Biology - Online Test
Q1. If a species experiences a 90 percent decline over 10 years (or three generations), would be classified as :
Answer : Option B
Explaination / Solution:
A critically endangered (CR) species is one which has been categorized by the International Union for Conservation of Nature (IUCN) as facing a very high risk of extinction in the wild.
Criteria for critically endangered is an observed, estimated, inferred or suspected population size reduction of ≥ 90% over the last 10 years or three generations, whichever is the longer, where the causes of the reduction are clearly reversible AND understood AND ceased.
Critically endangered species should be protected to avoid extinction.
Q2. Read the following statements about gestational diabetes :
i. It must be controlled to protect baby’s growth and development.
ii. It puts women at risk for developing Type – 1 diabetes.
i. It must be controlled to protect baby’s growth and development.
ii. It puts women at risk for developing Type – 1 diabetes.
Answer : Option A
Explaination / Solution:
Gestational diabetes develops during pregnancy. It must be controlled to protect baby’s growth and development. This kind of diabetes never leads to develop type-1 diabetes.
Q3. Which among the following is called Portuguese man-of-war?
Answer : Option B
Explaination / Solution:
The Portuguese man-of-war is a siphonophore, an animal that is made up of a colony of organisms working together.Physalia is called Portuguese man-of-war. It is also called as blue bottle or floating terrror it is found floating on water surface. " The name comes from the uppermost polyp, a gas filled bladder, or pneumatophore, which sits above the water and somewhat looks like an old warship at full sail. They are also, known as bluebottles for the purple-blue color of their pneumatophores" (A Portuguese man of war). The tentacles can extend to 165 feet, although, the average length is 30 feet (Portuguese Man-of War Physalia physalis).
Q4. A mature ovarian follicle is called
Answer : Option C
Explaination / Solution:
A mature ovarian follicle is called Graafian follicle which consists of antrum and follicular cells.
Q5. 98% of living body is formed of six elements- C, H,N,O and
Answer : Option C
Explaination / Solution:
Everything in universe is made up of elements. The body of living organisms contain mainly six elements. These are carbon, hydrogen, oxygen phosphorous and Sulphur. In facts, 98% of living body is formed on these six elements.
Q6. Crossing over occurs at
Answer : Option B
Explaination / Solution:
Crossing over occurs at four strand stage of panchytene of meiosis-I. Each homologous chromosome has two stands. Exchange of gene occurs during this period.
Q7. The term antibiotic was coined by
Answer : Option A
Explaination / Solution:
The term antibiotic was coined by Selman Abraham Waksman. He developed antibiotic Streptomycin that cure tuberculosis. He got noble prize in medicine in 1952.
Q8. Each cardiac cycle takes 0.8 seconds to occur. Calculate how many cardiac cycles occur in 4 minutes ?
Answer : Option C
Explaination / Solution:
4 min = 240 sec. Therefore, 240/0.8 = 300 cardiac cycles.
Q9. In electron transport system, the two copper centres are found in
Answer : Option C
Explaination / Solution:
The enzyme cytochrome c oxidase or Complex IV,is a large transmembrane protein complex found in bacteria and the mitochondrion of eukaryotes.
The complex contains two hemes, a cytochrome a and cytochrome a3, and two copper centers, the CuA and CuB centers. The cytochrome a3 and CuB form a binuclear center that is the site of oxygen reduction.
Q10. The biological amplification of DDT in the various trophic levels is known as
Answer : Option A
Explaination / Solution:
Biomagnification, also known as bioamplification or biological magnification, is the increasing concentration of a substance, such as a toxic chemical, in the tissues of organisms at successively higher levels in a food chain.
The biological amplification of DDT in the various trophic levels is known as biomagnifications.
