Phosphorus Cycle MCQs and Answers

Are you looking for Phosphorus Cycle MCQs and Answers for medical entrance examinations? If yes, these are some most important multiple choice questions and answers on NCERT Class-12 Biology, Chapter-14 (Ecosystem).

Here we composed these Phosphorus Cycle MCQs and Answers after reading the chapter on Ecosystem from the NCERT book on Class 12 Biology. The questions are topics-wise and the students can relate the questions easily to the most important topics of this chapter.

Phosphorus Cycle MCQs and Answers

1. Which one of the following is a major constituent of biological membranes, nucleic acids, and cellular energy transfer systems?

a) Potassium

b) Phosphorous

c) Selenium

d) Cobalt

Answer: b


2. Which of the following component is used to make shells, bones, and teeth by animals?

a) Phosphorous

b) Sodium

c) Gallium

d) Argon

Answer: a


3. Who is the natural reservoir of phosphorous?

a) Atmospheric gases

b) Rocks

c) Water

d) Dead organisms

Answer: b


4. Which element is not released during respiration in the atmosphere?

a) Nitrogen

b) Cobalt

c) Carbon

d) Phosphorous

Answer: d


5. How is the gaseous exchange of phosphorus between organisms and the environment?

a) Maximum

b) Moderate

c) Negligible

d) No exchange

Answer: c


6. Which one of the following is the simplified sequence of phosphorus cycling in a terrestrial ecosystem?

a) Soil → Producers → Rock minerals → Consumers → Decomposers

b) Rock minerals → Soil → Producers → Consumers → Decomposers

c) Rock minerals → Decomposers → Producers → Consumers

d) Decomposers → Rock minerals → Consumers → Producers

Answer: b


7. How do herbivores and other animals obtain phosphorous?

a) Soil

b) Rocks

c) Water

d) Plants

Answer: d


8. Which of the biochemical cycle is without an atmospheric component?

a) Nitrogen cycle

b) Oxygen cycle

c) Phosphorous cycle

d) Carbon cycle

Answer: c


9. Which of the following is a major constituent of DNA and RNA?

a) Calcium

b) Cobalt

c) Selenium

d) Phosphorous

Answer: d


10. Which biogenetic element is obtained from crystalline rocks?

a) Argon

b) Helium

c) Phosphorous

d) Magnesium

Answer: c


11. Which of the following is known as the natural reservoir of phosphorous?

a) Fossils

b) Rocks

c) Animals

d) Water

Answer: b


12. The phosphate by weathering of rocks firstly becomes available to which organisms?

a) Decomposers

b) Consumers

c) Producers

d) Detritivores

Answer: c


13. In which form do the producers directly provide phosphorous to detritus?

a) Weathering

b) Litterfall

c) Fecal matter

d) Salts

Answer: b


14. What is the killing of aquatic life due to the depletion of oxygen because of the excessive growth of algae due to the over-abundance of phosphorous in the coastal areas called?

a) Leaching

b) Respiration

c) Photosynthesis

d) Eutrophication

Answer: d


If you’re anything like me, you probably have a lot of questions about the phosphorus cycle. Here are a few of the most frequently asked questions that I’ve come across:

FAQs on Phosphorus Cycle

1. What is the phosphorus cycle?

Answer: The phosphorus cycle is the natural process by which phosphorus is circulated through the environment. Phosphorus is an essential element for plant and animal life, and the phosphorus cycle ensures that it is available in the right quantities.

2. How does the phosphorus cycle work?

Answer: The phosphorus cycle starts with phosphorus-containing minerals in the earth’s crust. These minerals are gradually broken down by weathering and erosion, and phosphorus is released into the environment. Plants absorb phosphorus from the soil and use it to grow. Animals eat plants and absorb phosphorus. When animals excrete phosphorus, it is returned to the environment. Phosphorus can also be released into the environment through volcanic eruptions and other geological processes.

3. What are the benefits of the phosphorus cycle?

Answer: The phosphorus cycle is essential for life on earth. Phosphorus is a key nutrient for plants, and the phosphorus cycle ensures that it is available in the right quantities. The phosphorus cycle also helps to purify the environment by removing excess phosphorus from the ecosystem.

4. What are the challenges of the phosphorus cycle?

Answer: One of the challenges of the phosphorus cycle is that it is slow. Weathering and erosion can take centuries to release phosphorus into the environment. This can create problems if there is a sudden need for phosphorus, such as during a period of rapid population growth. Another challenge is that the phosphorus cycle can be disrupted by human activities, such as mining, agriculture, and pollution.

Have any other questions about Phosphorus Cycle? Leave a comment below and we’ll do our best to answer them!

Comments