DNA Key Words Flashcards
(22 cards)
Alleles
Different forms of a gene which occupy the same relative positions on a pot of homologous chromosomes
Artificial selection
A method used by humans to produce plants and animals with desired qualities
Asexual reproduction
The process resulting in the production of genetically identical offspring from one parent, without the fusion of gametes
Codominance
A condition where both alleles express themselves in a hybrid, as they are both either dominant or recessive to one another
Continuous variation
Traits with phenotypes ranging from one extreme to the other
It is brought about by combined effects of many genes
It is affected by environmental conditions Intelligence Height Skin colour In humans
Diploid
Cells that contain the full number of chromosomes
Discontinuous variation
Traits that show limited variation in their phenotypes which are easily distinguishable
Usually controlled by only one or a few genes
Not affected by the environment
Dominant
A form of a gene that is expressed and masks the recessive gene
It gives the same phenotype in both homozygous and heterozygous conditions as it expresses itself
Gamete
A reproductive cell containing the haploid number of chromosomes
Gene
A hereditary factor found on a particular locus in a chromosome
Controls a particular characteristic
Codes for a specific protein
Genetic engineering
A technique used to transfer genes from one organism to another
Genotype
The combination of genes in an individual
Haploid
Cells that contain half the number of chromosomes as the parent cells which produced them
Heterozygous
A condition where you have different alleles for a particular trait
Homologous pairs
Chromosomes which have the same genes, shape and length
Homozygous
Having identical alleles for a particular trait
Meiosis
A form of cell division such that the daughter cells contain half the number of chromosomes as the parent cell
Forms gametes (sex cells)
Mitosis
Cell division such that the daughter cell produced contains the same number of chromosomes as the parent cell
Will be diploid
Forms body cells
Mutation
The sudden or spontaneous change in gene structure or a chromosome or even the chromosome number
May be inheritable
Phenotype
The physically expressed trait in an individual
Recessive
A form of gene that expresses itself only in the homozygous condition
Sexual reproduction
The process involving the fusion of two gametes to form a zygote
Results in the production of genetically dissimilar offspring
There will be variation
