Read the following statements (1 - 4) and identify how many of the given statements are correct?
Read the following statements (1 - 4) and identify how many of the given statements are correct?
The correct option is B 2
The tuataras (Sphenodon) are reptiles whose lineage goes back to 240 million years ago. They have very primitive heart. It is a connecting link between amphibians and reptiles. They have a very primitive heart and brain structure similar to that of the amphibians. Their general body shape is similar to that of the reptiles. Hence statement 2 is incorrect.
Figure : Sphenodon
Archaeopteryx is considered a transitional fossil between reptiles and modern birds. They had feathers on their body just like birds and their bones were not pneumatic. They had teeth and a weak sternum just like in reptiles. Pneumatic bones are hollow bones, which is the characteristic feature of the birds as its hollow nature doesn't limit their flight. Hence statement 3 is incorrect.
Figure : Archaeopteryx
Ginkgo biloba is considered a living fossil as it has remained unchanged for the past 51 million years. Similar trees were alive 170 million years ago. So statement 1 is correct.
Figure : Ginkgo biloba
Fossils are remains or traces of hard parts of ancient life-forms found in rocks preserved in the Earth’s crust. To find out the approximate age of the fossils, a carbon dating method is commonly used. This is based on the principle of radioactive decay.
All living organisms consume different amounts of isotopes of carbon (C-12 and C-14). C-12 is stable but C-14 is unstable and is radioactive.
When a plant or animal dies, the consumption of carbon stops but the decay of C-14 continues at a slower rate (it takes around 5730 years for 1g of radioactive C-14 to become 0.5g) until all of it has decayed. The disintegration of C-14 into C-12 remains constant. Hence, the quantity of C-14 relative to C-12 varies progressively with decay. Assuming that the decay rate is not affected by the prevailing environment, the relative age in which the organism existed can be determined by this method. The older the fossil is, the lesser the quantity of C-14 present in the sample. Hence statement 4 is correct.
Figure : Carbon dating method
The tuataras (Sphenodon) are reptiles whose lineage goes back to 240 million years ago. They have very primitive heart. It is a connecting link between amphibians and reptiles. They have a very primitive heart and brain structure similar to that of the amphibians. Their general body shape is similar to that of the reptiles. Hence statement 2 is incorrect.
Figure : Sphenodon
Archaeopteryx is considered a transitional fossil between reptiles and modern birds. They had feathers on their body just like birds and their bones were not pneumatic. They had teeth and a weak sternum just like in reptiles. Pneumatic bones are hollow bones, which is the characteristic feature of the birds as its hollow nature doesn't limit their flight. Hence statement 3 is incorrect.
Figure : Archaeopteryx
Ginkgo biloba is considered a living fossil as it has remained unchanged for the past 51 million years. Similar trees were alive 170 million years ago. So statement 1 is correct.
Figure : Ginkgo biloba
Fossils are remains or traces of hard parts of ancient life-forms found in rocks preserved in the Earth’s crust. To find out the approximate age of the fossils, a carbon dating method is commonly used. This is based on the principle of radioactive decay.
All living organisms consume different amounts of isotopes of carbon (C-12 and C-14). C-12 is stable but C-14 is unstable and is radioactive.
When a plant or animal dies, the consumption of carbon stops but the decay of C-14 continues at a slower rate (it takes around 5730 years for 1g of radioactive C-14 to become 0.5g) until all of it has decayed. The disintegration of C-14 into C-12 remains constant. Hence, the quantity of C-14 relative to C-12 varies progressively with decay. Assuming that the decay rate is not affected by the prevailing environment, the relative age in which the organism existed can be determined by this method. The older the fossil is, the lesser the quantity of C-14 present in the sample. Hence statement 4 is correct.
Figure : Carbon dating method
