CBSE 12TH BIOLOGY - Online Test
Q1. Mitotic division in zygote as it moves through the isthmus of oviduct is called
Answer : Option A
Explaination / Solution:
Zygote undergoes mitotic division as it moves through the isthmus of oviduct by cleavage to form 2, 4,8,16 blastomeres.
Q2. The difference between Homo sapiens and the Homo erectus was
Answer : Option B
Explaination / Solution:
Home sapiens and Homo erectus in differ in their size of brain capacity. The size of brain of Homo erectus was smaller than Homo sapiens.
The average brain size of Homo erectus is estimated to have been roughly 900 cubic centimeters whereas the average brain size capof Homo sapiens is roughly 1300 cubic centimeters.
Q3. DNA fingerprinting is the basis of paternity testing in case of dispute because
Answer : Option D
Explaination / Solution:
Polymorphism is variation at genetic level which occurs due to mutation. Polymorphisms are inheritable from parent to children without any changes so DNA fingerprinting is the basis of paternity testing.
Q4. Finger-like projections appear on the trophoblast after implantation is called
Answer : Option C
Explaination / Solution:
After implantation of blastocysts, finger-like projections appear on the trophoblast called chronic villi which is surrounded by the uterine tissue and maternal blood.
Q5. The first human-like creature being the hominid was called
Answer : Option A
Explaination / Solution:
The first human like creature being hominid was called Homo habilis. Their brain capacity were about 650-800cc and probably do not eat meat.
Louis Leakey, the British-Kenyan paleoanthropologist who was the first to suggest the existence of H. habilis, and his wife, Mary Leakey, found the first trace of H. habilis in 1955: two hominin teeth.
Q6. The sensitivity of fingerprinting technique has been increased by use of
Answer : Option C
Explaination / Solution:
The sensitivity of fingerprinting technique has been increased by use of Polymerase chain reaction (PCR). After that single cell obtained from organism is enough for this technique.
Q7. Inner cell mass (embryo) contain certain cells that contain cells called stem cells which have potency to
Answer : Option A
Explaination / Solution:
The inner cell mass contain certain cells that contain cells called stem cells which have potency to give rise all the tissues and organs. Now a day’s stem cells are preserved for future use.
Q8. Which of the following sentences is true about the evolutionary process?
Answer : Option A
Explaination / Solution:
Evolutionary process is totally different from human progress.
Evolution leads to creation of complex organism. It does not lead to creation of better organism. For e.g, we are not better than the amoeba, we are just complex than amoeba.
There is no real progress in the idea of evolution which is biologically controlled to creation of variation.
Q9. DNA fingerprinting or genetic finger printing is the process of
Answer : Option C
Explaination / Solution:
VNTR analysis (sometimes called DNA fingerprinting) can be used to identify and match cell samples.
In order to use VNTRs, we must have a source of DNA. The DNA can come from any nucleated cell, e.g., white blood cells, skin samples, semen samples, or hair folicles. Red blood cells cannot be used as they do not have a nucleus.
For a VNTR analysis, the DNA is extracted and cut using restriction endonucleases. A Southern Blot is then performed using various probes.
Q10. Which of the following is formed first out of the following in growing foetus
Answer : Option A
Explaination / Solution:
The heart is formed first in foetus after one month of pregnancy. Limbs and digits after second months, limbs and external genital organs after three months and eye lids and hair after six months.
