Question

Few plants cannot synthesise food on their own and depend upon other plants and small animals. They are called heterotrophic plants. These heterotrophs are classified in
a. Thallophytes and bryophytes.
b. Saprophytes and parasites
c. Xerophytes and hydrophytes
d. Saprophytes and pteridophytes

Answer 1

Plants are autotrophs which means they can prepare their own food. Few plants like pitcher plants cannot prepare their food and eat small insects. These plants are heterotrophs which depend on others for food. The heterotrophs adopt different ways to obtain food.

Complete answer:
• Thallophytes- These are the plants having a simple body called the thallus. It comprises algae, fungi, lichens.

• Bryophytes- These are the group of plants which are non- vascular. They are autotrophs. Example liverwort, hornwort.

• Saprophytes- These are the heterotrophic organisms which derive their nutrition from the dead organic matter. They involve extracellular digestion. Example- fungi, soil bacteria, mushroom moulds.

• Parasites- It is also a heterotrophic mode of nutrition in which the organism obtains its nutrients from a host plant and in return destroys the host. Example- Viscum, cucusta.

• Xerophytes- These are the plants which thrive in arid conditions. They are autotrophs. Example- Cactus.

• Hydrophytes- These are the autotrophs which live in aquatic environments. Example- Vallisneria.

• Pteridophytes- These are the vascular plants which disperse spores. They do not bear seeds or flowers. They are autotrophs. Example- ferns.

From the above discussion we can conclude that the heterotrophs are classified as saprophytes and parasites.
Hence the correct answer is option (b).

Note: The other type of heterotrophic plants thrives by symbiosis or mutualism. Both the plants in association help each other. One provides nutrition or food and the other either provides support or replenishes with other vital nutrients. Example- Rhizobium and leguminous plants.