Sunday, July 20, 2008

Life processes

Students First Terminal Exams is approaching. Let us revise the text book questions of chapter Life processes.
Q1. Why is diffusion insufficient to meet the oxygen requirements of multicultural organisms like humans?
Ans . In unicellular organisms the entire surface of the organism is in contact with the environment. But in multicultural organisms all the cell may not be in direct contact with the surrounding environment. So diffusion is insufficient to meet the oxygen requirements of all the cells.
Q2. What criteria do we use to decide whether something is alive?
Ans. Living organisms must do breathing, movements, growth and development. Living creatures must keep repairing and maintaining their structures. They also produce their young ones.
Q3. What are outside raw materials used for by organisms?
Ans. Carbon based molecules like carbohydrates, proteins. and fats. Other molecules such as lipids, Vitamins and minerals are also essential.
Q4. What processes would you consider essential for maintaining life?
Ans. Digestion, Respiration Transportation and Excretion are essential for maintaining life.

Nutrition
Q1. What are the differences between autotrophic and heterotrophic nutrition?
Ans. Refer modes of nutrition given in the blog
Q2. Where do plants get each of the raw materials required for photosynthesis?
Ans
1. CO2 –from atmosphere through stomata
2. H2O – From soil through roots.
3. Other raw materials like nitrogen, phosphorus, iron and magnesium are taken up from the soil. Nitrogen is the most important material which is absorbed in the form of NO3-, NO2-.or is taken in the form of organic compounds which are prepared by bacteria from atmospheric nitrogen is used to form protein.




7 comments:

pooja said...

thanx for the help mam........

Neha said...

Thanks mam for the exercise

Rupal said...

thanx mam but mam where we can see our holidays homework

yukti said...

mam i'm a student of class X-I
in our H.H.W. there is diagram of sectional view of hear
i think its a mistake
it should be either heart or ear
can you plz help me......
thank you!!

bobby said...

i really feel good to visit this site....
The explanation is quite impressive....
i congratulate.........

bobby said...
This comment has been removed by the author.
jaigurudev said...

Thankzz. . . .