Final Exam AP Biology 2 Flashcards
What is a mutation? What causes mutations?
Mutation-a change in an organism’s DNA.Typically a mutation that affect a single gene happen during replication, whereas mutations that affect a group of genes or an entire chromosome happen during meiosis. Mutations are caused when a cell makes a mistake.
What is genetic engineering and how is it useful?
What are some ways genetic engineering has helped advance the field of Biology?
The changing of an organisms DNA to give the organism new traits.
Cloning-a genetically identical copy of a gene or of an organism. Could be useful in growing new organs or extinct species
Gene sequencing-Useful in determining which genes cause disease
Gene therapy-replace a defective or missing gene or the addition a a new gene into a person’s genome to treat a disease.
Transgenic organism-one or more genes from another organism inserted into its genome. Ex-can make plants resistant to frost,diseases and insects.
What is evolution?
What scientist is best known for his contributions to evolution?
What is a species?
Evolution-Change in a species over time. Process of biological change by which descendants come to differ from their ancestors.
Charles Darwin-is most known for evolution
species -A group of organisms so similar to one another that they can reproduce and have fertile offspring.
Define:
- adaptation,
- variation,
- natural selection,
- artificial selection, and
- fitness of an organism.
- Adaptation-sometimes certain variations allow an individual to survive better than other individuals it competes against in the environment. More successful individuals are naturally selected.
- Variation.- is the difference in the physical traits of an individual from those of other individuals in the group to which it belongs
- Natural selection.- is a mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals. In nature the environment is the selective agent.
- Artificial selection.-humans make use of the genetic variations in plants and animals by acting as the selective agent. Humans determine which trait is desirable.
- Fitness -is the measure of the ability to survive and produce more offspring relative to other members of the population in a given environment.
- What are homologous structures and what have they told us about evolution?
- What are analogous structures?
- What are vestigial structures?
- Homologous-are features that are similar in structure but appear in different organisms and have different functions. Homologous structures are different in detail but similar in structure and relation to each other. They offer strong evidence for Common Descent. Ex:forelimbs of tetrapod vertebrates. The forelimbs of humans, bats and moles have several bones that are similar to each other despite their different functions.
- Analogous-structures that perform a similar function, but are not similar in origin. Ex: Bat wings have bones but insect wings do not.
- Vestigial Structures- Remnants of organs or structures that had a function in an early ancestor. They are evidence of common descent and gradual change or shrinkage in unnecessary organs. Ex: Ostrich wings are small as they do not need them to run away from predators.
How does natural selection help the distribution of traits? (pg. 330)
Natural Selection-a mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals. In nature the environment is the selective agent. Alleles associated with favorable phenotypes increase in frequency.
Describe the different types of selection.
- Normal Distribution-When the frequency values are graphed the result is a bell shaped curve. It is highest in the middle and decreases to either side.
- Directional Selection-a type of selection that favors phenotypes at one extreme of a traits range. An extreme phenotype that was once rare in a population becomes more common.
- Stabilizing Selection-the intermediate phenotype is favored and becomes more common in the population.
- disruptive selection-occurs when both extreme phenotypes are favored., while individuals with intermediate phenotypes are selected against by something in nature.
Define genetic drift
genetic drift.-changes in allele frequency due to chance.
How does genetic drift affect populations?
Causes a loss of genetic diversity in a population.
Describe the bottleneck effect and the founder effect.
- Founder effect-is genetic drift that occurs after a small number of individuals colonize a new area. The gene pools of these populations is often very different from the larger population.
- Bottleneck effect-genetic drift that occurs after an event greatly reduces the size of a population.
What is ecology?
Ecology-is the study of the interactions among living things and between living things and their surroundings.
What are the levels of organization that ecologist study?
- Organism-an organism is an individual living thing, such as an alligator.
- Population-a population is a group of the same species that lives in an area, such as all the alligators that live in a swamp.
- Community-a group of different species that live together in one area, such as groups of alligators, turtles, birds, fish and plants that live together in the Florida Everglades.
- Ecosystem-includes all of the organisms as well as the climate, soil, water, rocks and other nonliving things in a given area. An entire ecosystem may live within a decaying log, which may be part of a larger wetland ecosystem. Biome-is a major regional or global community of organisms.
- Biomes are usually characterized by the climate conditions and plant communities that thrive there.
What is the difference between abiotic and biotic factors?
- Biotic factors- are living things, such as plants, animals fungi and bacteria.
- Abiotic factors-are nonliving things such as moisture, temperature, wind, sunlight and soil. The balance of these factors determine which living things can survive in a particular environment.
What is the difference between Producers and consumers? Autotrophs and heterotrophs?
- Producers/Autotrophs-organisms that get their energy from nonliving resources, meaning they make their own food.
- Consumers/Heterotrophs-organisms that get their energy by eating other living or once-living resources such as plants and animals.
Describe what food webs and food chains are.
Be sure to know the different trophic levels.
- Food Chain-model that links organisms by their feeding relationships.PG408
- Food Web-model that shows the complex network of feeding relationships within an ecosystem.
- Trophic levels-energy flows from lowest to highest level
- Primary Consumers are herbivores because they are the first consumer above the producer trophic level.
- Secondary Consumers are carnivores that eat herbivores
- Tertiary Consumers are carnivores that eat secondary consumers
- Omnivores-such as humans that eat both plants and animals may be listed at different trophic levels in different food chains.
What is the difference between a habitat and a niche?
- Habitat-combined biotic and abiotic factors found in the area where an organism lives.
- Niche-composed of all the physical, chemical, and biological factors that a species needs to survive, stay healthy and reproduce.
Explain the types of symbiotic relationships Ref: difference between a habitat and a niche?
3 symbiotic relationships:
- Mutualism-a interspecies interaction in which both organisms benefit from one another. Ex:Bat transfers pollen from cactus flower to cactus flower that later produce fruit for the bat.
- Commensalism-a relationship between two organisms in which one receives an ecological benefit from another, while the other neither benefits or is harmed. Ex-mites that feed on the secretions and dead skin cells of your body.
- Parasitism-similar to predation in that one organism benefits while the other is harmed. But the parasite benefits by keeping the host alive for days or years. Ex-wasp lays eggs inside a caterpillar. They hatch and eat the caterpillar from the inside out.
Describe succession.
Succession-sequence of biotic changes that regenerate a damaged community or start a community in a previously uninhabited area.
What is a pioneer species?
Pioneer Species-organism that is the first to live in a previously uninhabited area.
How are males, females, genotypes, and phenotypes expressed?
- Males expressed-boxes
- Females expressed-circles
- Genotypes-half shaded
- Phenotypes-completely shaded
What is a pedigree chart?
Pedigree chart-chart for tracing genes in a family.
Describe some of the complex ways alleles are expressed through inheritance.
- Incomplete dominance
- Co-dominance
- polygenic trait
- Epistasis
Incomplete dominance?
a heterozygous phenotype is somewhere between two homozygous phenotypes. Neither allele is completely dominant nor completely recessive. Ex: cross a rd and white flower and get a pink one.
Co-dominance?
both alleles of a gene are expressed completely. Neither allele is dominant nor recessive. Both traits are fully and separately expressed. Ex; Cross a red and white flower and the offspring flower will have red areas and white areas.
