Nutrition in Plants Test - 9

Guard cells are found in stomata. Guard cells regulate the opening and closing of the stomatal pore. The guard cells and the stomatal pore together constitute the stomata. Stomata are found in leaves. It is through the stomatal pore, the exchange of gases and process of transpiration takes place.

During photosynthesis, water (with dissolved minerals) from the soil and CO$$_2$$ from the atmosphere are taken up as raw materials by the plant. The plant in the presence of sunlight, chlorophyll, and suitable temperature, utilizes the raw materials to make food. This food is primarily glucose. Also, during photosynthesis, oxygen is given out as a by-product. So, glucose and oxygen are not used during photosynthesis; instead, they are produced during photosynthesis. 

• The nucleus, cell membrane, and cytoplasm are considered the basic components of any eukaryotic cell since these are present in all eukaryotic cells. 
• Vacuoles are found in both animal and plant cells but size varies.
• Cell walls and chloroplast are absent in animal cells.

Hence, the correct answer is option D.

• Some plants cannot produce their own food and must obtain their nutrition from outside sources—these plants are heterotrophic. For example - dodder is a parasitic plant that derives nutrition from its host.
  
• Autophytes are plants that can manufacture their own food. 
• Halophytes are plants that grow in extremely saline conditions. 
• Holophytes are the organism that prepares their food by photosynthesis.

So, the correct answer is option B.

Stomata are small elliptical openings on leaves that contain chloroplasts. They are girdled by two-kidney shaped cells known as guard cells on either side of the stoma. The guard cells possess a thick inner wall and a thin outer covering which control the closing and opening of the pores of stomata.

 So, the correct answer is option B.

• Rhizobium is soil bacteria, that fix nitrogen after becoming established inside root nodules of legumes (Fabaceae). 
• To fix nitrogen, Rhizobium requires a plant host; they cannot independently fix nitrogen. In general, they are Gram-negative, motile, non-sporulating rods. 
• In presence of nitrogen, they can fix nitrogen. So, supplying nitrogen to them can be helpful for nitrogen fixation.

• Green plants are autotrophic organisms because they can synthesize their own food by photosynthesis. 
• During photosynthesis energy from sunlight is converted into chemical energy in the form of organic compounds and oxygen is released as a by-product.
•  Animals, fungi and several bacteria are heterotrophic organisms and depend on organic compounds synthesized by autotrophs for their nutrition.
• So, the correct answer is 'Autotrophs'

The organisms which synthesize their own food from co2, chlorophyll and sunlight through photosynthesis are known as autotrophs. And their mode of nutrition is known as autotrophic nutrition. So the correct answer is (c)

• Organisms that cannot synthesize their own food are called heterotrophs. Heterotrophs depend directly or indirectly on autotrophs for their food.
• Autotrophs are the organism that can produce their own food using light, water, carbon dioxide, or other chemicals.
• Algae are autotrophs.

So, the correct answer is option B.