What causes movement of food inside the alimentary canal?
Alimentary canal is a long tube with muscular walls, glandular epithelial lining and contains four main concentric coats (visceral peritoneum, muscular coat, submucosa and mucosa). Alimentary canal contains muscular layers through which rhythmic contraction, expansion and relaxation occurs through which food enters the alimentary canal and causes the peristalsis movement. Hence peristalsis is the process which causes the movement of food inside the alimentary canal.
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?
Why does the cord of an electric heater not glow while the heating element does?
What is an homologous series? Explain with an example.
How is the equal genetic contribution of male and female parents ensured in the progeny?
Butanone is a four-carbon compound with the functional group
(a) carboxylic acid.
(b) aldehyde.
(c) ketone.
(d) alcohol.
What would be the advantages of exploiting resources with short-term aims?
While diluting an acid, why is it recommended that the acid should be added to water and not water to the acid?
The position of three elements A, B and C in the Periodic Table are shown below –
Group 16 Group 17
- -
- A
- -
B C
(a) State whether A is a metal or non-metal.
(b) State whether C is more reactive or less reactive than A.
(c) Will C be larger or smaller in size than B?
(d) Which type of ion, cation or anion, will be formed by element A?
What is the need for a system of control and coordination in an organism?
Oil and fat containing food items are flushed with nitrogen. Why?
Compare and contrast the arrangement of elements in Mendeléev’s Periodic Table and the Modern Periodic Table.