Biology Paper 1

[Rashu712]

hmm for the pea pod question wasnt the stigma on the extreme left side, which was A?

Yess I put A alssoooo ! Because the stigma is always present with the anthersss ! Or else how will pollination take placeee ?

yes so it is A

Pod was the one to the right, not the where it had the little things (stigmas), which I don't understand why

I choose the same as you

i am still not sure about the correct pea pod answer but i believe it was A because that lookes like a stigma and where the pollen grain would have entered

yes. I wrote A as well.

No, that is not possible at all. Remember that the stigma always stays on top of the fruit. The stigma originates over the Ovary.
I know this for sure because I grew pea plants and I have taken pictures of the first peas they produced. Therefore as a proof,
I'm adding a picture, where you can clearly see that the stigma is at the end of the pod. The anthers stay near the petals and the fruit grows
pushing the stigma further away from the anthers.

Notice the STIGMA at the end of the pod. That has to be where the pollen tube started growing (Pollination is the transfer of pollen from the anther to the stigma. The pollen sticks to the stigma and grows a pollen tube which finds its way to the micropyle, where the sperm fertilizes the ova and then develops into a fruit. Ovules become seeds and Ovary becomes to fruit.)
And you can see the ANTHERS growing out of the sepals.

The answer was D

Here's another image I found online on development of Sweetpeas. Here's a flower that shows the structures of its stigma, and anthers.
Notice that the stigma is in the centre and below it is a fleshy green fruit developing.

 

[Ramosk95]

@rashu
the anthers were on the left side and the photo to uploaded shows the same thing

 

[Rashu712]

@rashu
the anthers were on the left side and the photo to uploaded shows the same thing

I know that. We are arguing about the position of the STIGMA, not the anther. Pollen tube develops on the Stigma, not the anther.
Pollen is released from the anthers and are carried to the stigma. That is called pollination. To fertilize the Ova, the sperm from the pollen grain must be transferred to the ova in the ovules. Ovules lie below the stigma, and the stigma holds the pollen and creates suitable condition for the pollen on it to grow a pollen tube, reach the micropyle and transfer the sperm inside the ovule. That is fertilization. So the answer was D.
So, the pictures show that it's the stigma that pushes upwards as the fruit develops. Initially, the anthers and the stigma were about the same level at height, but as the fruit grows, the stigma stays at the end of the fruit and so moves away from its original position.
In the first picture, you can see the stigma at the extreme end of the pea pod.

 

[Chemguy]

One up Rashu!

Same answer