Mendelian Genetics Quiz

Mendelian Genetics

• Gregor Mendel's experiments with pea plants established the fundamental principles of inheritance.
• Mendel discovered that traits are inherited as discrete units, now known as genes.
• He observed dominant and recessive traits, where one trait masks the expression of another.
• Mendel's laws of segregation and independent assortment describe how alleles separate during gamete formation and how different gene pairs segregate independently.
• The law of segregation states that each individual receives one allele for each gene from each parent.
• The law of independent assortment states that the inheritance of one gene does not affect the inheritance of another gene.
• Mendel's work provided the basis for understanding how traits are passed from one generation to the next.

Concepts of Genes and Alleles

• Genes are segments of DNA that code for specific traits or characteristics.
• Alleles are different forms of a gene.
• Alleles can be dominant, recessive, or codominant.
• Dominant alleles mask the expression of recessive alleles.
• Recessive alleles are only expressed when an individual carries two copies of the recessive allele.
• Codominant alleles are both expressed in heterozygous individuals.
• The combination of alleles an individual inherits determines the phenotype (observable traits).
• Genotype refers to the genetic makeup of an individual, while phenotype corresponds to the observable traits.

Beyond Mendelian Genetics

• Incomplete dominance occurs when one allele is not completely dominant over another, resulting in an intermediate phenotype.
• Multiple alleles describe genes with more than two possible alleles. Blood type is determined by a classic example.
• Polygenic inheritance involves multiple genes contributing to a single trait, such as height or skin color.
• Epistasis describes the interaction between genes where one gene affects the expression of another.
• Pleiotropy is a single gene affecting multiple phenotypic traits.
• Environmental factors can influence the expression of genetic traits.
• Linkage refers to genes located close together on a chromosome tending to be inherited together.
• Sex-linked traits are determined by genes located on sex chromosomes, often exhibiting different expression patterns in males and females.

DNA Structure and Function

• DNA (deoxyribonucleic acid) is a double helix composed of nucleotides.
• Each nucleotide consists of a sugar molecule, a phosphate group, and a nitrogenous base (adenine, guanine, cytosine, or thymine).
• DNA stores genetic information.
• The sequence of nucleotides determines the genetic code.
• DNA replication is a semiconservative process that ensures accurate duplication of genetic information.
• DNA replication involves unwinding the double helix, separating the strands, and synthesizing complementary strands.

Protein Synthesis

• Central dogma: DNA ->RNA ->protein
• Proteins are essential components in many biological processes.
• Protein synthesis involves two main stages: transcription and translation.
• Transcription converts the DNA code into mRNA.
• Translation uses mRNA to synthesize proteins.
• Gene expression is the process by which the information in a gene is used to synthesize a functional gene product.
• Gene regulation mechanisms control the expression of genes in response to cellular signals or needs.