Biology - Online Test
Q1. An age pyramid showing declining population is
Answer : Option A
Explaination / Solution:
Age pyramids having declining population is referred as contracting pyramid or orion pyramids or Urn pyramids. This kind of pyramids is formed by population having more old aged population than young age population.
Q2. Most active nitrogen fixer in Rice field is
Answer : Option C
Explaination / Solution:
Rice field contains large number of nitrogen fixing algae and bacteria. In which Aulosira fertilissima is most active nitrogen fixer in the rice field.
Q3. The arrows represent :[upward to downward]
Answer : Option C
Explaination / Solution:
The figure shows the muscular sac called the gall bladder. The duct of gall bladder (cystic duct) along with the hepatic duct from the liver forms the common bile duct.
Q4. Which of the following provides physiological barrier as innate immunity?
Answer : Option B
Explaination / Solution:
Physiological barrier is a kind of innate immunity which prevents microbial growth in the body that causes infection. Acid in stomach kill the microbes that enters the alimentary canal along with food.
Q5. In the following identify from up to down :
(i)&(ii)
(iii) & (iv)
(i)&(ii)
(iii) & (iv)
Answer : Option B
Explaination / Solution:
The reflex pathway comprises at least one afferent neuron (receptor) and one efferent (effectoror excitor) neuron appropriately arranged in a series. The (iii) and (iv) shows gray and white matter.
Q6. On germination, moss spore produce
Answer : Option D
Explaination / Solution:
The spore of moss germinate to produce protonema, which is a green, branched and frequently filamentous stage and develops a lateral bud which is called as secondary protonema or a leafy stage.Secondary protonema also gives rise to gametophore initials. Secondary protonema can undergo both sexual and asexual modes of reproduction. It reproduces asexually by the processes of budding and fragmentation. Sexual reproduction is the process which occurs in the leafy stage.
Q7. Which does not occur in cell membrane?
Answer : Option D
Explaination / Solution:
Cell membrane consists of phospholipids and protiens. Some cells also contain praline and cholesterol but glycolipid is not present in cell membrane.
Q8. Copying of DNA to make more DNA copies is called DNA replication. Replication occurs by method of
Answer : Option A
Explaination / Solution:
In semiconservative replication, when the double stranded DNA helix is replicated, each of the two new double-stranded DNA helices consisted of one strand from the original helix and one newly synthesized. It has been called "the most beautiful experiment in biology.
Semi-conservative replication of DNA was proved by the Meselson and Stahl in 1958.
Q9. Correct decreasing order for rate of primary productivity on land will be
Answer : Option B
Explaination / Solution:
Primary productivity is maximum in tropical rain forests due to availability of sufficient food and water followed by temperate forests. Savannah grasslands have comparatively less productivity and arid regions have limited biotic component and water.
Q10. The substances like ATP carry energy in
Answer : Option D
Explaination / Solution:
Living organisms have the capability of extracting energy from oxidisable substances and store this in the form of bond energy. Special substances like ATP, carry this energy in their chemical bonds.
