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Biology; Chemistry; Physics: Post your doubts here!

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mostly students wrote self pollination as an answer to this question so i am confused can insect pollination be an answer to this question because it was a different question came in our recent june 2014 exams. please reply soon.

Self-pollination

is a form of pollination that can occur when a flower has both stamen and a carpel (pistil) in which the cultivar or species is self fertile and the stamens and the sticky stigma of the carpel contact each other in order to accomplish pollination. The term is inaccurately used in many cases where an outside pollinator is actually required; such plants are merely self-fertile, or self pollinizing.

Entomophily (insect pollination) is a form of pollination whereby pollen or spores are distributed by insects. Several insects are reported to be responsible for the pollination (potential or effective) of many plant species, particularly bees, Lepidoptera (e.g., butterflies and moths), wasps, flies, ants and beetles. Some plant species co-evolved with a particular pollinator, such as many orchids species. On the other hand, there are plant species which are generalists, being visited and/or pollinated by several insect groups.[1] Entomophilous species frequently evolve mechanisms to make themselves more appealing to insects, e.g., brightly colored or scented flowers, nectar, or appealing shapes and patterns. Pollen grains of entomophilous plants are generally larger than the fine pollens of anemophilous (wind-pollinated) plants. They usually are of more nutritional value to insects, which may use them for food and inadvertently spread them to other flowers.
So these both are just like same>......................... (not sure)
Plx like this
 
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no it cannot be a wind pollinated plant since the anthers do not dangle outside the flower so it can either be insect pollination or self pollination since the question says that which pollination is likely to take place before a flower opens. plz give me a clear answer
 
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no it cannot be a wind pollinated plant since the anthers do not dangle outside the flower so it can either be insect pollination or self pollination since the question says that which pollination is likely to take place before a flower opens. plz give me a clear answer
which paper can you give me the code and name of the subject and year and season
 
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but it can be insect pollination as well.
Alright.It was self pollination.It said BEFORE it opens,so obviously it will be self pollinated as no external agents could be involved.About the earlier q i answered to whether it would be insect or not.It was a wheat plant and they are wind pollinated but in this case the answer was self as it was b4 it was opened.
 
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hi guys, I am planning to give O Level Biology in Oct/Nov 2014. I haven't studied Biology in my past years bcz I wasnt serious about it. I have given six subjects in this May/june 2014*phys, chem, maths, add.maths, computer, english). I actually want to become a psychiatrist so i knw i must complete my med college so therefore biology is necesary. I'm thinking to give O level bio then a level bio. \plz guide me people. Will it be okay 4 me to give bio ppr in 4 mnths and to study 4rm the scratch??
 
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Hi guys, i am planning to give o level biology in this oct/nov session 2014. I'm planning to go in medical therefore biology is the main requirement for that. Unfortunately i didnt study it in the past three years of my schooling bcz at that time i hadnt made up my mind. I have given six papers in this may/june 2014 session. (phys, chem, maths, add.maths, computer, eng). I dont really want to become an engineer of some sort. Neither I have got interest in commerce field. So, is it okay 4 me to study O level Bio in these four months from the scratch?? So that I can take A Level Biology in future???
 
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pl

plx give me the ans
1.Using right hand grip rule, find the direction of magnetic fields
2.As they (wires)are in opposite direction they repel each other,,,,,,,,,,Hence C is correct as it shows both of these conditions
fulfilled. Note in D there is attraction.
 
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Hi there,
There is a question in physics from 5054_s03_qp_1
The answer is B, why would the frequency be reduced?
upload_2014-7-8_7-56-36.png
 
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Hi there,
There is a question in physics from 5054_s03_qp_1
The answer is B, why would the frequency be reduced?
View attachment 46024
Since the resistor and the capacitor are in series, voltage will be divided across them.
Increasing the resistance of R increases the voltage across it. Thus less voltage is across the capacitor. Since there is less initial voltage, it will take a longer period of time for the voltage across the capacitor to reach 110 V. Thus in a unit time, the bulb will light up and go out less frequently

Imagine this as 2 cars having the same acceleration. Both cars intend to reach 100 m/s
In the first car A, its initial velocity is 50 m/s. It will take a short period of time to reach 100 m/s
The second car B, has an initial velocity of 20 m/2. So it will take a longer period of time for it to reach 100 m/s
 
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What is the process of Crystallisation ? How is it used as a purification technique ? I don't understand this topic :/ Please help :)
 
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