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.

trachea, alveoli, lung capillaries, arteries

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

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