what are heterotrophic nutrition? what are the different types of heterotrophic nutrition found in plants ? define and explain each given exaplain?
ANS: Heterotrophic Nutrition:
It is a mode of nutrition in which the organisms obtain readymade organic food from outside sources. The organisms that depend upon outside sources for obtaining organic nutrients are called heterotrophs. Heterotrophic nutrition is of three types parasitic plants , insectivorous plants , symbiotic plants
Parasitic Plants:
A parasitic plant is one that partially or completely depends on another plant (called host) for nutrition.
Usually, parasitic plants develop special roots, which penetrate into the tissues of the host plant. The prepared food is generally absorbed from the root or the stem of the host plant. Some examples are Cuscuta (dodder) and mistletoe.
Insectivorous Plants:
Insectivorous plants are plants that derive some or most of their nutrients by trapping and consuming animals, mainly insects. These plants mostly grow in places where either the soil is deficient in certain nutrients (e.g., nitrogen) or too little light is available to carry out photosynthesis.
Hence, these plants need to obtain the required nutrients from other sources. Some examples are the pitcher plant, Drosera (sundew), bladderwort, and the Venus flytrap.
The leaf of the pitcher plant is modified to form a tubular pitcher-like structure. The inside of the pitcher is lined with downward pointing hair that do not allow any trapped insect to climb up and escape. The fluid at the bottom of the pitcher contains digestive juices that digest the insect.
Symbiotic Plants:
Certain plants live in association with other organisms, share food and other resources. Both the types mutually gain from each other. Such plants are called symbiotic plants and the relationship is called symbiotic. A good example is lichens.
Answers
Answer:
Heterotrophic nutrition is a mode of nutrition in which organisms depend upon other organisms for food to survive.
Types of Heterotrophic Nutrition
- Holozoic Nutrition.
- Saprophytic Nutrition.
- Parasitic Nutrition.
Holozoic Nutrition
Holozoic nutrition involves the ingestion and internal processing of solid and liquid food in an organism. This involves the steps of ingestion, digestion, absorption, assimilation and excretion.
Ingestion is the intake of food, which is broken down into simpler organic matters by a process called digestion. After extraction of useful components, the unwanted and undigested particles are excreted out.
Examples of animals that exhibit holozoic nutrition include all vertebrates. Even some unicellular organisms such as amoeba also exhibit holozoic nutrition.
Saprophytic Nutrition
Saprophytes (animals which follow saprophytic nutrition) feed on dead and decayed organisms for energy. They are an important part of the ecosystem as they help to keep our environment clean and recycle nutrient back into the ecosystem.
Some examples of saprophytes are fungi and certain types of bacteria. These are also responsible for the staling of bread and other similar food products.
Saprophytes release certain enzymes to act on the complex organic matter. It works by breaking it down into its constituents, which can be easily consumed by them.
Parasitic Nutrition
Organisms that live in or on other organisms and acquire food at the expense of its host are called parasites. Most parasites are harmful to the hosts’ health; sometimes, they even kill the host. Both animals and plants may serve as a host. Unlike commensalism, the parasite causes some harm to its host. A few examples of parasites are louse on a human head, Cuscuta plant and tapeworms.
Cymothoa exigua is an unusual parasite. It is also known as the tongue-eating louse and is aptly named so as it is found in the mouth of the marine fish Lithognathus. It essentially severs the fish’s tongue, cutting off the blood supply and causing the tongue to fall off. The louse then attaches itself to the remains of the tongue and essentially acts as the fish’s new tongue.