The development of an oppposing thumb made it difficult for the early primates to grab things.

Q. Why it is difficult to develop vaccines for some diseases?

Q. For Fleming's left-hand rule, write down the three things that are 90° to each other, and next to each one write down the finger or thumb that represents it.

Q. State whether the following statements are true or false
The evolutionary history of primates dates back to early Palaeozoic era, about 300 million years ago.

Q. Early primates resembled

Q. Which among the following has an opposable thumb?