Question

Which one of the following is a partial root parasite?
A. Balanophora
B. Santalum
C. Viscum
D. Cuscuta

Answer 1

Hint: A parasite is an organism that derives food and nutrients from another organism.

Complete answer:
Root parasite is the parasite that attaches to the host-parasite.
Root parasite is of two types:
1. Total root parasite – it is a parasite that depends solely on other plants by obtaining nourishment from them. They have haustoria that suck nutrients from the roots of other plants.
2. Partial root parasite – it is a parasite that partially depends on other plants or hosts. They obtain their food by performing photosynthesis on their own but depend on their host for the requirements of other substances.
Santalum album is a partial root parasite because it photosynthesizes its food, but taps the roots of other species for water and inorganic nutrients, so it depends only partially on the host.
It grows on the roots of Dalbergia, Eucalyptus, and Albizzia.

Additional information
1. Santalum is Indian sandalwood, which is best known and commercially valuable.
2. The best host plant for sandalwood to survive and grow is nitrogen-fixing trees, especially the wattles (Acacia species).
3. Out of 15 different species of sandalwood that grow throughout the world, 2 main varieties are traded internationally.

So, the correct answer is Santalum.

Note: Partial parasites are of different types:
Partial root parasite – the parasite depends partially on their host.
Partial stem parasite – depends upon the host plant only for water and minerals and stays on the host stem. Example – Viscum