Factors Affecting Vegetation

The direct answer is A: natural vegetation consists of plants that grow without direct human help. It develops under the natural combination of local climate, soil, water, relief, and temperature. Step by step: seeds germinate and plants establish themselves naturally; people do not regularly sow, irrigate, weed, or manage them as a crop; the resulting plant community is called natural vegetation. Option A is correct. Option B describes cultivated crops, which are deliberately sown and managed in fields. Option C is wrong because plants in pots are usually deliberately grown and cared for, so they are not the definition of natural vegetation. Option D is wrong because being sold in a market says nothing about how a plant grew. Natural vegetation can later be collected or sold, but that does not change the definition. Memory cue: natural vegetation grows by nature, not by planned cultivation.

Climate affects vegetation through temperature rainfall and light. Exam tip: treat climate as a main factor.

Rainfall increases soil moisture and gives water to plants. Exam tip: remember the link between rainfall and vegetation density.

In low rainfall areas plants may be thorny with small leaves to save water. Exam tip: connect dry areas with thorny vegetation.

Evergreen forests develop in high rainfall and warm humid conditions. Exam tip: connect evergreen forests with year round greenery.

Very high or very low temperature can limit plant growth. Exam tip: remember temperature as a climatic factor.

Plants make food through photosynthesis. Exam tip: remember the link between sunlight and food making.

Photoperiod can affect plant growth and flowering. Exam tip: remember it as duration of sunlight.

The direct answer is D: soil gives plants nutrients, water and support. Soil is not merely the surface on which a plant stands. Its spaces can store water and air, and dissolved minerals can be absorbed by roots. Step by step: roots grow through soil; soil holds the roots and keeps the plant upright; water in the soil dissolves minerals; roots absorb water and nutrients; the plant uses them to make food and build tissues. Soil also influences drainage and aeration. D is correct because it includes the three basic services named in the question. A is wrong because colour does not feed or support a plant. B is wrong because soil does not provide sound. C is wrong because some soil or plants may create shade, but shade alone is not the main role of soil. Memory cue: soil is the plant's anchor, water store and nutrient store.

Fertile soil provides necessary nutrients to plants. Exam tip: remember the relation between nutrients and growth.

Sandy soil may have low water holding capacity. Exam tip: remember the relation between soil texture and moisture.

Clayey soil can hold water for a longer time. Exam tip: study soil type and moisture together.

Mangroves grow in saline and marshy coastal areas. Exam tip: connect mangroves with coast and salinity.

Altitude and slope affect temperature soil and runoff. Exam tip: understand relief through altitude and slope.

Temperature decreases with altitude and vegetation types change. Exam tip: remember the relation between altitude and temperature.

The direct answer is A: running water can wash away soil. On sloping land, gravity pulls water downhill, so rainwater often moves faster than it would on level ground. Step by step: rain falls on the slope; water begins to flow downhill; faster flow has greater ability to detach soil particles; the particles are transported away, especially when vegetation cover is poor. This process is water erosion. A is correct. B is irrelevant because language has no role in the physical removal of soil. C is wrong because slopes can receive rainfall; the statement says rainfall never occurs, which is false. D is absurd because soil does not become gold through erosion. The amount of erosion also depends on rainfall intensity, soil type, slope steepness and plant cover, so the question correctly says it can be higher, not that it is always higher. Memory cue: steep slope plus fast runoff means greater erosion risk.

Waterlogging can damage roots. Exam tip: remember the relation between drainage and root health.

Amount of rainfall affects the type and density of vegetation. Exam tip: connect high rainfall with dense forests.

Fertile plains are more changed for human use. Exam tip: connect land use with vegetation change.

Human farming is limited on difficult slopes so vegetation can remain. Exam tip: remember the effect of relief.

Photosynthesis is the process by which green plants prepare food. Light energy is needed to drive this process, and sunlight is the usual natural source of that energy. Plants also use water and carbon dioxide, while chlorophyll helps capture light. The food made by photosynthesis supports plant growth and supplies energy to many organisms through food chains.

Option A is correct because sunlight provides the energy required for photosynthesis. Plastic, cement, and smoke are not ingredients that enable plants to make food. Although sunlight alone is not the complete requirement, it is the only relevant need listed among the choices. The question therefore correctly links sunlight with plant food production.

In low rainfall areas plants develop thorny forms to save water. Exam tip: connect dry climate with thorny vegetation.

Heavy rainfall supports fast plant growth. Exam tip: connect heavy rainfall with dense forests.

Alluvial soil is fertile so farming is common there. Exam tip: connect alluvial soil with fertile plains.

Sandy soil holds less moisture and low rainfall forms sparse vegetation. Exam tip: connect sandy soil with desert vegetation.