QCM : Fundamentals of Genetic Inheritance — 7 questions

Explication

Genotype refers to the specific alleles inherited from the parents, which make up an organism's genetic makeup. It is distinct from phenotype, which describes the observable traits. The other options describe phenotypic traits, gene location, or gene function, which are not defining features of genotype.

Explication

Allelic variation, which involves different versions of the same gene, is the primary cause of differences in inherited traits among individuals, leading to trait diversity and inheritance patterns.

Explication

Constructing a Punnett square using the parental genotypes (e.g., Aa x Aa) applies Mendel's Law of Segregation and allows prediction of offspring genotypes and phenotypes. This method is the practical application of Mendel's laws for analyzing inheritance patterns.

Explication

Homologous chromosomes pair up during meiosis and segregate into different gametes, ensuring each gamete receives one chromosome from each pair. This process is crucial for maintaining the diploid number in offspring and generating genetic diversity. The options about carrying different genes are true but describe their composition rather than their primary function during meiosis; separating sister chromatids occurs in mitosis and meiosis II, not specifically the role of homologous pairs. DNA replication is a distinct process preceding meiosis but not the primary function of homologous chromosomes themselves.

Explication

Mendel's Law of Segregation states that allele pairs separate during gamete formation, so each gamete carries only one allele for each gene. The other options are incorrect: the first describes a false idea that alleles do not separate; the third describes independent assortment, not segregation; the fourth describes dominance, which is related but not what the law states.

Explication

The P generation consists of the original parent organisms used in a genetic cross, and the F1 generation is the first set of offspring resulting from crossing the P generation. This fundamental distinction is key to Mendelian experiments, where P is the starting point and F1 is the first filial generation.

Explication

Gregor Mendel is credited with proposing the laws of inheritance, such as the Law of Segregation and the Law of Independent Assortment, which explain how chromosomes carry and transmit genetic information. These laws form the basis for understanding chromosome composition and behavior during inheritance. Darwin did not formulate these laws; Watson and Crick discovered the structure of DNA, and Franklin contributed to X-ray crystallography of DNA, but neither proposed inheritance laws.