Heredity and Genetics Notes

DNA

Deoxyribonucleic Acid, the molecule carrying genetic instructions.

Double Helix

The structure formed by two chains of nucleotides in DNA.

Base Pairing Rules

Rules that dictate how nitrogenous bases pair (A = T, C = G).

Purines

Nitrogenous bases that include Adenine (A) and Guanine (G).

Pyrimidines

Nitrogenous bases that include Cytosine (C) and Thymine (T).

Transcription

The process of converting DNA into mRNA to code for proteins.

Exons

Expressed sequences in mRNA that code for proteins.

Introns

Non-coding sequences in mRNA that are removed before translation.

Central Dogma of Molecular Biology

The process of DNA being transcribed to RNA and then translated to protein.

Genome

The entire DNA set of an organism.

Karyotype

The chromosomal layout of an organism.

Mitosis

The process of somatic cell division producing two identical diploid cells.

Meiosis

The process that produces four genetically unique haploid cells, promoting genetic diversity.

Nondisjunction

The failure of chromosomes to separate properly during meiosis, leading to genetic disorders.

Natural Selection

The process by which genetic variation leads to evolutionary advantages.

Heredity

The transmission of genetic traits from parents to offspring.

Gregor Mendel

The father of genetics known for his work on pea plants and the laws of inheritance.

Dominant Trait

A trait expressed even if only one dominant allele is present.

Recessive Trait

A trait expressed only if both alleles are recessive.

Punnett Square

A tool to predict the genetic outcomes of offspring.

Complete Dominance

A form of inheritance in which one allele completely masks the other.

Incomplete Dominance

A form of inheritance where neither allele is fully dominant, resulting in a blended phenotype.

Co-Dominance

A form of inheritance where both alleles are expressed simultaneously.

Mendelian Traits

Traits controlled by a single gene with little environmental influence.

Non-Mendelian Traits

Traits influenced by multiple genes and environmental factors.

X-Linked Recessive

A condition more common in males where the trait is carried on the X chromosome.

PTC Tasting

A trait studied by Mendel, where some individuals can taste bitterness due to a single gene.

Epigenetics

The study of how environmental factors influence gene expression without changing DNA sequences.

Genetic Variation

Diversity in gene frequencies within a population, crucial for adaptation and survival.