Question

What are alleles?
(a) Alternate forms of a gene
(b) Homologous chromosome
(c) Pair of sex chromosome
(d) None of the above

Answer 1

Hint: The two or more versions of a gene that inherits from each one of the parents is known as an allele. It is used to describe the variation among genes which is also referred to as the variation among non-coding DNA sequences. Humans are the diploid organisms that contain two alleles at the genetic locus which are inherited by each one of the parents. Each pair of alleles represents the genotype of a specific gene.

Complete answer:
Alleles are the alternative forms of a gene for producing different effects. The homologous individual contains two alleles which are the same for that gene. Heterozygous individuals contain the elements which are different for that gene. Alleles are usually used to describe the variation among genes. Alleles can be dominant or recessive based on the phenotype. A heterozygous organism at a specific locus contains one dominant and one recessive allele. The organism carrying one dominant and one recessive allele expresses the dominant phenotype. Alleles do not influence the gene's phenotype.

Additional information:
Homologous chromosome: Homologous chromosome is the chromosome that contains one maternal and one paternal chromosome which pair during the fertilization inside the cell. They contain the same genes in the same loci. They help in arranging and aligning the chromosomes correctly before thor separation that occurs during meiosis. They are important for the processes of meiosis and mitosis as they allow the recombination and random segregation of genetic material from the father and mother into the new cells.
Pair of sex chromosome: Sex chromosome differs from the autosome in the form, behavior, and size. The sex chromosome is the sex of the individual which are produced during sexual reproduction. Human contains 23 pairs of chromosome in which 22 pairs are autosomes and one pair is the sex chromosome consisting of the X chromosome and a Y chromosome. The x chromosome is present in the females and the chromosomes are present in the males. Females consist of XX chromosomes while the males have XY chromosomes. The individual during sexual reproduction must receive an X chromosome and a Y chromosome to produce a male individual. To produce a female individual, the individual during sexual reproduction must receive an X chromosome from the female and the X chromosome from the male. This occurs during the fusion of gametes.
So, the correct answer is '(a) Alternate form of a gene'.

Note: AlAn alleles also are known as allelomorphs. The word genes were coined in the 20th century. Humans are identical on the genetic level up to $99\mathrm{\%}$. On the evolution of species, the genes can disappear or break. The voluminous eyelashes of Elizabeth Taylor are the result of genetic mutation. Elephants contain a zombie gene that helps to protect from cancer octopuses have an ability by which they can edit their genes.