Biology - Online Test
Q1. High value of BOD shows
Answer : Option A
Explaination / Solution:
Biological oxygen demand is the amount of oxygen required to completely decompose the organic waste present in one liter of water by bacteria. High value of BOD shows that water is highly polluted.
Q2. If DDT content in the water of a lake is found to be 0.004 ppm then pelicans of that area will have:
Answer : Option A
Explaination / Solution:
DDT is used as pesticide in crop fields and to kill mosquito in open drains. DDT is not a biodegradable and reaches to nearby water bodies. DDT enters the food chain through aquatic organisms and get magnified at each trophic levels. Pelicans beings at higher trophic levels may contain upto 2 ppm DDT.
Q3. In Ocimum sanctum(tulsi), stem is
Answer : Option A
Explaination / Solution:
The stem of Oscimum sanctum or tulsi is quadrangular in shape. The stem is covered with hairy projection.
Q4. How many meiotic divisions are required to form 64 pollen grains
Answer : Option A
Explaination / Solution:
Each microspore mother cell produces four pollen grains by reduction division. Hence to produce 64 pollen grains 16 meiotic or reduction division is required.
Q5. Multinucleate condition arise when Cytokinesis does not follow karyokinesis, this type of cells are called as
Answer : Option D
Explaination / Solution:
Karyokinesis is followed by cytokinesis but some times cytokinesis is not followed by karyokinesis which leads to the establishment of multinucleate condition. This type of cells are called as coenocytes.
Q6. Eco RI acting on goi and vector will produce
Answer : Option C
Explaination / Solution:
Restriction enzymes, such as EcoRI, are used in a wide variety of molecular genetics techniques including cloning, DNA screening and deleting sections of DNA in vitro. Restriction enzymes, like EcoRI, that generate sticky ends of DNA are often used to cut DNA prior to ligation, as the sticky ends make the ligation reaction more efficient.
Q7. Conditional reabsorption of sodium ions and water takes place in
Answer : Option D
Explaination / Solution:
Distal Convoluted Tubule (DCT): Conditional reabsorption of Na+ and water takes place in this segment. DCT is also capable of reabsorption of HCO3- and selective secretion of hydrogen and potassium ions and NH3 to maintain the pH and sodium-potassium balance in blood.
Q8. Which one of the following is incorrect about the characteristics of protobionts (coacervates and microspheres) as envisaged in the abiogenic origin of life?
Answer : Option B
Explaination / Solution:
Protobionts that include coacervates and microspheres are involved in origin of life from inorganic substance. Coacervate and microspheres are separate combinations of molecules from surroundings that leads to formation of first life on earth.
Q9. Jute fibers deteriorate because they have
Answer : Option A
Explaination / Solution:
Jute fibers are made of high amount of lignin that deteriorate in presence of high moisture and water,
Q10. Mathematically arithmetic growth is expressed as
Answer : Option C
Explaination / Solution:
Arithmetic growth is represented by where Lt is final growth, Lo is initial size and rt is the rate of growth and time respectively.
