Assertion A is correct. Vertebrates possess a notochord during embryonic development, which is later replaced by a vertebral column.
Reason R is incorrect. All vertebrates are chordates, but not all chordates are vertebrates (e.g., tunicates, cephalochordates). The presence of a notochord at some stage in development is a defining characteristic of chordates. The relationship between chordates and vertebrates is not accurately described in R.
List - I | List – II | ||
A. | Lemur | i. | Flying phalanger |
B. | Bobcat | ii. | Numbat |
C. | Anteater | iii. | Spotted cuscus |
D. | Flying squirrels | iv. | Tasmanian tiger cat |
A bob of heavy mass \(m\) is suspended by a light string of length \(l\). The bob is given a horizontal velocity \(v_0\) as shown in figure. If the string gets slack at some point P making an angle \( \theta \) from the horizontal, the ratio of the speed \(v\) of the bob at point P to its initial speed \(v_0\) is :