CBSE 12TH BIOLOGY - Online Test
Q1. During translation initiation in prokaryotes, a GTP molecule is needed in
Answer : Option A
Explaination / Solution:
During translation initiation in prokaryotes, a GTP molecule is required along with 30S ribosome, m-RNA with formyl-met-t-RNA. GTP provides energy and ribosomes provide site for translation.
Q2. For converting an inferior local breed into superior breed, cross breeding with the same types of superior bull is required for
Answer : Option B
Explaination / Solution:
Local inferior breed of cow is changed into superior breed by Hybridisation methods. In this method superior bull is required to breed for 6-7 generations to get desired traits.
Q3. Sanctuaries, national parks & biosphere reserves are examples of :
Answer : Option D
Explaination / Solution:
In situ conservation is the conservation of organisms in their natural geographic regions by providing protection from poaching, cutting or other similar activities. In sanctuaries, national parks and biosphere reserves organisms are kept in natural habitat.
Q4. The vagina connects the
Answer : Option A
Explaination / Solution:
The vagina is a elastic, muscular tube that connects the cervix of the uterus to the exterior of the body. It is located inferior to uterus and posterior of the urinary bladder.
Q5. In somatic cells of human beings chromosomes exists as
Answer : Option A
Explaination / Solution:
Somatic cells of human beings contain 23 pairs of chromosomes, 23 each from male and female gametes. These chromosomes always occurs as homologous chromosome as contain same kinds of trait.
Q6. The discovery that led to development of first antibiotic was made by
Answer : Option C
Explaination / Solution:
The discovery of first antibiotic was related to A.Flemming observations about the secretion of some chemicals from Penicillium notatum that prohibited the growth of bacteria.
Q7. Potency of injury that can be caused by a radioactive isotope will not depend upon
Answer : Option A
Explaination / Solution:
Radioactive isotopes releases harmful radiations that may cause injury to health. Potency of injury will depends upon its rate of being absorbed or excreted, penetrating ability and its ionizing power and not on the place of availability.
Q8. Elution can be done by using the enzyme
Answer : Option A
Explaination / Solution:
Elution is the process of extracting one material from another by washing with a solvent. Elution can be done by using enzyme agarase that can catalyze the hydrolysis of agar.
Q9. Some ancient organism still survive on earth but most of them have become extinct this is because of
Answer : Option C
Explaination / Solution:
Some ancient organism still survive on earth but most of them have become extinct this is because of presence of characteristic which enable them to survive better in natural conditions.
Q10. Which of the following organism produce gemmules as asexual reproductive structure?
Answer : Option C
Explaination / Solution:
Gemmules are asexual reproductive structure produced by sponges. Chlamydomonas produce zoospores, hydra produce buds and Penicillium produces conidia.
