What are the changes seen in girls at th | 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?

What are the environmental consequences of using fossil fuels?
Suggest the steps to minimise the pollution caused by various sources of energy including non-conventional sources of energy.

How does the electronic configuration of an atom relate to its position in the Modern Periodic Table?

Match the terms of Column (A) with those of Column (B)

Samples of four metals A, B, C and D were taken and added to the following solution one by one. The results obtained have been tabulated as follows.

Why is the flow of signals in a synapse from axonal end of one neuron to dendritic end of another neuron but not the reverse?

Name two metals which are found in nature in the free state.

What causes movement of food inside the alimentary canal?

What are the different ways in which individuals with a particular trait may increase in a population?

What are the necessary conditions for autotrophic nutrition and what are its by-products?

Why do you think that there should be equitable distribution of resources? What forces would be working against an equitable distribution of our resources?