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Week 29 Study Guide
Define
Trait- A characteristic that an organism can pass on to its offspring through its genes
DNA- The genetic material that carries information about an organism and is passed from
parent to offspring
Chromosome-A thread like cellular structure that carries the information that controls inherited
characteristics
Alleles- The different forms of a gene
Gene- A segment of DNA on a chromosome that codes for a specific trait
Dominant Alleles- An allele whos trait always shows up in the organism when the allele is
present
Recessive Alleles- An allele that is masked when a dominant allele is present
Genotype- An organism’s genetic makeup or allele combinations
Phenotype- An organism’s physical appearance or visible traits
Heterozygous/Hybrid- Having two different alleles for a trait.
Homozygous/Pure- Having two identical alleles for a trait
Mutation- A change in a gene or a chromosome
Asexual Reproduction- The production of offspring by a single parent, without the union of a
sperm cell or egg cell
Sexual Reproduction- The reproductive process that involves two parents to combine their
genetic material to produce a new organism which differs from both parents
Punnett Square- A chart that shows all possible combinations of alleles that can result from a
genetic cross.
Adaptation- A characteristic that helps an organism to survive in its environment or reproduce.
Competition- The struggle between organisms for the limited resources in a habitat.
Evolution- The gradual change in a species over time.
Natural Selection – The process by which individuals that are adapted to their environment are
more likely to survive and reproduce than other members of the same species
Selective Breeding- The process of selecting a few organisms with desired traits to serve as the
parents of the next generation
1. What adaptation allows a fish to exchange oxygen and carbon dioxide?
Gills
2. What adaptation allows a bird to be lite enough to fly?
Hollow Bones
3. In asexual reproduction there are _1____ Parent(s) and the off spring are
(Uniform / Diverse).
4. In sexual reproduction there are __2___ Parent(s) and the off spring are
(Uniform / Diverse).
5. What is the genotype of a Father that is Homozygous Dominate for
dimples? DD
6. What is the genotype for a Mother that is Heterozygous for brown eyes? Bb
7. Why do some birds have bill like a duck and some birds have a long narrow
probing beak like a humming bird?
The bird’s beaks are adapted to what they eat
8. If birds are on an island with lots of seeds and very little else to eat, which
bird will survive the best and pass their genetics on? A bird with a strong
beak or a bird with a long narrow beak? Why? A bird with a strong beak
would survive better and reproduce because they are better adapted to eat
seeds.
9. Explain what natural selection is and give an example. Natural selection is
the mechanism that drives evolution. The organisms that can out compete
other organisms for food, water, shelter, space and mates, get to survive
and probably mate, passing on their traits to the next generation. Keeping
the traits that help them survive.
10. Explain what selective breeding is and give an example. The process of
selecting a few organisms with desired traits to serve as parents for the
next generation. Examples: If you want big cattle to take to market, breed
two big cows. If you want a chicken that lays more eggs breed the hens
that lay more eggs.
Put an I in the blank if it is an inherited trait and an L in the blank if it is a learned
trait.
Making Pizza __L___ Having brown Eyes __I___ Playing catch __L___
Walking__L___ Having dimples__I___ Reading__L____ Being Tall___I____