Origin and Evolution of Life — BIOLOGY STD 12 Science — Question

A-1 The sum total of genes of all individuals of interbreeding population or Mendelian population is called gene pool.
A-2 The proportion of an allele in the gene pool as compared with other alleles at the same locus is termed as gene frequency.
A-3 Organic evolution can be defined as slow, gradual, continuous and irreversible changes through which the present-day complex forms of the life developed (or evolved) from their simple pre-existing forms.
A-4 All individuals of the same species form a group which is called a population.
A-5 Formation of new species from the pre-existing single group of organisms is called speciation.