Question

The first petroplant discovered by Calvin was-
a. Copaifera longsdorfii
b. Euphorbia lathyrus
c. Jatropa
d. Calotropis

Answer 1

The genus of plant is generally referred to as caper spurge or paper spurge and mole plant, a species of spurge native to southern Europe, north western Africa, etc. It is widely naturalised in many countries, away from its native range, where it is also considered an invasive weed.

Complete answer:

Option A is incorrect. Copaifera langsdorffii is a tropical rainforest species, sometimes referred to as the diesel species. The tree is medium to large, with white flowers and tiny, oily fruits. Due to its porosity, the wood is light and it is honeycombed with oil filled capillaries. Tapping the tree requires cutting a well into which the oil seeps and where it can be gathered quickly. Outside of the tropics, the tree does not grow well.

Option B is correct. Calvin's work on petro plants began in 1977. Petroplants create latex that can be converted into petrol-like products from long hydrocarbon chains. He's been working on Euphorbia lathyris. He noticed long chain hydrocarbons similar to petrol and other fuels when he obtained latex from the samples and studied its composition through various methods such as spectroscopy and chromatography. Euphorbia produces vast amounts of latex that, like gasoline, is refined and converted to petrol.

Option C is incorrect. Jatropha is a genus in the spurge family, Euphorbiaceae, of flowering plants. Commonly referred to as nettlespurge or physics nut. The Jatropha Curcas oil is primarily converted to biodiesel for diesel engine use. For fish or animal feed (if detoxified), a cake resulting from oil extraction, a protein-rich product, may be used. It is also a biomass feedstock and a high-quality organic fertiliser for powering energy plants or generating biogas. In basketmaking, tanning and dye production, Jatropha species have historically been used.

Option D is incorrect. In the Apocynaceae family, Calotropis is a genus of flowering plants. It is native to North Africa and southern Asia. Because of the latex they produce, they are commonly known as milkweeds. In some parts of the world, species of Calotropis are considered common weeds. Latex contains a high hydrocarbon content and the ratio of C and H is similar to that of crude oil, petrol and gasoline.

Hence, the correct answer is option (B).

Note: The whole E. lathyrus plants parts are poisonous, including their seeds and roots. As the plant produces latex, handling can cause skin irritation. While poisonous to humans and most animals, often goats eat it and are resistant to the toxin. The toxin can be transmitted through the milk of the goat, however. It is used as a treatment for cancer, maize, and warts in folk medicine, and has been used by beggars to cause skin boils.