00:01
So this question gives us four different statements about mammals, and it asks us to identify which one of these is true.
00:07
So my favorite approach to these kinds of questions is to go through each statement and find exceptions that might prove that statement wrong.
00:16
And then we can go back through and find out which one is the most correct after ruling out the ones that are incorrect.
00:23
So we'll start with the first one, and the first one states that in all mammals, offspring completely develop in the female.
00:30
So i'll think of some common mammals such as dogs and cats.
00:38
So dogs and cats both give live birth, so their offspring does completely develop in the female.
00:46
So these ones check out.
00:49
But what if we consider the platypus? the famous platypus actually lays eggs, so that means that the offspring must continue developing in the egg that is laid outside of the female.
01:02
So this one does not fit.
01:06
Therefore, this statement not really true, so it's probably not the correct answer.
01:12
So we'll go on to the second statement.
01:15
The second statement says that all mammals have mammary glands and hair.
01:19
Well, this seems pretty logical because as the same implies, mammary glands is what mammals are named after.
01:26
Very similar.
01:30
But what about the hair part? so let's think of some more examples.
01:33
Can we think of any mammals that don't have hair? well, some animals that initially come to mind, for me, are dolphins and whales and the naked mole rat, which as its name implies, has no hair.
01:50
Well, when we take a closer look, all of these animals actually do have hair.
01:56
It's just not easy to observe with the naked eye or at first glance...