Review for Final Biology Exam
(Please note: some of the definitions were copied directly from the Modern Biology textbook, some were copied from Microsoft Office “All Reference Books,” and some were copied from http://www.emc.maricopa.edu/faculty/farabee/biobk/BioBookgloss.html, http://www.kidsgardening.com/onlinecourse/glossary.htm, http://www.answers.com/topic/multiple-allele, http://www.phschool.com/science/biology_place/glossary/g.html, http://www.angelfire.com/ks3/jcfriesen/Plantae.html, )
Genetics
· Gregor Mendel – father of genetics (1830s.) Originally he was a monk working in a garden and he decided to experiment crossing different pea plants. By doing these experiments he eventually came up with the principles of heredity.
· Heredity – the transmission of traits from parents to their offspring
§ Trait – in genetics, a category within which alternate characteristics, such as height and eye color, can be observed
§ Progeny – children/ offspring
· Genes – A segment of DNA that contains coding for a polypeptide or protein; a unit of hereditary material
§ Allele - one of two or more alternative forms of a gene, occupying the same position (locus) on paired chromosomes and controlling the same inherited characteristic.
· One kind of allele (dominant) masks the other kind of allele (recessive.) 2 kinds of alleles have three possible combinations
~ Dominant allele is represented by a capital letter
~ Recessive allele is represented by a lower case letter
~ True breeders will have same case letters; non-true breeders will have each cased letter
· Multiple alleles - Any of a set of three or more alleles, or alternative states of a gene, only two of which can be present in a diploid organism.
§ Homozygous – referring to a gene pair in which the two alleles code for the same trait
§ Heterozygous – referring to a gene pair in which the two alleles do not code for the same trait
§ Law of independent assortment – each pair of alleles separates independently giving new genetic combinations
§ Incomplete dominance – two dominant (homozygous) genes, when crossed together the result is a combination of traits (ex. pink when red and white are crossed)
§ Law of segregation – (1840’s-1850’s) two alleles separate gamete formation
· Chromosome -DNA and protein in a coiled, rod-shaped form that occurs during cell-division; these structures in the nucleus of a eukaryotic cell contain the genes of the organism
§ Autosome – a chromosome that is not a sex chromosome (in humans there are 22 autosomal chromosomes)
§ Sex chromosome – a chromosome that determines the gender of the organism
§ Gametes – reproductive cells
· Zygote – the diploid cell that results in the fusion of gametes (2n).
· Diploid – a cell that contains both chromosomes of a homologous pair (2n)
· Haploid – having only one chromosome of each homologous pair (n)
· Sex linkage - The condition in which the inheritance of a sex chromosome is coupled with that of a given gene; e.g., red-green colorblindness and hemophilia in humans. Traits located on the X-chromosome only (the X-chromosome is the carrier of the trait), not on the Y-chromosome.
§ Hemophilia – a trait in which the blood lacks a protein that is essential for clotting, this is a recessive X-linked gene that mostly occurs in males
§ Colorblindness – recessive X-linked disorder which causes a person to be unable to distinguish between certain colors, this mostly occurs in men
· Punnett square – a model used to establish the probabilities of the results of a genetic cross (you should know how to make a Punett square and how to read it)
§ F1 generation – the offspring of cross pollinated P generation plants
§ Probability – the number of times an event is expected to happen divided by the number of opportunities for an event to happen.
§ F2 generation – the offspring of self pollinated F1 generation plants
§ Monohybrid cross – a cross between individuals that involves one pair of contrasting traits (ex. PP x pp, or PP x Pp, etc…)
§ Dihybrid cross - a cross between individuals that involves the pairing of contrasting traits. In other words you are crossing two pairs of alleles at the same time.
· Genotype – the genetic makeup of an organism
· Phenotype – the visible characteristics of an organism resulting from the interaction between its genetic makeup and the environment
Evolution
· Evolution – the theory that living things change over time.
· Darwin was interested in biology; he traveled around the world in a ship collecting different species of organisms. (He wrote “The Origins of Species”)
§ Artificial selection – people can cause changes in different species over time (by breeding specific species with others)
§ Malthus compared birth and death rates in England and America. In England population was staying the same, America’s population was growing. Population size grows much faster than food supply
§ Sexual Selection: the key is finding a mate rather then surviving
§ Darwin’s ideas are widely accepted today
· Wallace and Darwin didn’t know each other but discovered, wrote, and publicized the same ideas around the same times
· Natural selection “the better competitors are better at staying alive, and they have a better chance of reproducing” this theory was credited to both Darwin and Wallace
§ Many more individuals are born in each generation than will survive and reproduce – statement first introduced by Malthus
· Evolutionary fitness – having lots of offspring
§ There is variation among individuals; they are not identical in all their characteristics
§ Individuals with certain characteristics have a better chance of surviving than individuals with other characteristics (some variations are favorable for survival and some are unfavorable
§ Some of the characteristics resulting in differential survival and reproduction are heritable
§ favorable variations will increase slightly in each generation
§ vast spans of time have been available for change
· Biogenesis
§ The principle that living organisms develop only from other living organisms and not from nonliving matter.
§ Generation of living organisms from other living organisms.
§ The supposed recurrence of the evolutionary stages of a species during the embryonic development and differentiation of a member of that species
· Vestigial structure: evolutionary leftover; having become degenerate or functionless in the course of time
· Bell Shaped Curve: graph that shows change of a certain characteristic in different generations
§ If you breed individuals with the same characteristics breed together then after a while you will have more individuals with that characteristic then those without it.
§ The way that giraffes have long necks is because they needed food so those with longer necks survived longer than the others and these mated together giving birth to children with even longer necks…
· Lamarck
§ Body parts change during organisms life due to use or disuse – acquired characteristic
§ These changes are passed down to the next generation – this isn’t necessarily true
· Divergent evolution – many different forms evolving from a single form (adaptive radiation)
§ This leads to homologous structure: have a common ancestor but are different in form and function
· Convergent evolution – unrelated forms evolve to resemble each other (development of similar appearance, structures, or behavior on unrelated species or populations by similar selection pressure)
§ Analogous structure evolution: have similar form and function but have evolved independently (from different ancestors)
Classification and Phylogeny
· Carl Linnaeus was a Swedish scientist who laid foundation for modern taxonomy.
§ Taxonomy is the naming and classifying of living things
· Classification and Phylogeny (Phylogeny: evolutionary relationships)
§ Binomial nomenclature: two word naming system à Genus species
· Genus: noun, capitalized, underlined or italicized
· Species: descriptive, lower case, underlined or italicized
§ Hierarchal Classification
· Taxonomic categories: KingdomàPhylumàClassàOrderàFamilyàGenusàSpecies
§ Systematic: Evolutionary Classification
· There are Six Kingdoms
§ Eubacteria (Domain: bacteria)
§ Archaebacteria (Domain: Archaea – live in extreme conditions)
§ Protista (Domain: Eukarya)
§ Plantae (Domain: Eukarya)
§ Fungi (Domain: Eukarya)
§ Animalia (Domain: Eukarya)
Ecology
· Ecosystem: all the living and nonliving things in a given area
· Community: all the living things in a given area
· Population: all the members of one species in a given area
· Biosphere: parts of earth where life is found
Habitat / NicheWhere an organism lives / Everything an organism needs to survive
Producersàconvert light energy into food energy / Consumers
Autotrophs / Heterotrophs
· Everything in the world is either energy or matter
§ Energy: flow through ecosystem – energy comes from light and exits as heat
§ Producers (autotrophs) make light energy into food energy through photosynthesis used by the consumers (heterotrophs)
§ Net productivity - The rate at which producer (usually plants) biomass is created in a community.
§ Gross productivity - A measure of the rate at which energy is assimilated by the organisms in a trophic level, a community, or an ecosystem.
· Food chain – a pathway of food through the ecosystem
§ Producers (terrestrial - food; marine - phytoplanton) à primary consumers (terrestrial - herbivores; marine - zooplankton) à secondary consumer (carnivores) à tertiary consumers à quaternary (carnivores)
- Herbivores – plant eater (ex. cattle)
- Carnivores – meat eater (ex. lions)
- Omnivores – eat both (humans and bears)
- Biotic Factor – living component of an ecosystem
- Abiotic Factor – any non-living component of an ecosystem
- Logistic Growth - A model of population growth in which the population initially grows at an exponential rate until it is limited by some factor; then, the population enters a slower growth phase and eventually stabilizes.
§ As you go along the food chain the amount of energy decreases (it goes down by the power of 10)
§ Food web – one can use the web in order to identify the trophic level of a certain organism
§ Food pyramid - A way of depicting energy flow in an ecosystem; shows producers (mostly plants or other phototrophs) on the first level and consumers on the higher levels.
§ Productivity – amount of food made per given area per year
§ Detritus: non-living organic material (1) dead bodies (2) feces
- This is eaten by detritovores
§ Decomposers – break down any organic matter not broken down by consumers (usually the decomposers are the bacteria)
§ Biomass – weight of living tissue
§ Biological magnification – concentration of a poison increases (by the power of 10) as you go up each trophic level
Matter recycles Carbon Cycle
energy flow
Nitrogen cycle
Ecosystems
· Climate – temperature, and precipitation
· Biome – major ecosystem
§ Biome: Tropical Rain Forest
· This is the most productive biome. It’s producers are trees
· Canopy – leaves of rain forest trees completely shade rain forest ground
· Vines in this ecosystem grow quickly – they wrap around the trees to get to the top thus contributing to the canopy.
· Epiphytes grow on top of other plants (they have no ground roots.)
· There is a very high diversity of species in the rainforest. The soil there is very poor because the organic material recycling takes place very quickly. The soil underneath the trees is very dry to such an extent that it becomes clay do to the lack of water.
· Arboreal – animals that live in the trees
§ Biome: Temperate Deciduous Forest
· Temperate – mild, having different seasons; deciduous – they lose and grow leaves depending on season
§ Biome: Boreal forest
· The great northern forest – taiga. Producers of this biome are conifers – it is a coniferous forest
§ Biome: Tundra
· Climate: winters are very long and summers are very short. This makes the ground permanently frozen – permafrost. Some low lying plants grow there: mosses and lichen.
- Lichens are composed of two parts: alga which produce the food and fungi which provide protection. During the short summers the place is soggy because the top layer melts but the water can’t absorb. There are parts of the globe where nothing at all grows due to the immense cold.
§ Biome: Grassland
· The producers of this biome are grass; the consumers are large hoofed animals. In these places there is little rainfall, the secondary consumers are wild animals (such as lions, tigers, cheetahs, etc...)
§ Biome: Desert
· This is the driest biome it gets under 10” of rain per year. The producers of this biome are plants that are adaptive to little rainfall (ex. Cacti.) The rainy season in this biome is very short so the plants reproduce and do their other important activities (such as gather water and photosynthesize.) The rest of the time (during the dry season) they are dormant. Consumers in this biome are animals that also are capable of adapting to the very dry conditions (such as camels.) Deserts have wide diurnal (daily) fluctuation. Therefore the animals are nocturnal. An example of this biome is the savanna desert.
Species interactions
· Predation: predator à prey (relationship between predator and prey)
· Competition: the niche of two species overlaps (competing for the same things)
§ Competitive exclusion – no two species can occupy the same niche.
§ There was an experiment where two paramecium were put in a jar and given the same amount of food all times; the result was competition and in the end one survived the other didn’t.
· Symbiosis: living together
User / UsedCommensalisms / J -benefits / K - neutral
Mutualism / J - benefits / J - benefits
Parasitism / J - benefits (parasite) / L - harmed (host)
· There are many ways to avoid being eaten for example: mimicry and camouflage
· Succession – fist there are species (pioneer species who colonize an area) they can withstand the harsh conditions of the place and by colonizing there they improve the condition. Then a new species of plants come in which are better competitors then the pioneer species so they take over the place and improve it more. This last step happens many times until finally a very strong species comes in called the climax community which is very stable; the only way to destroy a climax community is by a disaster such as a forest fire.