Life Science “The Molecular Basis of Heredity”
Amino Acid Any of the organic acids that are the chief component of proteins, either manufactured by cells or ingested by the organism. Click here to reveal the definition!
Anticodon A three-based sequence on tRNA that binds to a complementary three-base sequence on mRNA. Click here to reveal the definition!
Autosomal Chromosome Any of the non-sex chromosomes. Click here to reveal the definition!
Chromatin Numerous strands of DNA, coiled and bunched together; the individual strands that make up chromosomes. Click here to reveal the definition!
Chromosome Any of the tubelike bodies within the nucleus containing DNA and protein; chromosomes carry the genetic code for an organism’s inherited characteristics. Click here to reveal the definition!
Codon A three-based sequence on mRNA that tRNA uses to provide the correct amino acid. Click here to reveal the definition!
Daughter Cell A cell produced from a parent cell by mitosis or meiosis. Click here to reveal the definition!
Deoxyribonucleic Acid (DNA) A double-stranded nucleic acid molecule that contains the genetic code. Click here to reveal the definition!
Diploid A cell that has two sets of chromosomes. Click here to reveal the definition!
DNA Polymerase An enzyme the moves along a stand of DNA and repairs or replicates the DNA. Click here to reveal the definition!
Dominant Allele The form of a trait that is always expressed when at least one allele for it is present. Click here to reveal the definition!
Fertilization The process of union of two gametes, in which the diploid chromosome number is restored. Click here to reveal the definition!
First Filial (F 1 )Generation The first hybrid offspring in a genetic cross fertilization. Click here to reveal the definition!
Gamete A sex cell containing only half the usual number of chromosomes; in sexual reproduction, the genetic material from the male gamete (sperm) combines with genetic material from the female gamete (egg) to create new offspring. Click here to reveal the definition!
Gene A DNA sequence that codes for a particular protein and, therefore, a specific trait. Click here to reveal the definition!
Gene Expression The appearance of a particular trait in an organism through the process of DNA transcription and protein synthesis. Click here to reveal the definition!
Genotype The combination of dominant and recessive genes (alleles) in an organism’s cells. Click here to reveal the definition!
Germ Cell A cell that undergoes meiosis to produce gametes. Click here to reveal the definition!
Haploid A cell, such as a gamete, that has only one set of chromosomes. Click here to reveal the definition!
Helicase A class of enzyme that separates strands of nucleic acid at the start of DNA replication and RNA transcription. Click here to reveal the definition!
Homologous Similar or matched in appearance or structure. Click here to reveal the definition!
Meiosis A process that divides a cell’s nucleus, resulting in sex cells (gametes) that have half the chromosomes of a regular cell. Click here to reveal the definition!
Messenger RNA (mRNA) A type of RNA that transcribes a gene and then carries that information to the ribosomes for protein synthesis. Click here to reveal the definition!
Mitosis The process within cell division by which the original nucleus gives rise to two identical daughter nuclei, each with the same number of chromosomes as the original nucleus; this type of division is required for cell growth and repair. Click here to reveal the definition!
Nucleotide The basic unit of nucleic acid; made of sugar, a phosphate group, and a nitrogenous base; a ringlike structure of carbon, hydrogen, and nitrogen. Click here to reveal the definition!
Parent Cell A cell that gives rise to daughter cells through mitosis and meiosis. Click here to reveal the definition!
Parent (P) Generation The homozygous parents in a genetic cross- fertilization; their offspring are called the F 1 generation. Click here to reveal the definition!
Pedigree A chart showing heritable traits in parents and offspring; may contain information of individuals’ phenotypes or genotypes. Click here to reveal the definition!
Phenotype A physical trait of an organism that results from its genetic makeup. Click here to reveal the definition!
Punnett Square A grid used to show the possible gene combinations from the crossing of two genotypes. Click here to reveal the definition!
Recessive Allele A trait that is expressed only when a dominant allele is not present. Click here to reveal the definition!
Replication A process in which a cell makes a copy of its DNA before dividing. Click here to reveal the definition!
Ribonucleic Acid (RNA) Any of the nucleic acids containing ribose and replacing thymine and uracil that assist in protein manufacture and cellular control. Click here to reveal the definition!
RNA Polymerase An enzyme that reads DNA during transcription and combines complementary bases into an mRNA strand. Click here to reveal the definition!
Second Filial (F 2 ) Generation Offspring the result from interbreeding a hybrid F 1 generation. Click here to reveal the definition!
Sex Chromosome A chromosome that determines sex; in human, a female has two X chromosomes and a male has one X and one Y chromosome. Click here to reveal the definition!
Somatic Cell Any of the cells that make up the body tissues and contains a complete set of a organism’s chromosome pairs; all cells except gametes. Click here to reveal the definition!
Transcription The first stage of gene expression during which mRNA is made; the process that occurs when a DNA sequence is encoded as an mRNA sequence. Click here to reveal the definition!
Transfer RNA (tRNA) An RNA molecule that follows the codes of the mRNA to assemble amino acids into proteins. Click here to reveal the definition!
Translation The second stage of gene expression during which two kinds of RNA work together to assemble amino acids into proteins. Click here to reveal the definition!
Zygote A cell produced by the union of two gametes. Click here to reveal the definition!