What are the components of the transport system in human beings? What are the functions of these components?
The main components of the transport system in human beings are blood or lymph, circulatory system and blood vessels. There are some main materials that needs to transport in our body like water, minerals, nutrients, gases, hormones, waste material and cells which protects our body for the diseases by the various systems.
Blood:- it is a mobile fluid, sticky and is basic (pH 7.4) and is of two types- oxygenated and deoxygenated. Blood is composed of four components- plasma, Red blood corpuscles, White blood corpuscles and Platelets. Plasma helps in the transportation of the food like glucose, certain amino acids, triglycerides, vitamins, minerals through the plasma from alimentary canal to the tissues for the growth and maintenance; helps in transportation of oxygen from lungs to the tissues for the breakdown of the food; transportation of carbon dioxide from the tissues to the lungs for the elimination from the body; transportation of hormones, wastes materials, metabolic processes products and also helps in the regulation of the hydrogen ion concentration, body temperature etc. Red blood cells help in the transport of oxygen and carbon dioxide by forming oxyhaemoglobin and carbaminohemoglobin respectively. White blood cells plays important role in the body defence against the microorganisms. And, platelets plays vital role in the blood clotting.
Circulatory system or heart:- function of the heart is to pump the oxygenated blood and the deoxygenated blood and some body fluids. Oxygenated blood is pumped throughout the body and takes deoxygenated blood from the various parts of the body to the lungs for the purification of blood from the impure blood.
Blood vessels:- blood vessels are elastic, muscular tubes and consists of Arteries and Veins. Arteries carry the blood from the heart to the various parts of the body through the blood vessels and the veins carry the blood from the various parts of the body to the heart through the blood vessels. And, they both arteries and veins joined together by capillaries. This process is completed by the blood vascular system and the lymphatic system.
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.
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?
Why is variation beneficial to the species but not necessarily for the individual?
Find the power of a concave lens of focal length 2 m.
(a) Lithium, sodium, potassium are all metals that react with water to liberate hydrogen gas. Is there any similarity in the atoms of these elements?
(b) Helium is an unreactive gas and neon is a gas of extremely low reactivity. What, if anything, do their atoms have in common?
Give reasons
(a) Platinum, gold and silver are used to make jewellery.
(b) Sodium, potassium and lithium are stored under oil.
(c) Aluminium is a highly reactive metal, yet it is used to make utensils for cooking.
(d) Carbonate and sulphide ores are usually converted into oxides during the process of extraction.
Give an example of a double displacement reaction other than the one given in activity 1.10.
Give the names of two energy sources that you would consider to be exhaustible. Give reasons for your choices.
Judge the equivalent resistance when the following are connected in parallel – (a) 1 Ω and 106 Ω, (b) 1 Ω and 103 Ω, and 106 Ω.
Suggest some approaches towards the conservation of forests.
An object of size 7.0 cm is placed at 27 cm in front of a concave mirror of focal length 18 cm. At what distance from the mirror should a screen be placed, so that a sharp focussed image can be obtained? Find the size and the nature of the image.
10 mL of a solution of NaOH is found to be completely neutralised by 8 mL of a given solution of HCl. If we take 20 mL of the same solution of NaOH, the amount HCl solution (the same solution as before) required to neutralise it will be
(a) 4 mL (b) 8 mL (c) 12 mL (d) 16 mL
How do we detect the smell of an agarbatti (incense stick)?