Can you think of reasons why more comple | Class 10 Science Chapter How do Organism Reproduce?, How do Organism Reproduce? NCERT Solutions

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.

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?

What is an homologous series? Explain with an example.

Why is variation beneficial to the species but not necessarily for the individual?

State the principle of an electric generator.

How are the alveoli designed to maximise the exchange of gases?

Draw the structure for the following compounds.                

       (i)    Ethanoic acid             (ii)   Bromopentane*
       (iii)  Butanone                   (iv)   Hexanal.

*Are structural isomers possible for bromopentane?

Give an example of a plant hormone that promotes growth.

Consider a circular loop of wire lying in the plane of the table. Let the current pass through the loop clockwise. Apply the right-hand rule to find out the direction of the magnetic field inside and outside the loop.

How is the small intestine designed to absorb digested food?

The kidneys in human beings are a part of the system for

   (a) nutrition.                  (c) excretion.
   (b) respiration.              (d) transportation.

Explain the formation of scum when hard water is treated with soap.

Metallic oxides of zinc, magnesium and copper were heated with the following metals.

In which cases will you find displacement reactions taking place?

What is the function of digestive enzymes?