Plant Genetics and Genetic Screening - AS Biology

A comprehensive set of vocabulary flashcards covering key concepts in inheritance, mutations, genetic disorders, and genetic screening.

Mutation

A change in the sequence of bases in a DNA molecule.

Substitution Mutation

A mutation that occurs when a base in the DNA sequence is randomly swapped for a different base.

Silent Mutation

A mutation that does not alter the amino acid sequence of the polypeptide due to the degenerate nature of the genetic code.

Missense Mutation

A mutation that alters a single amino acid in the polypeptide chain.

Nonsense Mutation

A mutation that creates a premature stop codon, causing an incomplete polypeptide chain.

Insertion Mutation

A mutation that occurs when a nucleotide is added into the DNA sequence.

Deletion Mutation

A mutation that occurs when a nucleotide is removed from the DNA sequence.

Frameshift Mutation

A mutation that shifts the reading frame of the genetic code, altering all subsequent amino acids.

Homozygous

Having two identical alleles for a specific gene.

Heterozygous

Having two different alleles for a specific gene.

Genotype

The genetic makeup of an organism; the alleles it possesses.

Phenotype

The observable characteristics of an organism, determined by its genotype.

Dominant Allele

An allele that is expressed in the phenotype even when only one copy is present.

Recessive Allele

An allele that is only expressed in the phenotype when two copies are present.

Codominance

A type of inheritance where both alleles contribute equally to the phenotype.

Pedigree Diagram

A chart that shows the inheritance patterns of a particular trait across generations.

Cystic Fibrosis

A genetic disorder caused by a mutation in the CFTR gene, leading to thick, sticky mucus production.

Preimplantation Genetic Diagnosis (PGD)

Testing embryos for genetic disorders before implantation during IVF.

Prenatal Testing

Testing a fetus for genetic disorders during pregnancy.

Chorionic Villus Sampling (CVS)

A procedure involving the removal of cells from the placenta for genetic analysis.

Amniocentesis

A procedure to obtain a sample of amniotic fluid for genetic testing.

Mutagen

An agent that increases the likelihood of a mutation occurring in DNA.

Gene

A segment of DNA that codes for a polypeptide.

Chromosome

A long DNA molecule containing many genes.

Allele

Different forms of a gene that occupy the same locus.

Locus

The specific location of a gene on a chromosome.

Genetic Disorder

A disease caused by a mutation in one or more genes.

Carrier

An individual who has one copy of a recessive allele and does not express the trait.

Sex-linked Trait

A trait associated with a gene located on a sex chromosome.

Natural Selection

The process through which advantageous traits become more common in a population.

Polypeptide

A polymer of amino acids that forms proteins.

Gene Therapy

A technique that modifies genes to treat or prevent diseases.

Gene Mapping

Determining the location of genes on chromosomes.

Epigenetics

The study of changes in gene expression that do not involve changes to the underlying DNA sequence.

Intron

A non-coding segment of a gene that is removed during RNA processing.

Exon

A coding segment of a gene that is retained in the final RNA product.

Translation

The process by which ribosomes synthesize proteins based on mRNA sequence.

Transcription

The process of synthesizing RNA from a DNA template.

Mitosis

A type of cell division that results in two identical daughter cells.

Meiosis

A type of cell division that reduces chromosome number by half, producing gametes.

Genetic Counseling

A service that provides information and support to individuals regarding genetic disorders.

Designer Babies

Theoretical babies whose genetic characteristics have been artificially selected.

Ethical Dilemma

A situation where a difficult choice has to be made about conflicting values.

Polygenic Trait

A trait controlled by two or more genes.

Single Nucleotide Polymorphism (SNP)

A variation at a single position in a DNA sequence among individuals.