definitions Flashcards
define alleles
alleles are different forms of genes
what is a gene
a gene is a dna segment that contributes to phenotype/function OR the physical and functional unit for inheritance
define heterozygous
heterozygous refers to the 2 different alleles expressed present in a trait
define homozygous
homozygous is when 2 identical alleles are present in the same trait
examples for homozygous and heterozygous
homozygous = BB or bb heterozygous = Bb
what is a nucleotide
nucleotides are dna subunits but more specifically are a sugar molecule, nitrogenous base and phosphate
define the purpose of mitosis
the purpose of mitosis is cell regeneration, growth and asexual reproduction
define the purpose of meiosis
the purpose of meiosis is to produce gametes (sperm and egg cells) which factor in sexual reproduction
what is the difference between a haploid and diploid cell
a haploid cell contains a single set of chromosomes whereas a diploid cell contains 2 sets of chromosomes
what is a genotype
a genotype is the genetic characteristics and the combination of alleles in a gene
what is a phenotype
a phenotype is the observable physical properties of an organism (appearance, behaviour and development)
what is co-dominance
co-dominance refers to the traits that are equally dominant and visible in a child
define a chromosome
a chromosome has a thread-like dna structure that is present in the nucleus and carries genetic information and genes
what are gametes
gametes are sex cells but can also be formerly known as an organism’s reproductive cell
what are the female and male gametes
females = the egg male = sperm
define a karyotype
a karyotype is a pictorial representation of the chromosomes paired up/arranged which can be used to find chromosomal/genetic abnormalities/disorders
what is a codon
a codon is a sequence of 3 nucleotides that together form a unit of genetic code for a dna or rna molecule
what is a punnett square
a punnett square is used to predict the genotypes of an offspring from a breeding event
what is a test cross
a test cross is a way to explore the genotype of an organism
what are somatic cells
somatic cells are body cells except for the egg and sperm cells. they are also diploid
example of a somatic cell
an example of a somatic cell would be skin cells and blood cells
what is a triplet
a triplet are the 3 dna bases that code for an amino acid
what is a pedigree
a pedigree is a chart used to study the inheritance over generations
what are hydrogen bonds
hydrogens bonds are chemical bonds that hold the two strands of dna together
