Biology - Online Test
Q1. Which of the following hormone is used to kill dicotyledonous weeds?
Answer : Option C
Explaination / Solution:
2, 4 D (2,4-Dichlorophenoxyacetic acid)are widely used as herbicides. It is widely used to kill dicotyledonous weeds, does not affect mature monocotyledonous plants.
Q2. Find the correct order of vegetative propoagules in potato, ginger Bryophyllum and water hyacinth
Answer : Option B
Explaination / Solution:
Potato tubers have eyes, ginger propagates through underground rhizome, Bryophyllum leaves have buds and water hyacinth propagates by offset stem. All these structures are mode of asexual reproduction
Q3. The ecological niche of an organism will not represent
Answer : Option B
Explaination / Solution:
Ecological niche is the area surrounding an organisms that help them in survive, grow and reproduce.
The ecological niche of an organism represents the position and the role played by the organism in the ecosystem in which it lives.
The ecological niche of an organism will not represent resources it cannot utilize.
Q4. In the following two graphs :
i.first graph shows: twitch summation etanus fatigue.
ii. second graph shows: incomplete and complete tetanus.
i.first graph shows: twitch summation etanus fatigue.
ii. second graph shows: incomplete and complete tetanus.
Answer : Option C
Explaination / Solution:
Graph 1 shows muscle fiber tension with time. Which occurs in order as : twitch→summation→tetanus→fatigue.
Graph 2 shows complete and incomplete tetanus. Tetanus is also known as lockjaw, which is a infection characterized by muscle spasm.
Q5. Full form of GMO is
Answer : Option C
Explaination / Solution:
GMO is an abbreviation for genetically modified organism, an organism whose genetic material has been modified, especially by genetic engineering.
Q6. Saheli is
Answer : Option A
Explaination / Solution:
Saheli is an oral contraceptive for females contain non-steroidal preparation. It is different from the other pills as it should be taken once in a week irrespective of daily in case of other pills.
Q7. Which one is a heterocrine gland?
Answer : Option A
Explaination / Solution:
Pancreas is called as heterocrine gland because it acts as both endocrine and exocrine gland to secrete hormone as well as digestive enzymes. Testis and Ovary are also heterocrine glands.
Q8. When a fresh water protozoan is placed in marine water
Answer : Option B
Explaination / Solution:
When fresh water protozoan is placed in marine water, the contractile vacuole disappear because the function of vacuole is to expel out excess water but in case of marine water, the water should be retained instead of getting expelled. If the contractile vacuole will not disappear the cell will get dehydrated.
Q9. Rupture and fractionalization of water column present in treachery elements does not occur during ascent of sap due to
Answer : Option A
Explaination / Solution:
Cohesion and adhesion between wall of tracheid and water molecule prevent rupture and fractionalization of water column present in treachery elements during ascent of sap.
Q10. Primary endosperm cell (PEC) is triploid (3n) structure as it is formed by
Answer : Option C
Explaination / Solution:
Primary endosperm cell is triploid because it is formed by fusion of two polar nuclei and one male gamete called triple fusion. Primary endosperm cells divides further to form endosperm that provide nourishment to embryo.
