Explain the three pathways of breakdown in living organisms.
Glucose is broken down into 3- carbon molecules known as pyruvate and three pathways (in yeast, in muscle cells and in mitochondria) of breakdown in living organisms as shown in figure:-
In yeast:- Glucose first breaks down into pyruvate and pyruvate then converted into ethyl alcohol (ethanol) and carbon dioxide in the absence of oxygen known as anaerobic respiration.
In muscle cells:- In this pyruvate breaks down into lactic acid. When we do the heavy workout or running then our body needs more oxygen that time but it is not possible for our muscle cells to respire aerobically. So due to lack of oxygen anaerobic respiration takes place in muscle cells.
In mitochondria:- Aerobic respiration metabolism occurs in mitochondria and cytoplasm. In this, pyruvate breaks down into carbon dioxide and water. Most of the organisms respire aerobically.
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
How is the amount of urine produced regulated?
What criteria do we use to decide whether something is alive?
What are the different ways in which glucose is oxidised to provide energy in various organisms?
The breakdown of pyruvate to give carbon dioxide, water and energy takes place in
(a) cytoplasm. (c) chloroplast.
(b) mitochondria. (d) nucleus.
What are the differences between autotrophic nutrition and heterotrophic nutrition?
What are outside raw materials used for by an organism?
What would be the consequences of a deficiency of haemoglobin in our bodies?
What are the components of the transport system in highly organised plants?
What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?
Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
What is a good source of energy?
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
What changes can you make in your habits to become more environment-friendly?
What is the difference between a reflex action and walking?
What is the importance of DNA copying in reproduction?
If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?
Why should a magnesium ribbon be cleared before burning in air?
Define the principal focus of a concave mirror.
You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?
If you could use any source of energy for heating your food, which one would you use and why?
Give two important uses of washing soda and baking soda.
Only variations that confer an advantage to an individual organism will survive in a population. Do you agree with this statement? Why or why not?
Write the balanced chemical equations for the following reactions.
(a) Calcium hydroxide + Carbon dioxide → Calcium carbonate + Water
(b) Zinc + Silver nitrate → Zinc nitrate + Silver
(c) Aluminium + Copper chloride → Aluminium chloride + Copper
(d) Barium chloride + Potassium sulphate → Barium sulphate + Potassium chloride
What are plant hormones?
What are the two properties of carbon which lead to the huge number of carbon compounds we see around us?
Butanone is a four-carbon compound with the functional group
(a) carboxylic acid.
(b) aldehyde.
(c) ketone.
(d) alcohol.
What precaution should be taken to avoid the overloading of domestic electric circuits?
The essential difference between an AC generator and a DC generator is that
(a) AC generator has an electromagnet while a DC generator has permanent magnet.
(b) DC generator will generate a higher voltage.
(c) AC generator will generate a higher voltage.
(d) AC generator has slip rings while the DC generator has a commutator.
Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).