Evolution Class 12 Questions and Answers

NCERT Solution for class 12 Evolution explains evolution that occurred from a common single-celled ancestor to the huge number of single cellular and multicellular organisms we see today. It also gives details on human evolution and the characteristics of our ancestors. Revise the basic concepts of evolution for quick revision and class notes.

Q1: Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.

Answer:

Darwin’s theory of natural selection or Darwinian selection theory emphasizes the fact that nature promotes the survival and reproduction of organisms having suitable adaptation to survive in changing environmental conditions. Like if a particular geographical area submerges in water then nature will promote those organisms which adapt to live in water or find another region to live in. One of the common instances of this phenomenon is the development of antibiotic resistance among many bacterial species. In this phenomenon when an antibiotic is introduced in a medium containing bacterial species, the species which are sensitive to the antibiotic die but in due course some individuals will develop resistivity among them due to mutation that will result in the spread of antibiotic-resistant bacterial colonies in the medium rendering the effect of the antibiotic introduced null.

Q2: Find out from newspapers and popular science articles any new fossil discoveries or controversies about evolution.

Answer:

One of the latest fossil discoveries is the extraction of a woman’s DNA from a 20,000 years old paleolithic artifact discovered in the Denisova Cave of Southern Siberia. Another discovery is the 15-meter-long-necked Jurassic Chinese Sauropod which is known as Mamenchisaurus sinocanadorum in northwestern China. One of the fossilized bird species whose discovery has caused controversy over the evolution of birds is Confuciusornis. They are small crow-sized birds from the early Cretaceous period but unlike other species of birds from that period, this species lacked teeth in their beak. 

Q3: Attempt to give a clear definition of the term species.

Answer:

Species can be clearly defined as a group of organisms that can interbreed among themselves which should result in the production of fertile offspring. 

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

Answer:

Tracing human evolution with its various components will be like this;

1. Dryopithecus Africans have a cranial capacity of around 500 cc and large canines, arms, and legs of equal size. They showed knuckled walking that was similar to gorillas and chimpanzees and preferred eating soft fruits and leaves.
2. Ramapithecus has a cranial capacity of around 500 to 600 cc, small canines, and large molars. They showed semi-erect posture and preferred eating seeds and nuts. 
3. Australopithecus africanus has a cranial capacity of around 450-500 cc, small canines, and small incisors. They showed full erect posture with an approximate height of 1.05 meters, lived in trees, hunted with stone weapons, and preferred eating fruits i.e. were herbivores.
4. Homo habilis has a cranial capacity of around 650 to 800 cc and small canines. They showed fully erect posture with an average height of 1.5 meters, were the first tool makers, and preferred eating meat i.e. carnivorous. 
5. Homo erectus has a cranial capacity of around 900 cc. They showed fully erect posture with an average height of 1.5 to 1.8 meters, used stones and bone tools for hunting games, and were omnivores. 
6. Homo neanderthalnsis has a cranial capacity of around 1400 cc. They showed fully erect posture with an average height of 1.5 to 1.66 meters, were cave dwellers, buried their dead, used hides to protect their bodies, and were omnivorous.
7. Homo sapiens fossils have a cranial capacity of around 1600 cc. They showed fully erect posture with an average height of 1.8 meters, had a strong jaw with closed teeth, were cave dwellers, made paintings and carvings in caves, were omnivores, had a culture, and thus called the first modern man. 
8. Homo sapiens have a cranial capacity of around 1200 to 1600 cc. They show fully erect posture with an average height of around 1.5 to 1.8 meters, are the living modern man, have high intelligence, developed art, culture, language, speech, crop cultivation, are domesticated animals, and are omnivores. 

Q5: Find out through the internet and popular science articles whether animals other than men have self-consciousness.

Answer:

There are many animals other than humans that have shown certain degrees of intelligence or self-consciousness in them like chimpanzees, gorillas, orang-utans, parrots, crows, cats, dogs, dolphins, etc. One example is Chimpanzees can recognize themselves in a mirror or cats grooming themselves from time to time, etc. However, one of the most astonishing examples is the ability to recognize others, and communicate with each other by whistles or tail-slapping in dolphins, this shows that they have a huge level of self-consciousness as well as intelligence. 

Q6: List 10 modern-day animals and using the internet resources link them to a corresponding ancient fossil. Name both. 

Answer:

Ten modern-day animals and their corresponding ancient fossils are;

1. Modern-day man (Homo sapiens sapiens) and their ancient Ramapithecus counterpart.
2. Morden day horse (Equus caballus) and their ancient Eohippus counterpart.
3. Modern-day dogs (Canis familiaris) and their ancient Leptocyon counterpart.
4. Modern-day camel (Camelus) and their ancient Protylopus counterpart.
5. Modern-day elephant (Elephas maximus) and their ancient Moerithers counterpart.
6. Modern-day whales (Balaenoptera musculus) and their ancient Protocetus counterpart.
7. Modern-day fish (Balaenoptera musculus) and their ancient Arandaspis counterpart.
8. Modern-day tetrapods (Tetrapoda) and their ancient Icthyostega counterpart.
9. Modern-day bats (Chiroptera) and their ancient Archaeonycteris counterpart.
10. Modern-day giraffes (Giraffa) and their ancient Palaeotragus counterpart. 

*As per the revised curriculum of CBSE Syllabus 2023-24, this chapter, previously known as Chapter 7, has now been renumbered as Chapter 6. Stay updated with the latest changes in the curriculum.

Evolution Class 12 NCERT Solution is all about the process of Evolution, the benefits of evolution reasons for evolution. These NCERT Solutions are prepared by our Top Biology Experts in order to take care of all Important Topics that might be asked in the upcoming examination 2023. So, Students can also refer to these solutions for their final Examination preparation.

This Class 12 Biology Chapter 6 Evolution NCERT Solutions are carefully developed using easy-to-understand language while adhering to the guidelines for solving NCERT Solutions for Class 12. Working through these solutions can be highly beneficial for students in their board exams, as well as in preparing for future competitive Exams.