BIOL 300 Progress Test 1

Ch 1, 2, and 7

agarose

An inert material derived from agar that is mixed with buffer and used to form gels for gel electrophoresis.

allele

A specific version of a gene (like A or a)

anticodon

The nucleotide triplet sequence of transfer RNA that pairs with an mRNA codon sequence in translation.

chromosome

A single DNA molecule and associated proteins that contains some or all of the genetic information of an organism

clade

In phylogenetics, a group of organisms defined by characteristics that are unique to the group and distinguish the group from others.

cladistics

The classification of organisms by characteristics that are unique to the group and distinguish it from other groups. Involves branching of new species from ancestral species. See also clade.

coding strand

The nontemplate strand of DNA that has the same polarity as its transcript and the same sequence, except for T in DNA and U in RNA.

codon

The nucleotide triplet of mRNA that encodes a single amino acid.

cytoplasmic inheritance

Transmission of genes outside of the nucleus, e.g., in the mitochondrial or chloroplast genome.

diploid number

The characteristic number of chromosomes (2n) in somatic cell nuclei during the diploid phase of the eukaryotic life cycle. Equal to twice the haploid (n) number of chromosomes found in the nuclei of gametes of sexually reproducing diploid species.

electrophoretic mobility

A measurement of (1) the distance of migration or (2) the speed of migration of a nucleic acid or protein in gel electrophoresis.

exon

A nonintron segment of the coding sequence of a gene. Joined together following intron splicing, exons correspond to the mRNA sequence that is translated into a polypeptide.

gamete

The reproductive cells produced by male and female reproductive structures; sperm or pollen in male animals and plants and eggs in females.

gene

The physical unit of heredity, composed of a DNA sequence that is transcribed and encodes a polypeptide or another functional molecule.

genetic code

The universal set of correspondences of mRNA codons to amino acids. Used in translation to synthesize polypeptides.

genome

The entire complement of DNA sequences in a chromosome set of an organism.

genomics

The study of the structure, function, composition, and evolution of genomes.

genotype

(1) The genetic composition of an organism or a cell (i.e., all the alleles of all the genes). (2) The alleles of a single gene or a specified set of genes in a cell or organism.

haploid

Possessing a single set of chromosomes (n); a cell or organism that possesses one

homologous chromosomes

Chromosomes that synapse (pair) during meiosis. Chromosomes with the same genes in the same order. Also known as homologs.

homology

Evolutionarily related, having descended from a common ancestor.

homoplasmy

The presence of one allelic version of DNA in the organellar genomes of a cell.

ingroup

A species within a clade used to compare with other members of the clade.

intron

Intervening sequences between the exons of many eukaryotic genes. Present in DNA and pre

LUCA

An acronym for the last universal common ancestor, meaning the last ancestor from which all living organisms are descended.

megabase (Mb)

Equal to 1,000,000 nucleotide bases. Refers to DNA or to RNA molecules or fragments.

Mendelian genetics

Referring to genetic applications and analyses using the law of segregation and the law of independent assortment originally described through experiments and analysis by Gregor Mendel.

messenger RNA (mRNA)

A form of RNA transcribed from a gene and subsequently translated to produce a polypeptide or protein.

metabolomics

The study of proteins, processes, and interactions involved in the metabolism of organisms.

molecular genetics

The subfield of genetics that studies hereditary transmission, variation, mutation, and evolution through the analysis of nucleic acids and proteins.

monophyletic group

A group of organisms with a single common ancestor.

northern blotting

A method for transferring mRNA from an electrophoresis gel to a permanent membrane or filter.

nucleoid

The region of bacterial and archaeal cells (or mitochondria or chloroplasts) where the main chromosome resides.

origin of migration

The starting point of nucleic acid or protein migration in gel electrophoresis.

outgroup

A species related to members of a clade but outside the clade; used to root the clade.

parental strand

The DNA strand acting as a template to direct the synthesis of a new (“daughter”) strand of DNA.

peptide bond

A type of covalent bond that joins amino acids in polypeptide chains. Formed between the amino end of one amino acid and the carboxyl end of the adjoining amino acid.

phenotype

(1) The observable physical characteristics or traits of an organism. (2) The physical manifestation of a specific genotype.

phosphodiester bond

A type of covalent bond formed between two nucleotides in a nucleic acid strain. Formed between the phosphate group of one nucleotide and the OH of the adjacent nucleotide.

phylogenetic tree

A diagram of evolutionary relationships among organisms or genes based on morphological or molecular characteristics.

polyacrylamide

A synthetic compound mixed with buffer and used to form electrophoresis gels.

polypeptide

A chain of amino acids joined by peptide bonds. Formed at ribosomes during translation.

polyploidy

The presence of more than two complete sets of chromosomes in a genome. See also allopolyploidy and autopolyploidy.

promoter

A regulatory sequence of DNA near the end of a gene that acts as the binding location of RNA polymerase and directs RNA polymerase to the start of transcription.

protein

A string of amino acids encoded during translation of mRNA and linked together by peptide bonds. See also polypeptide.

proteome

Set of the proteins in a cell, tissue, or organism.

proteomics

The study of all the proteins, collectively known as the proteome, within a cell, tissue, or organism.

reverse transcription

The process of DNA synthesis from an RNA template by the enzyme reverse transcriptase.

ribonucleic acid (RNA)

A family of polynucleotides that are transcribed from DNA. RNAs are composed of nucleotides containing the sugar ribose, one or more phosphate atoms, and one of four nitrogenous bases (A, G, C, and U).

ribosomal RNA (rRNA)

A group of RNA molecules that compose part of the structure of ribosomes.

ribosome

Ribonucleoprotein particles, composed of rRNAs and numerous proteins, at which translation takes place.

semiconservative DNA replication

The established method of DNA replication in which each strand of a parental duplex acts as a template for daughter strand synthesis and each daughter duplex is composed of one parental strand and a complementary daughter strand.

shared derived characteristics

Characteristics or traits of organisms that evolve from more ancestral characteristics or traits found in ancestral organisms.

Southern blotting

A laboratory method devised by Edwin Southern for transferring DNA from an electrophoresis gel to a permanent membrane or filter.

start codon

Most commonly AUG, encoding methionine, the first codon translated in polypeptide synthesis.

start of transcription

The DNA location at which transcription begins.

stop codon

One of three codons that bind a release factor instead of base

strand polarity

The orientation of a nucleic acid strand indicating its phosphate and hydroxyl ends.

synaptomorphy

A characteristic present in an ancestral species and shared, perhaps in a modified form, by its evolutionary descendants.

systems biology

Prediction of biological functions of genes based on correlations between different data sets.

template strand

The DNA strand serving as a template for synthesis of a complementary nucleic acid strand.

termination sequence

DNA sequences that serve to stop transcription. Also known as transcription termination.

thymine (T)

One of four nitrogenous nucleotide bases in DNA; one of the two types of pyrimidine nucleotides in DNA.

transcription

The cellular process that synthesizes RNA strands from a DNA template strand.

transcriptome

Set of transcripts present in a cell, tissue, or organism.

transcriptomics

The study of all the transcripts, collectively known as the transcriptome, within a cell, tissue, or organism.

transfer RNA (tRNA)

A family of small RNA molecules that each bind a specific amino acid and convey it to the ribosome, where the anticodon sequence undertakes complementary base pairing with an mRNA codon during translation.

translation

The process taking place at ribosomes to synthesize polypeptides. Complementary base pairing between mRNA codons and tRNA anticodons determines the order of amino acids composing the polypeptide.

transmission genetics

The subfield of genetics concerned with assessment and analysis of gene transfer from parents to offspring. Synonymous with Mendelian genetics.

uracil (U)

One of four nitrogenous nucleotide bases in RNA; one of the two types of pyrimidine nucleotides in RNA.

western blotting

A method for transferring protein from an electrophoresis gel to a permanent membrane or filter. addition rule

artificial cross

fertilization

autosomal dominant inheritance

A pattern of hereditary transmission in which the dominant allele of an autosomal gene results in the appearance of the dominant phenotype.

autosomal inheritance

Hereditary transmission of genes carried on autosomes.

autosomal recessive inheritance

A pattern of hereditary transmission in which the recessive allele of an autosomal gene results in the appearance of the recessive phenotype.

binomial probability

A probability function using two coefficients, a and b, whose sum equals 1 and whose products predict the probability of events.

blending theory of heredity

An obsolete theory of heredity proposing that the traits of offspring are the average of parental traits.

chi

square test ( χ test)

conditional probability

A probability prediction that is dependent on another previous event having taken place.

controlled genetic cross

Genetic crosses controlled by an investigator who usually knows the genotypes and/or phenotypes of the organisms being crossed.

degrees of freedom (df )

The number of independent variables in an experiment. In a chi

dihybrid cross

A cross between organisms that are heterozygous for two loci.

dominant allele

An allele that is expressed in the phenotype if the genotype contains one or more copies of the allele.

dominant phenotype

The phenotype observed in a heterozygous organism that is identical to the phenotype observed in a homozygote. The phenotype produced when an organism is homozygous for the dominant allele or carries a single copy of the dominant allele in the heterozygous genotype. Compare with recessive phenotype.

generation (first filial generation)

The first generation of offspring. In genetic experiments, usually the offspring produced by crossing pure

forked

line diagram

genotypic ratio (1:2:1 ratio)

(1) A ratio or set of relative proportions between organisms with different genotypes. (2) The ratio of 1/4 : 1/2 : 1/4 observed among the homozygous and heterozygous progeny of a monohybrid cross.

heterozygous genotype

A diploid genotype characterized by the presence of two different alleles of a gene.

homozygous genotype

A diploid genotype characterized by the presence of two identical alleles of a gene.

law of independent assortment (Mendel’s second law)

The random distribution of alleles of unlinked genes into gametes.

law of segregation (Mendel’s first law)

The separation of alleles of a gene during gamete formation.

monohybrid cross

A genetic cross between organisms that are heterozygous for one gene.

multiplication rule

See product rule.

parental generation (P generation)

The parents of progeny. In controlled genetic crosses, the parents are pure

particulate inheritance

Mendel’s theory that genetic information is transmitted from one generation to the next as discrete units or elements of heredity.

Pascal’s triangle

A diagram listing the coefficients of a given binomial expansion in which the binomial expression is expanded n number of times.

pedigree

A family tree composed of standard symbols that depicts relationships in successive generations and often displays individual phenotypes.

phenotypic ratio

A ratio or set of relative proportions between organisms with different phenotypes—for example, the ratio of progeny produced by a monohybrid cross (3:1) or a dihybrid cross (9:3:3:1).

prior probability

A statistical prediction of an outcome before the event. In genetics, the prediction of the possible outcomes of a genetic cross based on Mendelian genetics.

probability value (P value)

In the chi square test, the likelihood that a repeat experiment will produce a result as deviant or more deviant than expected in comparison with the experimental result being tested.