Question

A total root parasite is
a. Dendrophthoe
b. Orobanche
c. Viscum
d. Santalum

Answer 1

Hint: Generally, plants are photoautotrophs, but some plants, depend on food and water on other living plants are called parasitic plants, and among all plants, 1% of angiosperms constitutes the parasitic plants, and they almost found in every biome.

Complete answer:
- Parasitic plants have special roots that are modified to penetrate the host plant, and those roots are called Haustoria.
- These haustoria penetrate the roots of other plants and connect to conducting vessels, either xylem or phloem.

Depending on where the roots are attached, these parasitic plants had classified into many types:
- Stem parasite: If the parasitic plants attach to the stem of the host, then it is called a stem parasite.
- Root parasite: If the parasitic plants attach do the root of the host, then it is called as a root parasite
- Obligate parasite: If a parasite does not complete the life cycle without the presence of a host, then it is called an obligate parasite.
- Facultative parasite: If a parasite is able to complete its life cycle by its own, and it is independent then it is called a facultative parasite.
- Hemiparasite: The plants which can undergo photosynthesis to some degree, and some it depends on the host for water and nutrients, is called hemiparasite.
- Holoparasite: The plants which obtain all the fixed carbon from the host plant, usually these parasitic plants lack the chlorophyll for photosynthesis.

So among the above-given options:
Dendrophthoe is the hemiparasite
Orobanche is the complete root parasite.
Viscum is the stem hemiparasite.
Santalum is the root hemiparasite.

Hence, the correct answer is option (B).

Note: Orobanche is the genus of 200 species of the plant, which is parasitic, these plants do not have chlorophyll, so it completely depends on host plants, where the roots of this plants, penetrate the phloem of the host plants, so that it obtains all the food, minerals, and water, etc.