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.
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.
Outline a project which aims to find the dominant coat colour in dogs.
Draw the structure for the following compounds.
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.
*Are structural isomers possible for bromopentane?
A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?
How is the sex of the child determined in human beings?
(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?
Calculate the number of electrons constituting one coulomb of charge.
What is an homologous series? Explain with an example.
Why is variation beneficial to the species but not necessarily for the individual?
A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
Outline a project which aims to find the dominant coat colour in dogs.
How is oxygen and carbon dioxide transported in human beings?
How are the lungs designed in human beings to maximise the area for exchange of gases?
Explain the underlying principle and working of an electric generator by drawing a labelled diagram. What is the function of brushes?
What is the role of the brain in reflex action?
Which of the following terms does not represent electrical power in a circuit?
(a) I2R (b) IR2 (c) VI (d) V2/R
You are given a hammer, a battery, a bulb, wires and a switch.
(a) How could you use them to distinguish between samples of metals and non-metals?
(b) Assess the usefulness of these tests in distinguishing between metals and non-metals.
Explain why the planets do not twinkle.
Explain different ways to induce current in a coil.
How do Mendel’s experiments show that traits are inherited independently?