Unit 4: AOS 2: Glossary Flashcards
(98 cards)
What is a genotype?
the genetic make-up or the combination of alleles for a particular gene of an organism
What is a Phenotype?
a physical characteristic determined by genotype and environment
What is Genetic diversity?
the genetic variability within a spices
What are adaptations?
the behavioural, physiological and structural features of an organism that help them survive in an environment
What is a population?
a group of individuals of the same species living in the same region at a given time
What are species?
a group of organisms that can interbreed, producing fertile and viable offspring
What is a gene pool?
the sum total of alleles present in a population of organisms
What is an Allele frequency?
the porpution of a particular allele within a population
What is evolution?
a change in the allele frequencies if a population over time
What is a mutation?
A permanent change in the nucleotide sequence of a section of DNA
What is a mutagenic agent?
agents known to cause mutations; e.g some radiation source and chemicals; also called mutagens
What is point mutation?
a change to one base in the nucleotide sequence of a section of DNA; includes base substitutions and frameshift mutations
What is Substitution mutation?
a type of point mutation that occurs when one nitrogenous base in a gene is replaced with another base; includes silent, missense and nonsense mutations
What is a silent mutation?
a mutation where the change in the nucleotide sequence doesn’t change the amino acid that is coded for
What is a Missenese mutation?
a mutation in which the base change in the nucleotide sequence of the DNA changes the amino acid that is coded for; a type of substitution point mutation
What is nonsense mutation?
a mutation that occurs when the base changes in the nucleotide sequence of the DNA codes for a STOP codon, prematurely halting the production of the polypeptide; a type of substitution point mutation
What is frameshift mutation?
a type of point mutation that occurs when one base is inserted into or deleted, causing an incorrect reading of the codons due to a shift in the reading frame
What is block mutation?
a type of mutation that affects large sections of DNA, typically containing multiple genes; also called chromosome mutation
What is Chromosome abnormality?
mutation that involves a whole chromosome, or a change in the number of chromosomes, which can be identifies using a karyotype; e.g aneuploidy and polyploidy
What is Karyotype?
a pictorial representation of chromosomes that allows a geneticist to determine size, banding pattern, shape and number of chromosomes in an individual’s somatic cell; allows the determination of diploid number, gender and chromosomal abnormalities
What is a Aneuploidy?
when a cell has one more or one less chromosome than expected, usually due to non-disjunction
What is Polyploidy?
a condition in which an organism has more than 2 full sets of chromosomes in its cells; more common in plants than animals
What is gene flow?
the exchange of genetic information, specifically alleles, between populations
What is genetic drift?
a random change in allele frequency, occurring naturally in every population, due to chance events