CBSE 12TH BIOLOGY - Online Test
Q1. Diversity can be promoted by:
Answer : Option C
Explaination / Solution:
The species that predominates in an ecological community, particularly when they are most numerous or form the bulk of the biomass.
Diversity can be promoted by dominant species. Dominant species of an ecosystem determine the way of diversity which may be linear or diverse.
Q2. Primary germ layers are
Answer : Option A
Explaination / Solution:
Development of fetus start from zygote divisions to form embryo. The embryo undergoes multiple divisions to form blastocysts that arrange into layers. The primary layers are ectoderm, mesoderm and endoderm.
Q3. Whose karyotype is represented below?
Answer : Option B
Explaination / Solution:
Karyotype is the representation of chromosome in order of shape and size. Male Drosophila fly have 3 pairs of autosomes and 1 pair (XY) sex chromosome.
Q4. Organism like Escherichia coli and Chlamydia trachomatis fall into which domain?
Answer : Option D
Explaination / Solution:
Escherichia coli and Chlamydia trachomatis fall into which Bacteria family. Bacteria can live in all kind of environment like air, water and soil including inside the body of plants and animals as parasite.
Q5.
ECOSAN (compost toilets) is about
(i) minimising unnecessary water use
(ii) household and personal hygiene
(iii) maximising recycling and reuse at domestic level of grey water
Answer : Option C
Explaination / Solution:
Ecological sanitation (Ecosan) is a concept that treats various types of waste generated by us as a resource which can be safely collected, treated and reused to prevent pollution of water bodies and the environment.
It minimize unnecessary water use, house hold and personal hygiene and maximizing recycling and reuse at domestic level of grey water.
Q6. The palindromic sequence out of the given options is
Answer : Option D
Explaination / Solution:
Palindromic sequence is the sequence which reads same from left to write or from right to left. MADAM is an example of palindromic sequence.
Q7. What was the resultant found in place marked E?
Answer : Option C
Explaination / Solution:
In Urey and Miller’s experiment the product formed after the continuous sparking in the mixture of gases at high temperature were some amino acids like glycine and alanine. Sugar and nitrogenous base were also obtained from same set up by some other scientist.
Q8. 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
Q9. 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.
Q10. 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.
