Fossils up to 75,000 years old can be dated with Carbon-14.
Radio isotopes can be used for the age determination of the fossils. Carbon-14 is a common isotope which is used for that purpose. But the half- life of the Carbon-14 is relatively small as 5730 years. That means the amount of Carbon-14 will be half after every 5730 years. Hence, decay is very fast. So Carbon-14 cannot be used forage determination which is more than 75000 years due to the low accuracy.
Answer:
Magnesium, calcium, phosphorous, sulfur these are essential nutrients for plants. These are required in trace quantity but are very important for plant life. Point A. will be correct answer.
Explanation:
As in B. starch n cellulose are composed of only carbon, oxygen and hydrogen.
As in C. These elements are not required on special occasion but are necessary throughout plant life.
As in D. C H N O is the primary component plants need but these secondary nutrients are equally necessary for growth n structure of plant.
<u><em>So answer A. Is the correct option.</em></u>
Calcium plays the most important role in structure formation of plants. Also act as messenger molecule in signaling. Deficiency of calcium caused wilting , weakened stem and ultimately death of plant.
Magnesium is the key element in chlorophyll molecule. It is necessary for chlorophyll formation.
Sulfur is another very important element in plant life, it is necessary for protein synthesis in plants.
Phosphorous plays an important role in process of cell devision , photosynthesis and respiration.
Potassium is very crucial in gaseous exchange ,it operates the opening and closing of stomata.
Answer:the phloem transports food and nutrient
Explanation:
