00:01
According to the logistic growth equation, a, the number of individuals added per unit time is greatest when n is close to zero.
00:09
B, the per capita growth rate increases as n approaches k.
00:14
C, the population growth is zero when n equals k.
00:20
D, the population grows exponentially if k is small.
00:24
Or e, the birth rate b approaches zero as n approaches k.
00:29
So first i'll draw what this actually looks like.
00:34
It gives us this logistic curve.
00:40
So it starts off slow, it becomes rapid, and then as it approaches the carrying capacity, which is k, it slows back down again.
00:47
So k is representing the carrying capacity, and r is representing the per capita growth rate.
01:01
And n is, of course, the population size.
01:04
Okay, so here we have dn over d t.
01:09
So this is t, this is n, and of course it's the gradient.
01:15
So it's highest when the graph is steepest.
01:20
Okay, so which of these is true? let's start with a.
01:22
The number of individuals added per unit time is greatest when n is close to zero.
01:27
Well, no, because that's down here where the gradient is still very low.
01:32
It's not that.
01:33
And that's because of the n, multiplying by.
01:37
The k minus n over k...