Which term names two different forms of a single gene? a. traits b. alleles c. factors d. chromosomes

B. Alleles.

A variant form of any given gene is an allele. One of the two alternative forms of any particular gene which is present at the same locus of the chromosome is an allele.

Different forms of an allele determine the phenotypic traits. Most of the multicellular organisms are diploid having two sets of chromosomes, each inherited from one parent. If both the alleles of any gene are same on the particular position of chromosome then it is termed as homozygous and if the alleles of the gene are different, it is called heterozygous.

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.