles. The roots of small plants are embedded entirely in the topsoil.
- The next layer, middle layer called B-horizon has a lesser amount of humus but more of minerals. This layer is generally harder and more compact.
- The third layer is the C-horizon which is made up of small lumps of rocks with cracks and crevices.
- Below this layer is the bedrock, which is hard and difficult to dig with a spade. Water can be held in the tiny gaps.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Match the following:
→|
$(i)$
|
Land breeze blows during
|
$(a)$
|
summer
|
|
$(ii)$
|
Sea breeze blows during
|
$(b)$
|
winter
|
|
$(iii)$
|
Dark coloured clothes are preferred during
|
$(c)$
|
day
|
|
$(iv)$
|
Light coloured clothes are preferred during
|
$(d)$
|
night
|
How do elephant living in the tropical rainforest adapt itself?
Observation : Table : Appearance, hardness, and effect of hammering on different objects or materials
| Object/Material | Appearance (lustrous/non-lustrous) | Hard/Soft | Effect of hammering (fattens/ breaks into pieces) |
| Piece of copper | |||
| Piece of aluminium | |||
| Iron nail | |||
| Piece of coal | |||
| Lump of sulphur (pea-sized) | |||
| Block of wood |
Explain the mechanism of breathing with a model.
Explain how sonority and conductivity help in daily life.
Ravi was sitting in a garden with his family. His younger sister comes running with different types of flowers and starts to name their parts. She stops as she forgets some names and Ravi noticing this comes to help her. His sister askes many Questions related to flowers and Ravi answers her with all information he has.
- What is a flower and mention its function during reproduction?
- Flowers help in pollination and fertilisation. Yes/ No? Give reason.
- Do all flowers have both male and female parts on them specify?
- What values are observed in Ravi and his sister?
If you leave a piece of iron in the open for a few days, it acquires a film of brownish substance, called rust.
(i) Do you think rust is different from iron?
(ii) Can you change rust back into iron by some simple method?
(iii) Do you think formation of rust on iron is a chemical change?
(iv) Give two other examples of a similar type of change.
(i) Do you think rust is different from iron?
(ii) Can you change rust back into iron by some simple method?
(iii) Do you think formation of rust on iron is a chemical change?
(iv) Give two other examples of a similar type of change.
Label the following figure of the digestive system.
A part of human digestive system
Explain the function and components of blood.
In towns and cities, generally, the bore wells have to be dug very deep to get water as compared to bore wells dug in villages. Give suitable reasons.