Genetics Reviewer Flashcards

Flashcards covering key vocabulary from a genetics lecture, including genes, chromosomes, alleles, inheritance patterns, mutations, Mendelian heredity, DNA structure and function, the central dogma of molecular biology, and different types of mutations.

Genes

Segments of DNA that contain the instructions for building proteins, which carry out essential functions within cells and determine an organism’s traits.

Chromosomes

Structures into which DNA is organized, passed down from parents to offspring, containing the complete genetic information required for development, growth, and reproduction. Humans have 46 chromosomes arranged in 23 pairs.

Alleles

Different forms of a gene located at a specific location on a chromosome; their combination influences an organism’s phenotype. Can be dominant or recessive.

Inheritance Patterns

Describe how traits are passed from parents to offspring, including Mendelian inheritance and more complex patterns like incomplete dominance, codominance, and polygenic inheritance.

Mutations

Changes in the DNA sequence that can lead to genetic variation, serving as a key source of genetic diversity and fuel for natural selection.

Mendelian Heredity

Principles of inheritance described by Gregor Mendel, providing the foundation for understanding how traits are inherited, including the Law of Segregation, Law of Independent Assortment, and Dominance and Recessiveness.

Law of Segregation

Each organism carries two alleles for every gene, one from each parent. During gamete formation, these alleles separate so that each gamete receives only one allele.

Law of Independent Assortment

Genes located on different chromosomes are inherited independently of one another, unless the genes are close together on the same chromosome.

Dominance and Recessiveness

Some traits are dominant and expressed in the phenotype even if only one copy of the dominant allele is present. Recessive traits only appear when both alleles are recessive.

DNA (Deoxyribonucleic Acid)

The genetic material composed of two long strands of nucleotides twisted into a double helix, providing the instructions for growth, reproduction, and function in all living organisms.

Adenine (A)

Pairs with Thymine (T) in DNA.

Cytosine (C)

Pairs with Guanine (G) in DNA.

Replication

The process by which DNA is copied before a cell divides, ensuring each daughter cell receives a complete set of genetic material.

Expression

DNA is used to synthesize proteins through the processes of transcription (DNA to mRNA) and translation (mRNA to protein).

Central Dogma of Molecular Biology

Describes the flow of genetic information in biological systems, outlining how DNA is used to produce proteins, involving transcription and translation.

Transcription

The process by which a gene's DNA sequence is copied into mRNA (messenger RNA) in the nucleus, catalyzed by RNA polymerase.

Translation

The mRNA is transported to the ribosome, where it is translated into a protein. The ribosome reads the mRNA codons and assembles the corresponding amino acids into a polypeptide chain.

Point Mutations

A change in a single nucleotide in a DNA sequence.

Substitution

One base is replaced by another.

Insertion

One or more bases are added to a DNA sequence.

Deletion

One or more bases are removed from a DNA sequence.

Frameshift Mutations

Caused by insertions or deletions that shift the reading frame of the gene, often leading to nonfunctional proteins.

Chromosomal Mutations

Changes to the structure or number of chromosomes.

Duplication

A segment of a chromosome is repeated.

Inversion

A chromosome segment is reversed.

Translocation

A segment of one chromosome is moved to another chromosome.

Silent Mutations

Do not affect the amino acid sequence of a protein because of redundancy in the genetic code.

Missense Mutations

A point mutation that changes one amino acid in the protein sequence.

Nonsense Mutations

A mutation that creates a stop codon, prematurely ending protein synthesis.