mendelian genetics Flashcards
(28 cards)
what is a genotype
the composition of a gene for an individual which is determined by the combination of alleles
what is a phenotype
the physical expression of an individuals gene
what are genes
decorate hereditary factors that determine traits. genes make up a DNA which are wrapped around nucleosomes and condenses into a chromatin.
what is a locus
position of a gene in the DNA of a chromosome. the position of a gene is identical with everyone
what are alleles
they are different form of genes.
what are homologous chromosomes
inherited from parents that have the same set of gene. each chromosome in a pair is called a homologue- one from each parent
what are prokaryotes
asexual reproduction. happens in somatic cells and proceed clones. all cells are haploid. mitosis.
what are eukaryotes
sexual reproduction- offspring are genetically different. there are two diploid body cells (two sets of chromosomes). starts at haploid sex cells but fuse to become diploid.
how does mitosis and meiosis work
mitosis: normal cell replacement and growth, diploid maintained at each division. the parents and daughter cells are identical
meiosis: only in sex cells. produce haploid cells. exchange of genetic material through random assortment and crossing over.
explain interphase
where most cells arestart. gwroth phase 1-functioning as what they are. synthesis- chromosome changes from a singular molecule to double DNA molecule. growth phase 2- short interval where some proteins required for cellular replication are produced.
what is the principal of segregation
alleles are separated before gametes are formed as a result of separation of homologous chromosomes.
when two daughter cells forms what happens
they will form a zygote which will be a diploid cell. offsprings will have 50% change of carrying a parents genetic makeup
what is the principal of independent assortment
what happens in meiosis one.
what is the mendelian inheritance important
- assess risk of disease
-agricultural applications
-breeding - evolution and population biology
- paternity testing
what is a monohybrid cross
single gene and looking at two alleles that make up a gene.
what are purebred
homozygous individuals
what is intercross
crossing genes of two homozygous parents .
what are monohybrid drosses
determining the genotype and phenotype of their offspring
what are dihybrid crosses
cross of two pure breeding lines
if given a 9:3:3:1 ration ,was does his mean
its a dyhibrids cross. two genes from two homozygous parents.
what are back crosses and test crosses
backcrosses: to reinforce a trait- cross with dominant desired traits- determines genotype of F1 progeny. cross F1 hybrid with one of its parents.
test crosses: used to dermic where an individuals with the dominant phenotype is homozygote or heterozygous. you do this by crossing an individual of dominant phenotype with a homozygous recessive individual
what is incomplete dominance
third trait: combined. red plus white is pink
what is co dominance
both present. can be affected by environmental factors.
if smth is written as BB ob Bb, what type of dominance is it
complete dominance
