Genetic Variation and Heredity
How do heterozygous individuals compare to those that are homozygous for each of the alleles.
Heterozygous: 2 different alleles (1 uppercase, 1 lowercase)
Homozygous: 2 of the same alleles (2 uppercase or 2 lowercase)
What is a restriction enzyme?
Enzymes that cut DNA at specific nucleotide sequences.
What are the 5 lines of evidence for evolution?
What is artificial selection?
A process by which humans intentionally breed organisms based on which traits they want to pass on to the next generation.
How can non-native and invasive species affect the population of native species?
Non-native species out-compete native species for resources, reducing their population and even causing extinction.
What is codominance?
Codominance: neither allele is dominant to the other; when both alleles are present, each trait is expressed equally but do not mix.
What is gene therapy?
The transfer of DNA into an individual's body cells.
What are homologous structures? Give two examples.
Structures that evolved from a common ancestor and show similar structures, but may serve different purposes.
Ex: human arm, sea lion flipper, bird wing
What is natural selection?
The process in which individuals with traits that work best in their environment (adaptive trait) tend to produce more offspring.
How might rapid environmental change due to human impact, like prolonged droughts, affect species?
It will cause species populations to decline or even go extinct
A heterozygous tall plant (Tt) is crossed with a short plant (tt). What are the possible phenotypes of their offspring? What is the probability of each phenotype?
Possible phenotypes: tall, short
Probability: 50/50
What does gene therapy have the potential to treat?
To treat a disease or correct a genetic disorder.
What are analogous structures? Give two examples.
Structures in different species that have similar functions but do not come from a common ancestor; developed to serve the same purpose, but formed in different ways.
Ex: bird wings and insect wings are both used to fly, but developed from different structures and ancestors.
What are adaptations? Why do adaptations tend to become more common in a population over time?
Adaptations: trait/characteristic that allows an organism to better survive in its environment.
They increases survival and reproduction, so they get passed on more frequently.
Which of the following is most likely to lead to environmental degradation - use of fossil fuels, use of solar energy, reforestation?
Use of fossil fuels.
Feather color in some parrots shows codominance, with R alleles producing red feathers and B alleles producing blue feathers. What would a heterozygous (RB) parrot look like?
Red and blue
How do vaccines confer/provide immunity?
By stimulating the production of antibodies that recognize specific antigens.
What are vestigial structures? Give two examples.
Structures that no longer serve a purpose, but had a function in a species' ancestor.
Ex: tailbone, wisdom teeth, appendix
What are the three conditions that are required in a population for natural selection to occur?
Overproduction in populations: More are born into a population than can survive
Variation & adaptation: individuals are born with slightly different traits, some of which may be more useful for survival in the environment (adaptation)
Survival of the fittest: Individuals with adaptations that better help them survive (high fitness), are more likely to survive and reproduce
Which of the following human activities will most directly affect biodiversity - air pollution, water pollution, or habitat destruction?
Habitat destruction.
What is complete dominance?
When one allele completely masks (hides) another allele for the same gene.
What is the difference between a viral-vector vaccine and an inactivated vaccine?
Viral-Vector Vaccine: a safe virus that carries genetic material from the pathogenic virus, which the body uses to build antigens causing an immune response.
Inactivated Vaccine: whole, inactive virus particles are given, building immunity without risk of infection.
How do vestigial structures provide evidence for evolution?
The fact that the structure once was there, but no longer is, shows how a species has evolved over time.
What is the difference between disruptive selection and stabilizing selection?
Disruptive: the ‘extreme’ versions of a trait are favored over the intermediate form, and become more common over time (example: white fur and black fur are each more common than gray fur)
Stabilizing: The intermediate form a trait becomes more common (example: gray fur is more common than either white fur or black fur)
How could creating protected natural reserves and wildlife refuges affect biodiversity?
It would help protect biodiversity (reduce the loss of biodiversity).