Class 12 Biology Chapter 7 Evolution Question Answer

 Chapter 7 

  Evolution 

Q1. Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.
Ans: According to Darwinian theory, the individuals with suitable variations can adapt in changing environment. When bacterial population was grown on a agar plate having antibiotic penicillin, some of the bacteria colonies died, as they were sensitive to penicillin. But there were some colonies which survived as they were resistance to penicillin. This occurs due to the mutation which made them resistant to penicillin and cause evolution of a gene.



Q2. Find out from newspapers and popular science articles any new fossil discoveries or controversies about evolution.
Ans: in here we have to search articles in newspapers about the new discoveries of fossil.



Q3. Attempt giving a clear definition of the term species.
Ans: Species refer as the group of organisms that have the ability to reproduce offspring by the process of interbreeding.



Q4. Try to trace the various components of human evolution (hint; brain size and function, skeletal structure, dietary preference, etc.)
Ans: The various components of human evolution are –

Drypithecus and Ramapithecus
  • They wear hairy appearance like gorillas and chimpanzees.
  • They walk like gorillas.
  • Ramapithecus was man-like but Drypithecus was ape-like.

Homo habilis-
  • Brain capacities were between 650-800cc
  • They did not eat meat.


Homo erectus-
  • The brain capacity is around 900cc.
  • They generally eat meat.

Homo sapiens fossils -
  • The brain capacity is 1400cc
  • Strong jaws with closer teeth
  • They used clothes composed of animal skin to cover their bodies.
  • They had developed cave art.

Homo sapiens sapiens-
  • They are the intelligent creature on Earth.
  • Developed language, art and culture.
  • Human settlement starts
  • Cultivates plants



Q5. Find out through internet and popular science articles whether animals other than man have self- consciousness.
Ans:  In here you have to find out the animals other than man that have self-consciousness. For example- dolphins.

 

Q6. List 10 modern-day animals and using the internet resources link it to a corresponding ancient fossil. Name both
Ans: in here, you have to list 10 modern animals link to ancient fossil with the help of internet. For example-

Modern-day animal     Ancient fossil

Man                            Ramapithecus

 


Q7. Practice drawing various animals and plants.
Ans:  draw various animals and plants with the help of you book.

 

Q8. Describe one example of adaptive radiation.
Ans: Darwin observed in Galapagos Islands that there is amazing diversity of creatures. He found that there are different varieties of finches which were evolved on the island itself. The beaks of the finches were altered from seed-eating features to vegetarian finches which help them to suit their eating habits. In order to feeding habits they have evolved from single seed eating finches ancestors.

 

Q9. Can we call human evolution as adaptive radiation?
Ans: No, human evolution cannot be called adaptive radiation as it is an evolutionary process that generates new species from a single ancestor. But human population is a  progressive process that occurred slowly in time.

 

Q10. Using various resources such as your school library or the internet and discussions with your teacher, trace the evolutionary stages of any one animal say horse.
Ans: in here you have to search an animal evolutionary stage, example horse with the help of school library or internet.


Dipshikha Das



Post Id: DABP001070