What does 'Red' indicate in the $IUCN$ Red List $(2004)$?

How many mass extinctions have occurred since the origin of life on Earth?

If the current rate of species extinction continues,what percentage of all species on Earth will become extinct within the next $100$ years (in $\%$)?

Which of the following species have recently become extinct?
$i)$ Dodo
$ii)$ Thylacine
$iii)$ Steller's sea cow
$iv)$ Quagga
$v)$ Javan

Loss of biodiversity in a region may lead to all of the following,except:

Identify the odd one out regarding recent extinctions.