Question
Which element is responsible for causing soil salinity? At what concentration does the soil become saline?
✓
Answer
Minerals are responsible for causing soil salinity. Following are some of the cause for increase in soil salinity:
- High level of salt in soil.
- Water table movement because of landscape features.
- Human activities; like clearing of land and excess use of synthetic fertilizers.
- Salt runoff from streets can happen in cold climates because salt is applied on road to prevent snow accumulation.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Describe the difference between the structures of a dicot embryo and monocot embryo. Also draw LS of monocot and dicot seeds.
With a neat, labelled diagram, describe the parts of a typical angiosperm ovule.
Describe the model of phosphorus cycle in the terrestrial ecosystem.
A child suffering from thalassemia is born to a normal couple. But the mother is being blamed by the family for delivering a sick baby.
- What is thalassemia?
- How would you counsel the family not to blame the mother for delivering a child suffering from this disease? Explain.
- List the values your counselling can propagate in the families.
“Phenylketonuria is a good example that explains Pleiotropy.” Justify.
Explain the efforts for the conservation of biodiversity at international level.
Polymerase chain reaction (PCR) is a laboratory technique used to amplify DNA sequences. The method involves using short DNA sequences called primers to select the portion of the genome to be amplified. The temperature of the sample is repeatedly raised and lowered to help a DNA replication enzyme copy the target DNA sequence. The technique can produce a billion copies of the target sequence in just a few hours.
i. List the three steps involved in Polymerase Chain Reaction (PCR).
ii. Name the source organism of Taq polymerase.
iii. Explain the specific role of this enzyme in PCR.
i. List the three steps involved in Polymerase Chain Reaction (PCR).
ii. Name the source organism of Taq polymerase.
iii. Explain the specific role of this enzyme in PCR.
In 1952, Alfred Hershey and Martha Chase took an effort to find the genetic material in organisms. Their experiments led to an unequivocal proof to DNA as genetic material.
Answer the following questions based on Hershey and Chases's experiments:
i. Name the kind of virus they worked with and why?
ii. Why did they use two types of culture media to grow viruses in? Explain.
iii. What was the need for using a blender and later a centrifuge during their experiments? OR
iv. State the conclusion drawn by them after the experiments.
Answer the following questions based on Hershey and Chases's experiments:
i. Name the kind of virus they worked with and why?
ii. Why did they use two types of culture media to grow viruses in? Explain.
iii. What was the need for using a blender and later a centrifuge during their experiments? OR
iv. State the conclusion drawn by them after the experiments.
Trace the events that would take place in a flower from the time the pollen grain of the same species falls on the stigma up to the completion of fertilisation.
Elaborate how invasion by an alien species reduces the species diversity of an area.