Teacher Key for pages 51-64
1. Evolution: Change in characteristics of a population from one
generation to the next.
2. Overproduction: each species produces more individuals that can
survive to maturity.
3. Genetic Variation: individuals may differ in traits such as size,
color, strength, speed, etc.
4. Struggle to Survive: individuals must compete with each other for
limited resources- they must be harmed by predation, disease, etc
5. Differential Reproduction: individuals have certain traits that are
more likely to survive and reproduce than individuals that lack
those traits.
6. Speciation: the formation of a new species as a result of evolution
by natural selection.
7. Alleles: a variant form of a gene.
8. Immigrants: new individuals joining a population, which adds
alleles to a population.
9. Emigrants: individuals leave, taking alleles away from a
population.
10.Inbreeding: mating with relatives. A type of non-random mating
that causes lower frequency of alleles.
11.Homozygous: organisms that have two or the same identical
alleles for a trait, such as TT or tt.
12.Heterozygous: Organisms that have two different alleles for a
trait, such as Tt.
13.Genetic Drift: change in allele frequency occurs randomly as of
the frequency was drifting. For example, a small population that is
isolated from each other.
14.Migration: the movement of individuals to or from a population.
15.Inherited Traits: Certain forms of a trait become more common in
a population because more individuals in the population carry the
alleles for those forms.
16.Recessive alleles: The weaker allele, for example dd or blue eyes.
17. Dominant alleles: The stronger allele, for example DD or Dd or
traits such as brown eyes.
18. Homologous chromosomes: Two chromosomes, one from mom
and one from dad that have relatively the same length and general
appearance. For example your autosomes, chromosomes 1-22.
19. Law of Segregation: Mendel’s first law- 1. Organisms inherit two
copies of each gene (one from each parent). 2. Organisms donate
only one copy of each gene in their gametes. Two copies of each
gene segregate or separate during gamete formation.
20. Law of Independent Assortment: Mendel’s second law of
genetics states that allele pairs separate independently of each other
during gamete formation or meiosis. Different traits appear to be
inherited separately.