Physics, Chemistry and Biology: Post your doubts here!

[sumangupta]

Can some one explain this part of the syllabus for me:
Explain why there is an increased efficiency in supplying green plants as human food and that there is a relative inefficiency, in terms of energy loss, in feeding crop plants to animals

In my notes the explanation is as follows"
If plants are fed to animals, and the animals are then eaten, it is less efficient than directly eating the plants, because the animal hasn’t used up some of the plants energy, allowing plants to feed more people.

with an increase in each trophic level, about 10% of energy is lost by the animals due to, respiration, excretion, and other metabolic processes.
Thus it is more efficient to consume on green plants rather than animal food for, only 10% of energy provided by plants would be attained through thd animals.

hope this helps...

 

[sumangupta]

When there is a cut, fibrinogen is converted to fibrin which forms a net like trap to trap all the red blood cells to prevent the blood from flowing, it dries to form a scab.

thanks...
i guess this was too simplified...!!

 

[sumangupta]

Err.. U took it? Really?

oops...i'm sorry...i understood ur question wrong...!!!

 

[suhaib05]

I need help in understanding the relationship between sickle cell anaemia/allele and malaria: how come areas where malaria is common are also the areas where sickle cell anaemia/allele is common? Doesn't a heterozygous individual have a resistance to malaria, which means that malaria should NOT be common where the sickle cell allele is common?

If it helps, check Q5(d) in this paper: http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Biology (0610)/0610_s09_qp_3.pdf.

 

[Yousif Mukkhtar]

Guys, what do we need to know about Deamination? Is the definition from the syllabus enough?

 

[sma786]

Can't see the question.

ohh y

 

[always-smile :)]

Guys, what do we need to know about Deamination? Is the definition from the syllabus enough?

u shuold knw which part is taken for energy and which part is left as wast sub

 

[Yousif Mukkhtar]

u shuold knw which part is taken for energy and which part is left as wast sub

So the nitrogen containing part is used for making urea and the remaining is used for energy production.

 

[ali khan saaed]

ooooooooooooooooooooooooooo

 

[always-smile :)]

So the nitrogen containing part is used for making urea and the remaining is used for energy production.

yup
hope i helped

 

[Yousif Mukkhtar]

yup
hope i helped

Yeah, you did. Thanks.

 

[always-smile :)]

Yeah, you did. Thanks.

ur welcome any time

 

[stayawayfromhere]

what do we have to know about negative feedback and hormones in food production ? and what do we have to know about behavior ? only taxis right ? or also the definition of it ? please reply ASAP

 

[always-smile :)]

people is there anything called capillary tube in bio

 

[stayawayfromhere]

people is there anything called capillary tube in bio

yes , the xylem vessel is a narrow tube therefore it causes water ascent by capillarity action , thus it acts as a capillary tube

 

[always-smile :)]

yes , the xylem vessel is a narrow tube therefore it causes water ascent by capillarity action , thus it acts as a capillary tube

so that's it ....oh thank u a million i was going crazy don't knw wat it is but it's simple

 

[stayawayfromhere]

so that's it ....oh thank u a million i was going crazy don't knw wat it is but it's simple

Glad i helped may God grant all of your wishes , you're very welcome

 

[sumangupta]

I need help in understanding the relationship between sickle cell anaemia/allele and malaria: how come areas where malaria is common are also the areas where sickle cell anaemia/allele is common? Doesn't a heterozygous individual have a resistance to malaria, which means that malaria should NOT be common where the sickle cell allele is common?

If it helps, check Q5(d) in this paper: http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Biology (0610)/0610_s09_qp_3.pdf.

heterozygous individuals do not suffer from sickle cell anaemia, thus they are less resistive to the disease for, their RBCs are not sickle shaped

 

[sumangupta]

Guys, what do we need to know about Deamination? Is the definition from the syllabus enough?

-Takes place in anaerobic conditions
-Convertes Nitrates into Nitrogen gas (....i guess this much is enough)

 

[stayawayfromhere]

Guys, what do we need to know about Deamination? Is the definition from the syllabus enough?

deamination : the removal of nitrogen containing compound in amino acids as urea then follows the production of energy from the remaining .
it's broken down into organic acid : stored as fats and carbohydrates and amine group : -changes to ammonia by certain reactions then ammonia combines with CO2 and becomes urea which is excreted with urine