Chapter 2 notecards Flashcards
individuals unique genetic makeup
genotype
directly observable characteristics
phenotype
rodlike structures inside the nucleus of each cell in the body
store and transmit genetic information
chromosome
segments of DNA located along the chromosomes
genes
substance of which genes and chromosomes are made
DNA
when DNA duplicates itself
mitosis
22 pairs of chromosomes that are not sex chromosomes
autosomes
23rd pair of chromosomes, determine sex
sexchromosomes
gametes are formed through _______
meiosis
two forms of the same gene
allele
when a harmful allele is carried on the X chromosome,
______ are more likely to e affected because their sex chromosomes do not match
X-linked inheritance
a pattern of inheritance in which both alleles are expressed, results in a combined trait intermediate between the two alleles
incomplete dominance
many genes influence a characteristic
polygenic inheritance
alleles are imprinted or chemically marked so that one pair member is activated, regardless of its makeup;
genomic imprinting
problems with the 21st chromosome
down syndrome