Life Science Search “book biology quick review”
Classifying the Diversity of Life • There are three domains of living things:
Cell Theory • the cell is the smallest unit of life; all cells arise from pre-existing cells
Some Terminology • Same alleles = homozygous • Different alleles = heterozygous Homologous Chromosome Pair Sister Chromatids
Dominant and Recessive • In the heterozygous condition, one allele gets expressed and the other one doesn’t. • The allele that is expressed is said to be dominant. • The one that is not expressed is recessive.
Homozygous and Heterozygous • Homozygous dominant = AA = dominant trait expressed • Heterozygous = Aa = dominant trait expressed • Homozygous recessive = aa = recessive trait expressed
Genotype and Phenotype • Genotype is the set of alleles an individual has for a character. • Phenotype is the trait that is expressed.
Brown eyes is dominant to blue in humans. A man with brown eyes (whose father had blue eyes) marries a woman with blue eyes. Predict the genotype and phenotype frequencies of their offspring.
Acquired vs Inherited Traits • Inherited – passed via DNA in sperm/egg from parents; e.g. eye color • Acquired – not inherited; e.g. a learned behavior; strengthening muscles; tattoo
Evolution When the monster came, Lola, like the peppered moth, remained motionless and undetected. Harold, of course was immediately devoured.
Morphological adaptation – physical features • Physiological adaptation – chemical reactions • Behavioral adaptation - behaviors
Genetic Variation Overproduction of Offspring Differential Reproduction Change in frequency of traits
Evolution accounts for both the unity (things in common) and diversity (lots of different types) of life
Behavior • Learned vs innate behaviors (instinct)