Final Review Flashcards
Identify and explain the six characteristics of living things.
- Cells- all living things are composed of cells
- Organization- living things are organized at both the molecular and cellular levels
- Energy use- all living things use energy in a process called metabolism
- Homeostasis- organisms have systems for maintaining their internal environment
- Growth- grow as a result of cell division and enlargement
- Reproduction- not essential for organisms survival, but it is essential for species continuation.
Explain whether both yeast and viruses are living things.
Yeast- yes it is living. Like all living things it needs energy to be active, which it gets in the form of sugar. It then releases CO2.
Viruses- No, because they cannot reproduce outside of a host cell and do not use the typical cell divisionapproach to replication.
Understand the scientific methid, including the three different types of controls used in experiments.
The Scientific Method
1) observe
2) ask a question
3) collect data
4) hypothesize
5) experiment + analyze
6) draw a conclusion
Controls
1) Control- factors that remain the same (water)
2) Independent- factors that differ (sugar)
3) Dependent- Driven by the result of the independent variable (yeast)
Summarize Redi’s experiment.
He questioned the belief that flies came from rotting mean.
Experimental Goup- netting covered jars that contained meat.
Control Group- uncovered jars that contained meat
Result- after a few days, maggots swarmed over the meat in the open jar while the covered jars had no maggots, meaning flies came only from eggs laid by other flies.
Summarize Spallanzani’s experiment.
He was testing the spontaneous generation of microorganisms.
Experimental Group- boiled clear, fresh broth until flasks filled with steam. Sealed flasks by melting the opening closed.
Control Group- flasks of boiled broth that were left open.
Results- broth in sealed flasks remained clear while broth in open flasks became cloudy with microorganisms. He concluded that boiled broth became contaminated only when air entered the flasks.
Summarize Pasteur’s experiment.
He made a curved neck flask that allowed air inside the flask to mix with air outside the flask. curve prevented microorganisms from entering the flask. Broth inside remained clear for a year, but when he broke off the neck the flask became cloudy. He reasoned that it was due to microorganisms in the air.
Explain Oparin’s hypothesis in relation to the synthesis of the first organic compounds on Earth.
Oparin thought that the early atmosphere of Earth was very different. He thought the early atmosphere contained ammonia, hydrogen gas, and methane. Oparin believed that when the Earth cooled and lakes and seas formed, these organic compounds collected in water. Over time, these entered chemical reactions fueled by lightening which resulted in macromolecules.
Summarize Miller and Stanley’s experiment that tested Oparin’s hypothesis.
They set up an experiment using Oparin’s hypothesis as a starting point. Their apparatus had a chamber containing the gases Oparin assumed were present in Earth’s atmosphere. As the gas circulated, electric sparks (to mimic lightening) supplied energy to drive chemical reactions which resulted in organic compounds, specifically amino acids which are the building blocks of proteins.
Explain the law of superposition using the terms stratum and relative age.
The law of superposition allowed paleontologists to assign relative ages to fossils because they could tell how old they were based on which stratum they were found in.
Explain Lamarck’s theory of evolution using the term acquired traits.
An acquired trait is one that is not determined by genes, but instead arise during an organisms life time as a result of its experience or behavior. Lamarck believed that organisms evolved by passing along acquired traits.
Explain Darwin’s theories of descent with medication and modification by natural selection using the terms adapt, fitness, and adaptive advantage.
Descent with modification- newer forms appearing in the fossil theory are modified descendants of older species.
Natural selection- organisms best suited to their environment reproduce more successfully than other organisms. Over generations, the porportion of organisms with favourable traits increases in a population.
Adapt- a population of organisms adapt to their environment as their porportion of favourable genes increases.
Fitness- an organisms contribution to the next generation. An organism with high fitness will reproduce more successfully than an organism with low fitness.
Adaptive advantage- a favourable trait given to an organism.
Compare Darwin’s theory with Lamarck’s theory.
Darwin’s theory differs from Lamarck’s theory because Lamarck proposed that organisms evolve by inheriting acquired traits and Darwin proposed that organisms evolve as a result of natural selection, meaning that organisms with higher fitness will produce more successfully than those with low fitness who will eventually die out.
Use examples to define homologous features.
Similar features that originated in a shared ancestor. Derived from the same embryological structure of each different species. Ex. Wing and arm.
Use examples to define analogous features.
Serve identical functions and look somewhat alike. They have very different embryological development and may be very different in internal anatomy. Ex. Wings of a bird and wings of a bee.
Define vestigial structure.
Features that were useful to an ancestor but are not useful to the modern organism that has them. Ex. Tailbone, wisdom teeth, and appendix in humans.
Recognize the patterns of evolution such as coevolution, convergent and divergent.
Coevolution- the change of two or more species in close association with each other.
Convergent- when organisms appear to be very similar, but are not closely related at all. Occurs when the environment selects similar phenotypes even when the ancestral types were quite different from each other.
Divergent- Two or more related species or populations become more and more dissimilar. Nearly always a response to differing habitats and can ultimately result in a new species.
Show how adaptive radiation and artificial selection are important types of divergent evolution.
Adaptive radiation- many related species evolve from a single ancestral species.
Artificial selection- the process of divergence is sped up artificially beyond what could normally happen in nature.
Relate convergent and divergent evolution to analogous and homologous features using examples.
Homologous is when two species share a common ancestor, and divergent evolution is when two species become more and more dissimilar (like humans and monkeys).
Analogous is when species don’t evolve from the same ancestor but share features with the same purpose, and convergent evolution is when organisms appear to be very similar but are not closely related at all (like the adult horsefly and mosquito mouth parts).
Population genetics.
The study of evolution from a genetic point of view. A population is the smallest unit in which evolution occurs.
Gene pool.
The set of all genes or genetic formation in any population, usually of a particular species.
Allele.
A variant form of a gene, I.e. For height, the alleles are short and tall.
Genotype
An individual’s collection of genes
Phenotype
An individual’s obsevable trait, such as eye colour, hair colour, etc.
Phenotypic frequency
The number of organisms with a phenotype divided by the total number of a population.
Explain three main ways in which variations can arise.
- Random fusion of gametes- game of chance played by individual gametes.
- Recombination- the reassociation of genes when an offspring receives genetic information from both parents.
- Mutations- mutations result from flawed copies of individual genes.
Summarize the five points of the Hardy-Weinberg Equilibrium.
1) No mutation- allele frequencies do not change overall because of mutation.
2) No migration- Individuals neither enter nor leave the population.
3) The population must be large - not small.
4) Individuals must mate randomly.
5) Natural selection does not occur.
What are the five violations of the Hardy-Weinberg Equilibrium?
Mutation, migration, genetic drift, no random mating (assortative mating), natural selection.
Use examples to describe the three broad types of natural selection0 stabilizing, direction, and disruptive.
Stabilizing- individuals with the average form of a trait have higher fitness. Ex. Babies with normal birth weight.
Directional- Individuals that display a more extremem form of.a trait have better fitness than those that display an average form of the trait. Ex. Tongue length in anteaters, long tongues are better in areas with deep nests.
Disruptive- individuals with either extremem variation of a train have greater fitness than individuals with the average form. Ex. Limpet shells very from white to tan to black. White shelled limpets on white rocks, and dark limpets on dark rocks are at an advantage because birds can’t see them.
