Plant Pathology - Study Mode
[#446] Carbon dioxide is fixed in
Correct Answer
(B) Dark reaction
Explanation
Solution: Carbon dioxide is fixed in the Dark reaction. The dark reaction occurs outside of the thylakoids. In this reaction, the energy from ATP and NADPH is used to fix carbon dioxide (CO 2 ). The products of this reaction are sugar molecules and other organic molecules necessary for cell function and metabolism. Carbon dioxide is fixed, that is, removed from the atmosphere and incorporated into a small, water-soluble carbohydrate in the dark reactions of photosynthesis.
[#447] The experimental material that has largely been responsible for making rapid advances in research on photosynthesis is
Correct Answer
(B) Chlorella
Explanation
Solution: The experimental material that has largely been responsible for making rapid advances in research on photosynthesis is Chlorella. Chlorella is a genus of about thirteen species of single-celled green algae belonging to the division Chlorophyta. In 1961, Melvin Calvin of the University of California received the Nobel Prize in Chemistry for his research on the pathways of carbon dioxide assimilation in plants using Chlorella. The experimental research was carried out in laboratories, rather than in the field, and scientists discovered that Chlorella would be much more difficult to produce than previously thought.
[#448] Green manures are mostly used as a source of
Correct Answer
(D) Nitrogen
Explanation
Solution: Green manures are mostly used as a source of Nitrogen. Green manuring is often used with legume crops to add nitrogen to the soil for following crops, especially in organic farming, but is also used in conventional farming. Depending on the species of cover crop grown, the amount of nitrogen released into the soil lies between 40 and 200 pounds per acre. With green manure use, the amount of nitrogen that is available to the succeeding crop is usually in the range of 40 - 60% of the total amount of nitrogen that is contained within the green manure crop.
[#449] The sexual, thick walled and resting spores of the rust fungi is known as
Correct Answer
(C) Teliospores
Explanation
Solution: The sexual, thick-walled, and resting spores of the rust fungi are known as Teliospores. Teliospore cells are both thick-walled and pigmented allowing them to remain dormant throughout winter before germinating the following spring to produce short-lived, thin-walled basidiospores. Teliospores function to shield genetic material during the stresses of dispersal between host plants.
[#450] Black rust or stem rust of wheat is caused by
Correct Answer
(A) Puccinia graminis tritici
Explanation
Solution: Black rust or stem rust of wheat is caused by Puccinia graminis tritici. Stem rust, also known as cereal rust, black rust, red rust, or red dust, is caused by the fungus Puccinia graminis, which causes significant disease in cereal crops. Crop species that are affected by the disease include bread wheat, durum wheat, barley, and triticale. Stem rust on wheat is characterized by the presence of uredinia on the plant, which are brick-red, elongated, blister-like pustules that are easily shaken off.