Students, you may need to practice a lot while preparing for CBSE board exams and other exams. Isn’t it worth your time? So, what are you waiting for? Download your free set of important CBSE questions along with the solutions now!
Important questions based on NCERT syllabus for Chapter 7 - Evolution:
Question-1: Find out from newspapers and popular science articles any new fossil discoveries or controversies about evolution.
Solution: Chimps are more evolved than humans (The Times of India):
Chimpanzees are more evolved than humans, a study suggests. There is no doubt that humans are the more advanced species. But a comparison of 14,000 human and chimpanzee genes shows the forces of natural selection have and the greatest impact on our ape cousins.
The researchers’ discovery challenges the common assumption that our large brains and high intelligence were the gifts of natural selection. Humans and chimps followed different evolutionary paths from a common ape ancestor about 5 million years ago. Both underwent changes as the fittest survived to pass their genes on to future generations. But the US study shows that humans possess a ‘substantially smaller’ number of positively-selected genes than chimps.
Question-2: List 10 modern-day animals and using the” internet resources link it to a corresponding ancient fossil. Name both.
Solution: (i) Cockroach, Limulus (king crab), Neopilina, Latimaria (Fish) are fossil that has remain unchanged over years.
(ii)’Trilobites- fossil arthropods
(iii)Lung fishes – connecting link between fishes and amphibians
(iv)Peripatus – connecting link between annelids and arthropods .
(v) Woody mammoth – ice fossils
(vi)Gastropods – mould and cast fossil
(vii)Giant elk – amber fossil of asphalt
(viii)Dinosaur footprint – imprints
Question-3: 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.
Solution: Evolutionary stages of horse:
Eohippus – Mesohippus – Merychippus – Pliohippus – Equus.
(i)Increase in body size.
(ii)Elongation of neck.
(iii)Lengthening of limbs.
(iv)Enlargement of third digit.
(v)Increase in structural complexity of teeth for feeding on grass.