CBSE 12TH BIOLOGY - Online Test
Q1. 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.
Q2. 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.
Q3. The death rate if 8 individuals in a laboratory population of 40 fruit flies died during a particular week will be:
Answer : Option C
Explaination / Solution:
Death rate of a population =
Here death rate =
Hence, death rate of fruit fly died is equal to 0.2.
Q4. Which one of the following is a matching pair of a drug and its category?
Answer : Option D
Explaination / Solution:
Amphetamines is kind of drug which is used as stimulant. It is a strong CNS stimulant that is used in the treatment of ADHD. Lysergic acid dimethyl amide is not a narcotic and heroin is not a psychotropic agent.
Q5. Central dogma of protein synthesis is
Answer : Option A
Explaination / Solution:
Central dogma of protein synthesis consists of transcription and translation. In transcription process, DNA is changed into mRNA and in translation step m-RNA produce specific protein.
Q6. One of the alternate sources of proteins for animal and human nutrition is
Answer : Option A
Explaination / Solution:
Protein requirement for human beings can be fulfilled by single cell protein in which algae like Spiruline is grown on large scale having high protein contents.
Q7.
If the outermost circle in the shown figure indicates manipulative zone of biosphere reserve then 1& 2 represent:
Answer : Option A
Explaination / Solution:
Biosphere reserves are divided into a number of zone. The outer most circle of biosphere represent manipulative zone followed by buffer zone and core zone respectively from outside to inside.
Q8. Scrotal sacs of man and rabbit are connected with the abdominal cavity by
Answer : Option B
Explaination / Solution:
Scrotal sac contains testes in male. Scrotal sacs are connected with the abdominal cavity by inguinal canal which is a passage in the anterior abdominal wall which in man conveys the spermatic cord.
Q9. The phenomenon of exchange of segments of chromosome between paternal and maternal chromosome is called
Answer : Option C
Explaination / Solution:
The exchange of segments of chromosome between homologous chromosomes during reduction division is called crossing over. It creates variation in the individuals of same parents.
Q10. Which one of the following is used as biological insecticide?
Answer : Option D
Explaination / Solution:
Tiger beetle is a large group of beetles known for their aggressive predatory habits and running speed. They are used as biological insecticides in organic farming practices.
