Topic 6: heredity (inheritance) Flashcards
what is inheritance?
-transfer of genetically determined characteristics from one generation to the next
what is genetics?
-the study of inheritance
how many homologous pairs of chromosomes are autosomal?
-22
what are autosomal characteristics
-body characteristics
what is the final pair of chromosomes determining?
-sex
-male = XY
-female = XX
what are alleles?
-genes occupying the same locus on a homologous chromosome
what are the two classifications of alleles?
-homozygous
-heterozygous
what does it mean to be homozygous?
-same allele of a particular gene on a homologous chromosome
-both alleles express the same version of the trait
-ex:blond hair (bb) black hair (BB)
what does it mean to be heterozygous?
-different allleles of the same gene
-alleles code for different expressions of the same trait
-ex: Bb
what is a genotype?
-catalogue of a persons genes
-your genetic makeup
-ex: Bb
what is a phenotype?
-expression of a genotype to give observable characteristics
-ex: black hair
what is a dominant allele?
-expressed as a capital letter
-expressed in phenotype regardless of the other allele
-ex: BB or Bb (black hair)
what is a recessive allele?
-expressed as a lower case letter
-expressed in phenotype only if present on both alleles
-ex: bb (blonde hair)
what are punnett squares?
-determines the probability of inheritance
-predicts the offsprings genotype and phenotype
what are examples of X-linked inheritance characteristics?
-hemophilia
-colour blindness
-Duchenne’s muscular dystrophy
