BSC 1005 Latest Upload Midterm Exam 2025

BSC 1005 Latest Upload Midterm Exam 2025 Biodiversity - -the variety of life, and can refer to: habitat, species and genetic diversity, Developmental diversity - -differences in cells within the body Genetic biodiversity - -differences in genes Geographical biodiversity - -differences in life between geographical regions Vast number in species of life - -there are between 1.5 and 2 million named species of living things on earth. Plants-300,000 fungi-100,000 bacteria and protista-100,000 vertebrates-50,000 insects-950,000 Species - -a population or group of populations of organisms that are very similar to one another(share a recent evolutionary history) Important components of species - -the ability to interbreed Lennean system of classification - -binomial names(two names) Genus species - -ex. Homo sapiens(humans)... Homo is the genus name and sapiens is the species Species richness - -the number of species occurring in a particular area Species diversity - -combination of number of species and relative number of individuals of each species Diversity of species throughout the world - -species are not spread evenly throughout the world, ex. Tropical areas typically have more species than temperate ones Ecosystems - -combination of both biotic and abiotic factors Ecosystem services - -something such as oxygen, fresh water, or food that is provided by an ecosystem by its species Genomics - -the new use of the comparative method Genome - -entire set of genetic material in a cell BCS 1005 BCS 1005 Allele - -particular version of a gene Source of genetic variation - -individuals having different alleles Human impact on biodiversity - -is negative due to human interactions such as pollution, agriculture, etc World event taking place due to negative human impact on biodiversity - -going into the world's 6th mass extinction event. Current extinction rates are between 10 and 100 times higher than those estimated from the fossil record Populational thinking - --is a way of looking at the world. Views people, animals, bacteria, cities,etc. As being parts of a population of similar things -individuals are being influenced by many factors so it can be hard to say the cause of something is Typologically - -assigns different things to categories Evolution - -based on the variation with natural selection being the primary mechanism of evolution. Characteristics that help organisms surviveand reproduce will become prevalent in that environment. Three that must take place for evolution to occur - --competition(more born than survive) -inheritance(pass traits to offspring) -variation(individuals all have different traits) Charles darwin - -traveled to the galapagos. This where came up with the idea of evolution/ Darwin's two main ideas - --descent with modification -natural selection Evidence of evolution - --life on islands -homology -fossil record Alfred Wallace - -learned about biodiversity by traveling through the amazon and southeast asia Stabilizing selection - -genetic diversity decreases as the population stabilizes on a particular trait value Disruptive selection - -population tend to diverge into two different groups Directional selection - -common in response to change in environment BCS 1005 Reproductive isolation - -allows for independent evolution Standard deviation - -measure of the amount of variation in a population How are species formed? - -through some sort of geographical isolation Population variation - -can make the link between cause and effect less straightforward ex. Smoking and cancer Ecology - -study of factors influencing the distribution and abundance of organisms Biomes are determined by what factors - --temperature -precipitation -seasonality Seasonality is important because? - -it is important in distinguishing habitats, such as the desert from the Mediterranean Ecological niches - -the ecological role of species and allow organisms to split the environment into different pieces so many species can live within a community Examples of ecological niches - --microclimate -pollution tolerance -food eaten Community - -all the species in an area Parasitoids - -alter the behavior of their hosts 3 main types of species interaction - --predation -competition -mutualism Predation - -includes eating plants, parasites and parasitoids Primary producers - -make own food and carbon through photosynthesis. Food web facts - --only plants can bring energy into an ecosystem -nitrogen fixing bacteria are required to supply ecosystems with nitrogen Disturbances - -influence the number of species within a community and leads to succession An intermediate amount of disturbance= - -high diversity BCS 1005 BCS 1005 BCS 1005 Too little disturbances= - -low diversity: low diversity species become highly specialized and hard for new species to come in Too much disturbances - -low diversity:low diversity. It doesn't allow for species to thrive before it is destroyed again Selective breeding - -humans choose individuals with desirable traits. The smaller sample size leads bigger and more drastic results Selective breeding can lead to... - -a loss of genetic diversity which is a problem due to a long term selection leading to vulnerability to diseases • genetic engineering/modification - -allows much more specific manipulation of genes and is done through the use of viruses Monoculture - -focuses on growing one plants species- low diversity high disturbances, which makes them vulnerable to pests and weeds The body fighting off disease - --the immune system works by attacking non-self organisms Acquired immunity - -the immune system "learns" to attack a specific thing to prevent reinfection by the same disease Types of disease organisms - --virus -bacteria -parasites Virus - -non-living, need a host cell to reproduce, and very difficult to kill because they evolve quickly (ex. Hiv) Bacteria - -- single celled (prokaryote) easier to kill because so different from human cells and can be treated with antibiotics (ex. Malaria) Parasites - -harder to spread between people but harder to kill because they have similar cells Plant and fungal medicines - --taxol-anti cancer agent -digitoxin-heart medication derived from fox glove plant -penicillin-derived from fungus -most natural products of medicine come from tropical rain forests -plant secondary compounds are important source of medicines Peyote - -small, spineless cactus used worldwide as an entheogen (religious or spiritual