Chapter 9: Traits of Living Things
 acquired trait
o characteristic that an organism develops after it is born
 adaptation
o a trait or characteristic that helps an organism survive in its environment
 asexual reproduction
o production of offspring from only one parent
 chromosome
o short, thick coil of DNA
 DNA
o molecule found in the nucleus of a cell and shaped like a double helix; carries and transfers genetic
information
 dominant
o trait that is expressed when an organism receives genes for two different forms of a trait
 gene
o short segment of DNA that determines an organism’s inherited traits
 heredity
o genetic transfer of characteristics from parents to offspring
 hybrid
o organism that has two different genes for the same trait
 mutation
o change in the genes of an organism
 nucleotide
o basic structural unit of DNA
 recessive
o trait that is not expressed when an organism receives genes for two different forms of a trait
 selective breeding
o practice of breeding plants and animals for desirable traits
 sexual reproduction
o production of offspring by the union of male and female gametes
 allele
o one of several forms of a gene that determine different forms of genetic traits and occupy identical places on
two chromosomes.
 genotype
o the whole set of genes of an individual or group
 phenotype
o the visible characteristics of a plant or animal that result from the combined effects of the genes and the
environment
 trait
o an inherited characteristic
 heterozygous
o having at least one gene pair that contains different genes
 homozygous
o having at least one gene pair that contains identical genes