Which of the following is an example of a postzygotic...

Which of the following is an example of a postzygotic barrier? Two species have reproductive organs that are physically incompatible. Different courtship displays prevent two species from interbreeding. Two species produce zygotes that fail to develop normally and die prior to birth. Breeding occurs at different times of the day for two species in the same area.

Transcript

00:01 Hi there.

00:02 This question is about post -zygotic barriers.

00:08 This refers to barriers after the zygote is formed.

00:13 All right.

00:19 So these are barriers to a species going on and if there's a cross going on and having more of those hybrid individuals.

00:27 So we're looking for these barriers that prevent those hybrid individuals from populating.

00:33 And these are things that happen after fertilization.

00:37 So after the zygote is formed.

00:39 So these are things that are going to prevent viable fertile offspring and specifically adults because we need to we're talking about them getting to reproductive age.

01:02 So a post -cygotic barrier or something that prevents viable fertile adults.

01:06 So let's look at these options that we have here.

01:09 The first one talks about two beetle species that live in different trees, different tree species.

01:16 So they're never going to probably cross each other's path.

01:20 They're never going to come in contact, so they are never going to mate.

01:24 So this would be a pre -zygotic barrier.

01:27 So the first one is no, because that's a pre -zigotic.

01:31 The second one, we have two hummingbird species, and they have different breeding seasons.

01:37 So they will never mate, but that's because they made it different times.

01:42 So that's also a pre -zigotic barrier.

01:45 The third one, we have these oak tree species in her breeding, and they're producing offspring, but their offspring have a particularly high mortality rate, meaning the offspring, they don't grow well, they don't reach a high, they don't reach maturity because they have a high mortality rate.

02:05 So this is something that is preventing viable adults...

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