73 terms

Biology Final Exam Review Guide

What is the central dogma of molecular biology and why is it important?
Replication, copies DNA
Transcription converts a DNA message into an intermediate molecule, called RNA
Translation interprets an RNA message into a string of amino acids, called a polypeptide. Either a single polypeptide or many polypeptides working together make up a protein.
This is important because it shows how information flows throughout the cell.
What is a mutation?
A mutation is a change in an organisms DNA.
What is a purpose of a DNA fingerprint?
A DNA fingerprint is a representation of parts of an individuals DNA that can be used to identify a person at the molecular level.
What is a clone?
A clone is a genetically identical copy of a gene or of an organism.
What does genetic engineering mean?
Genetic engineering is the changing of an organisms to give the organism new traits.
Construct and complete a Punnett Square.
Eye Color B b
b Bb bb
b Bb bb
What is the difference between an adaption and a variation?
A variation is the difference in the physical traits of an individual from those of other individuals in the group to which it belongs.
An adaptation is a feature that allows an organism to better survive in its environment.
What is a fossil, and how does is support the theory of evolution?
Fossils are traces of organisms that existed in the past. Fossils support the theory of evolution because they show different but related organisms were alive at different times.
How are sexual and asexual reproductions different?What are the advantages/disadvantages of each?
Sexual reproduction involves the joining of two specialized cells called gametes, one from each of two parents. The offspring that result are genetically unique; they have a mixture of genes from both parents.
-requires two parents and only about half of the offspring can reproduce.
-genetic variation allows a species to survive or possibly thrive in changing or different environments.
Asexual reproduction is the creation of offspring from a single parent and does not involve the joining of gametes. The offspring that result, for the most part, genetically identical to each other and to the single parent.
- more efficient in relatively unchanging environments than sexual reproduction.
-requires only one parent organism, and all of its offspring can reproduce.
-In a changing environment, their genetic uniformity can lead to problems if the environment drastically changes.
What is natural selection?
Natural selection is a mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals. It occurs in four steps. Genetic variation, over production, struggle to survive and differential reproduction. Only the ones that are best fit for their environment survive.
Explain the difference between homologous and vestigial structures
Homologous structures are features that are similar in structure but appear in different organisms and have different functions.
Vestigial structures are remnants of organs or structures that had a function in an early ancestor.
What did Darwin observe on the Galapagos islands that led him to the theory of evolution?
Darwin observed local adaptation. He observed this in the finches which have widely varying beaks based upon what they ate.
What is the difference between natural and artificial selection?
Artificial selection is the process by which humans change a species by breeding it for certain traits. Natural selection is a mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals.
What are the four main principles to the theory of natural selection?
1. Genetic variation
2. Overproduction
3. Struggle to survive
4. Differential reproduction (descent with modification)
Define fitness.
Fitness is a measure of the ability to survive and produce more offspring relative to other members of the population in a given environment.
What is a vestigial structure and how does it support evolution?
Vestigial structures are remnants of organs or structures that had a function in an early ancestor. They support evolution because they show that the organism had a previous evolutionary ancestor that needed the structure to survive.
What is gene pool?
A gene pool is the combined alleles of all of the individuals in a population.
What is allele frequency?
An allele frequency is a measure of how common a certain allele is in the population.
What are the two sources of genetic variation?
Mutations and recombination
What is a normal distribution curve?
A normal distribution curve is a type of distribution in which the frequency is highest near the mean value and decreases toward each extreme end of the range. When this is graphed, it results in a normal bell curve.
What are the three ways a trait can be changed by natrural selection.
1. Directional selection
2. Stabilizing selection
3. Disruptive selection
Explain the bottleneck and founder effect.
The bottleneck effect is genetic drift that occurs after an event greatly reduces the size of a population. The founder effect is genetic drift that occurs after a small number of individuals colonize a new area.
Explain dominant and recessive.
Dominant - An allele that is expressed when two different allele are present in an organisms genotype. It will mask or cover up a recessive allele.
Recessive - An allele that is not expressed unless two copies are present in an organisms genotype.
What are relative and radiometric datings?
Relative dating estimates the time during which an organism lived by comparing the placement of fossils of that organism with the placement of fossils and other layers of rock.
Radoimetric dating is a technique that uses the natural decay rate of unstable isotopes found in materials in order to calculate the age of that material.
Explain the Geological Time Scale.
The geological time scale is a representation of the history of earth. It organizes earth's history by major changes or events that have occurred using evidence from the fossil and geologic records.
What is ecology?
Ecology is the study of the interactions among living things, and between living things and their surroundings.
Explain the five levels of organization in ecology.
Biome - A biome is a major regional or global community of organisms.
Ecosystem - An ecosystem includes all of the organisms as well as the climate, soil, water, rocks and other non-living things in a given area.
Community - A community is a group of different species that live together in one area.
Population - A population is a group of the same species that lives in one area.
Organism - An organism is an individual living thing.
What is the difference between biotic and abiotic factors?
Biotic factors are living things such as plants, animals, fungi and bacteria. Each organism plays a particular role in the ecosystem.
Abiotic factors are nonliving things such as moisture, temperature, wind, sunlight and soil. The balance of these factors determines which living things can survive in a particular environment.
What is a keystone species?
A keystone species is a species that has an unusually large effect on its ecosystem.
What is an autotroph?
Autotrophs are organisms that get their energy from non-living resources, meaning they make their own food
What is a heterotroph?
Heterotrophs are organisms that get their energy by eating other living or once living resources, such as plants and animals.
What is chemosynthesis?
Chemosynthesis is the process by which an organism forms carbohydrates using chemicals rather than light as an energy source.
What is the difference between a food chain and a food web?
A food chain is a sequence that links species by their feeding relationships.
A food web is a model that shows the complex network of feeding relationships and the flow of energy within and sometimes beyond an ecosystem.
What is an herbivore?
Herbivores are organisms that eat only plants.
What is a carnivore?
Carnivores are organisms that eat only animals.
What is an omnivore?
Omnivores are organisms that eat both plants and animals.
What is the difference between a detritivore and decomposer?
Detritivores are organisms that eat detritus or dead organic matter.
Decomposeres are detritovores that break down organic matter into simpler compounds
What does a specialist eat?
A specialist is a consumer that primarily eats one specific organism or feeds on a very small number of organisms.
What does a generalist eat?
Generalists are consumers that have a varying diet.
What do trophic levels try to explain?
Trophic levels shows how energy flows up the food chain from the lowest trophic levil to the highest level.
Explain the steps of the water cycle.
1. Precipitation: water falls from the sky in many forms.
2. Seepage: Water seeps into the ground into streams, waterways, and rivers.
3. Surface water does something similar.
4. Evaporation & Transpiration: Water turns into a gaseous form from liquid or solid forms
5: Condensation: Water vapor condenses into clouds.
Explain the steps of the carbon cycle.
1: Plants photosynthesize and turn CO2 into oxygen and sugars
2: Animals turn the sugars and oxygen into CO2 and H2O
3: As animals die, they decompose into fossil fuels
4: These can be burned and turned into energy and CO2
Explain the steps of the nitrogen cycle.
1: Nitrogen-fixing Bacteria turn atmospheric nitrogen into ammonia (NH3), this can also happen when decomposers break down deceased organisms into ammonium through the process of ammonification.
2: Nitrifying bacteria turn ammonium into nitrites.
3: Nitrifying bacteria then turn the nitrites into nitrates
4: Dentrifying bacteria turn the nitrates into atmospheric nitrogen
Explain the steps of the phosphorus cycle.
1: Phosphate is released when weathering wears down rocks
2: The Phosphate can then either seep into the soil or end up in the water
3a: Phosphate that ends up in the water will form new rocks through sedimentation.
3b: Phosphate that has ended up in the soil can either leech out into the water or be absorbed by plants.
4a: Geologic uplifting then lifts the rocks up to an area where they can be weathered away where it will once again release phosphate
4b: Animals eat the plants, and take in the phosphate
5: When the animals die, decomposers take in the phosphate, and release back into the soil when they die
What is binomial nomenclature?
Binomial Nomenclature is a system that gives each species a two part scientific name using Latin words. The first part of the name is the genus. The second part of the name is the species descriptor.
What is taxonomy?
Taxonomy is the science of naming and classifying organisms.
What is the genus of a barn owl?
What is the species of a barn owl?
What are the three domains?
Bacteria, Archaea, Eukarya
What are the taxonomic levels of living things(KPCOFGS)?
Kingdom, Phylum, Class, Order, Family, Genus, Species
What are the limitations to the Linnaean system?
The limitations to the Linnaean system are that it does not allow for classification at the molecular level. Also, it relies completely on physical similarities but unrelated species can evolve similar traits through convergent evolution.
What is the difference between a genus and a species?
A genus includes one or more physically similar that are thought to be closely related. While a species is only one organism.
What is a habitat?
A habitat can be described as all of the biotic and abiotic factors in the area where an organism lives.
What is a competition?
Competition occurs when two organisms fight for the same limited resources.
What is predation?
Predation is the process by which one organism captures and feeds upon another organism.
What is symbiosis?
Symbiosis is a close ecological relationship between two or more organisms of different species that live in direct contact with one another.
What are the three kinds of symbiotic relationships?
Mutualism, Commensalism, Parasitism
What is the difference between an endoparasite and an ectoparasite?
Ectoparasites make their home on the exterior of an organize by attaching itself to the outside of the host and usually feeding on its fluids. Endoparasites live in the tissues and organs of a host where, safely hidden, they feed on the nutrients ingested by their hosts.
What is population density?
Population density is a measurement of the number of individuals living in a defined space.
What is a limiting factor for a population?
The factor that has the greatest effect in keeping down the size of a population is called the limiting factor.
What is the difference between density-dependent and density-independent factors?
Density-dependent limiting factors are limiting factors that are affected by the number of individuals in a given area.
Density-independent limiting factors are the aspects of the environment that limit a population's growth regardless of the density of the population.
What is a pedigree?
A pedigree chart can help trace the phenotypes and genotypes in a family to determine whether people carry recessive alleles.
Explain how a pedigree can be used?
A pedigree can be used to trace genes, genotypes and phenotypes in a family to determine whether people carry recessive alleles.
What is a karyotype?
A karyotype is a picture of all of the chromosomes in a cell.
What is the shape of DNA called?
Double Helix
What are the base-pairing rules of DNA?
Thymine(T) always pairs with adenine(A)
Cytosine(C) always pairs with guanine(G)
What are the three differences between RNA and DNA?
1. The sugar in RNA is ribose instead of deoxyribose, which has an extra oxygen atom.
2. RNA has the base uracil in place in thymine.
3. RNA is a single strand of nucleotides in contrast to the double stranded structure of DNA.
Name and describe the six biomes. (Tropical)
Tropical - Tropical rain forest
*Warm temperatures and abundant rainfall occur all year.
*Vegetation includes lush thick forests.
*Animals that live within the thick cover of the uppermost branches of rain forest trees use loud vocalizations to defend their territory and attract mates.
Name and describe the six biomes. (Grassland)
Grassland - Tropical Grassland
*Temperatures are warm throughout the year, with definite dry and rainy seasons.
*Hoofed animals, such as gazelles and other herbivores, dominate this biome.

Temperate grassland
*This biome is dry and warm during the summer, most precipitation falls as snow during the winter.
*Vegetation includes short or tall grasses, depending on the amount of precipitation.
*Many animals live below ground to survive the dry and windy conditions in this biome.
Name and describe the six biomes. (Desert)
*This biome has a very dry climate.
*Plants, such as cacti, store water or have deep root systems.
*Many animals are nocturnal; they limit their activities during the day.
Name and describe the six biomes. (Temperate)
Temperate - Temperate deciduous forest
*Temperatures are hot in the summer and cost in the winter; precipitation is spaced evenly over the year.
*Broadleaf forest dominates this biome, and the deciduous trees lose their leaves in the winter.

Temperate rain forest
*This biome has one long wet season and a relatively dry summer.
*Evergreen conifers, which retain their leaves (needles) year-round, dominates this biome.
*While some species remain active in the winter, others migrate to warmer climates or hibernate
Name and describe the six biomes. (Taiga)
*This biome has long, cold winters and short, warm humid summers.
*Coniferous trees dominate this biome.
*Mammals have heavy fur coats to withstand the cold winters.
Name and describe the six biomes. (Tundra)
*Subzero temperatures are the norm during the long winter, and there is little precipitation.
*The ground is permanently frozen; only mosses and other low-lying plants survive.
*Animal diversity is low.