What processes would you consider essential for maintaining life?
All the living organisms perform various processes during their life for their adaptations and the survival is known as life processes. There are very essential processes that are considered for maintaining their lives like reproduction (all organisms survives for the reproduction), digestion and absorption of food, respiration (for breathing and exchange of gases in the respiratory tract), body fluids and the circulatory system, excretion process, for locomotion and movement, growth processes, neural control and coordination process, chemical coordination and integration process.
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
How is the amount of urine produced regulated?
What are the different ways in which glucose is oxidised to provide energy in various organisms?
What criteria do we use to decide whether something is alive?
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 are the components of the transport system in highly organised plants?
What would be the consequences of a deficiency of haemoglobin in our bodies?
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?
Which of the following property of a proton can change while it moves freely in a magnetic field? (There may be more than one correct answer.)
(a) mass (b) speed
(c) velocity (d) momentum
Compounds such as alcohols and glucose also contain hydrogen but are not categorised as acids. Describe an Activity to prove it.
(a) What property do all elements in the same column of the Periodic Table as boron have in common?
(b) What property do all elements in the same column of the Periodic Table as fluorine have in common?
An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be
(a) calcium
(b) carbon
(c) silicon
(d) iron.
State Fleming’s left-hand rule.
When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.
Fe2O3 + 2Al → Al2O3 + 2Fe
The above reaction is an example of a
(a) combination reaction.
(b) double displacement reaction.
(c) decomposition reaction.
(d) displacement reaction.
What are the different methods of contraception?
The magnification produced by a plane mirror is +1. What does this mean?
Why is variation beneficial to the species but not necessarily for the individual?