Midterm Vocabulary PDF

Genetics - the study of heredity Gamete- sex cell Fertilization- process in sexual reproduction in which male and female reproductive cells join to form a new cell Trait- specific characteristics of an individual Hybrid- offspring of crosses between parents with different traits Gene- sequence...

Genetics - the study of heredity Gamete- sex cell Fertilization- process in sexual reproduction in which male and female reproductive cells join to form a new cell Trait- specific characteristics of an individual Hybrid- offspring of crosses between parents with different traits Gene- sequence of DNA that codes for a protein and determines a trait Allele- one of a number of different forms of a gene Principle of dominance- some alleles are dominant and others are recessive Segregation- separation of alleles during gamete formation Probability- the likelihood that a particular event will occur Homozygous- having two identical alleles for a particular gene Heterozygous- having two different alleles for a particular gene Phenotype-physical characteristics of an organism Genotype- genetic makeup of an organism Punnett square- diagram that can be used to predict the genotype and phenotype combinations of a genetic cross Independent assortment- states that genes for different traits can segregate independently during the formation of gametes Incomplete dominance- situation in which one allele is not completely dominant over another allele Codominance- situation in which the phenotypes produced by both alleles are completely expressed Multiple alleles- a gene that has more than two alleles Polygenic trait- trait controlled by two or more genes Homologous chromosomes- chromosomes in which one set comes from the male parent and one set comes from the female parent Diploid- a cell that contains two sets of homologous chromosomes Meiosis- process in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes into a diploid cell Tetrad- structure containing four chromatids during meiosis Crossing over- process in which homologous chromosomes exchange portions of their chromatids during meiosis Zygote- fertilized egg Transformation- a process in which one strain of bacteria is changed by a gene or genes from another strain of bacteria Bacteriophage- kind of virus that infects bacteria Base pairing- principle that bonds in DNA can form only between adenine and thymine and between guanine and cytosine Replication- process of copying DNA prior to cell division Telomere- repetitive DNA at the end of a eukaryotic chromosome DNA polymerase- principal enzyme involved in DNA replication RNA (ribonucleic acid)- single-stranded nucleic acid that contain the sugar ribose Messenger RNA- type of RNA that carries copies of instructions for the assembly amino acids into proteins from DNA to the rest of the cell Ribosomal RNA- type of RNA that combines with proteins to form ribosomes Transfer RNA- type of RNA that carries each amino acid to a ribosome during protein synthesis Transcription- synthesis of an RNA molecule from a DNA template RNA polymerase- enzyme that links together the growing chain of RNA nucleotides during transcription using a DNA strand as a template Promoter- specific region of a gene where RNA polymerase can bind to begin transcription Intron- sequence of DNA that is not involved in coding for a protein Exon- expressed sequence of DNA; codes for a protein Polypeptide- long chain of amino acids that makes proteins Genetic code- collection of codons of mRNA, each of which directs the incorporation of a particular amino acid into a protein during protein synthesis Codon- group of three nucleotide bases in mRNA that specify a particular amino acid to be incorporated into a protein Translation- process by which the sequence of bases of a mRNA is converted into the sequence of amino acids of a protein Anticodon- group of three bases on a tRNA molecule that are complementary to the three bases of a codon of mRNA Gene expression- process by which a gene produces its product and the product carries out its function Mutation- change in the genetic material of a cell Point mutation- gene mutation in which a single base pair in DNA has been changed Frameshift mutation- mutation that shifts the "reading frame' of the genetic message by inserting or deleting a nucleotide Mutagen- chemical or physical agents in the environment that interact with DNA and may cause a mutation polyploidy - condition in which an organism has extra sets of chromosomes Operator- short DNA region, adjacent to the promoter RNA interference- introduction of double stranded RNA into a cell to inhibit gene expression Homeobox gene- a DNA sequence of approximately 130 base pairs, found in many homeotic genes that regulate development Hox gene- a group of homeotic genes clustered together that determine the head to tail identity of body parts in animals Genome- entire set of genetic information that an organism carries in its DNA Karyotype- micrograph of the complete diploid set of chromosomes grouped together in pairs, arranged in order of decreasing size Sex chromosome- on of two chromosomes that determines an individual's sex Autosome- chromosome that is not a sex chromosome Sex-linked gene- gene located on a sex chromosome Pedigree- chart that shows the presence or absence of a trait according to the relationships within a family across several generations Nondisjunction- error in meiosis in which the homologous chromosomes fail to separate properly Restriction enzyme- enzyme that cuts DNA at a sequence of nucleotides Selective breeding- method of breeding that allows only the organisms with desired characteristics to produce the next generation.