Q&A - P5 Science

[StudyRoom]

Jamesbond:

PSLEguru:

[quote=\"Jamesbond\"]http://i44.tinypic.com/ra9kl5.jpg\">

Pl help me answer.

Seems to be a little ambiguous. I suppose the question wants you to recognise that duckweed floats on water.
(1) littler won't obscure sunlight from the duckweed
(2) similarly, oil spill won't obscure sunlight. Although the water will still be polluted...
(3) chemicals will be an issue because the plants may get poisoned.
(4) soil erosion will cloudy the water, but since the plants float, it may be less affected.
So (3) seems to be the best answer.

Although (1), (2) and (4) may also cause the duckweed to die.

Answer given is 3. Was wondering how chemicals came in to pond? If it was a lake or river, then agreed. Can u pl tell me what is the source of chemicals here to clear my doubt? TIA.[/quote]You don't have to wonder how chemicals came to the pond. You only know something is causing the plants to die.

Some one could have poured chemicals in.

Maybe someone decided to do his laundry there and poured a whole bottle of bleach in.

It doesn't matter.

[Jamesbond]

Oh....I never thought such things could happen in a pond.... :scared: Shall learn now.....

[Jamesbond]

http://i44.tinypic.com/2yngfax.jpg\">

For the question,
1) The plant is dying.
2) The stem below the cut ring swells a little.
Is my answer correct or not?

[StudyRoom]

Jamesbond:

http://i44.tinypic.com/2yngfax.jpg\">

For the question,
1) The plant is dying.
2) The stem below the cut ring swells a little.
Is my answer correct or not?

I think:
1) is correct
2) should be there is no swelling around the cut ring. (if anything, the swelling should be above, not below, the cut ring.)

The swelling in Plant X is due to food being produced in the leaves - this gets transported down the stem. Since the food carrying tubes are cut away, the stem swells above the cut area.

However, since in Plant Y, the cut area is above the water, the plant is not able to transport water up to the leaves, so the leaves are unable to produce food, and therefore there is no swelling.

[Jamesbond]

PSLEguru:

Jamesbond:

http://i44.tinypic.com/2yngfax.jpg\">

For the question,
1) The plant is dying.
2) The stem below the cut ring swells a little.
Is my answer correct or not?

I think:
1) is correct
2) should be there is no swelling around the cut ring. (if anything, the swelling should be above, not below, the cut ring.)

The swelling in Plant X is due to food being produced in the leaves - this gets transported down the stem. Since the food carrying tubes are cut away, the stem swells above the cut area.

However, since in Plant Y, the cut area is above the water, the plant is not able to transport water up to the leaves, so the leaves are unable to produce food, and therefore there is no swelling.

My doubt is since the water tubes are cut, the absorbed water cannot be transported up and it causes to swell below the cut.

[StudyRoom]

Jamesbond:

My doubt is since the water tubes are cut, the absorbed water cannot be transported up and it causes to swell below the cut.

Good inference - however the water doesn't cause swelling.

[Jamesbond]

PSLEguru:

Jamesbond:

My doubt is since the water tubes are cut, the absorbed water cannot be transported up and it causes to swell below the cut.

Good inference - however the water doesn't cause swelling.

Thx.

[Jamesbond]

http://i41.tinypic.com/207w220.jpg\">

In answering the property for such question, is it better we say, solids have def vol and occupy space. Or jus say any one of the property.

[StudyRoom]

Jamesbond:

http://i41.tinypic.com/207w220.jpg\">

In answering the property for such question, is it better we say, solids have def vol and occupy space. Or jus say any one of the property.

To be safe, I'd say both
Solids have def vol and occupy space, AND
liquids have def vol and takes the shape of its container, so it's able to flow around the smaller plasticine and so the total volume remains at 200ml.

[Jamesbond]

PSLEguru:

Jamesbond:

http://i41.tinypic.com/207w220.jpg\">

In answering the property for such question, is it better we say, solids have def vol and occupy space. Or jus say any one of the property.

To be safe, I'd say both
Solids have def vol and occupy space, AND
liquids have def vol and takes the shape of its container, so it's able to flow around the smaller plasticine and so the total volume remains at 200ml.

Thanks a lot.