Essential Biology Assignment 08
Discuss the applications of each of following in biology today and include three examples of each with a brief description.
- DNA in forensic science
- Population evolution and microbial life
- Biological diversity evolution
- Plant and animal evolution
- Population growth
- Biomes and ecosystems
Essential Biology Assignment 08
DNA in Forensic Science
Forensic scientists today have become indispensable in the sector of solving crimes especially with the advanced technology that is available today. Forensics is a combination of criminal justice and advanced science where researchers can take samples of blood or hair from a crime scene for further lab analysis. All genetic information of an organism is contained in the molecule known as DNA (Sax, Stachowicz, & Gaines, 2005). A human genome consist of more than just the gene (DNA regions that are responsible for encoding and regulating protein synthesis). The larger part of the genome is of particular interest to forensic scientists since it is made up of extragenic DNA that contains regions of unknown gene sequences. In particular, the repetitive DNA is used in forensic analysis and it makes up roughly 50% of extragenic DNA. The repetitive DNA is further broken down into tandem and interspersed repeats:
repeats- minisatellites and microsatellites
- Interspersed repeats- LINE, LTR, SINE and Transposon
The variation between tandem repeat DNA is referred to as polymorphism and is the primary focus of a majority of profiling techniques. The location and number of these polymorphisms are unique to every person and hence forensic analysts use it to provide undeniable proof (Sax, Stachowicz, & Gaines, 2005).
DNA samples can be obtained from some sources including; vaginal fluid, semen, blood, hair, blood and nasal secretions among others.
- Blood from a crime scene could be swabbed for further analysis in the lab.
- A cigarette butt could also give evidence if analyzed for saliva samples.
- A condom or underwear could be used to analyze the sexual secretions for DNA.
Population Evolution and Microbial Life
Microbial population biology is the use of population genetics and ecology in trying to understand the evolution of bacteria, viruses, fungi and eukaryotes. A population refers to a group of individuals known as species (since they can interbreed). The genes contained by these species are passed on from one generation to the next and are collectively referred to as a gene pool. Evolution cannot occur in individuals per se but only in populations (Sax, Stachowicz, & Gaines, 2005). Genetic evolution in a species can come about as a result of the following; mutation, natural selection, gene hitchhiking
Microbes are microscopic, and most are unicellular and hence are neither plants nor animals. The diversity and a sheer number of bacteria are way higher than that of macroscopic life both on land and in oceans. These microscopic organisms display unique mechanisms to survive:
- The HIV has evolved over time and has grown some resistance towards certain antiretroviral medication
- Microbes are also chemosynthetic, relying on chemical processes to drive their metabolism. Acidobacteria can exist in highly acidic soils by pumping out protons to maintain neutral pH in their intracellular environment.
- Some microbes prey on others while consuming hydrocarbons and other toxic waste. The Deinococcus and Thermus bacteria also display unique mechanisms for survival. Deinococcus consumes nuclear waste and can survive in a vacuum while the Thermus bacteria is resistant to heat (Sax, Stachowicz, & Gaines, 2005).
Biological Diversity Evolution
Biological diversity evolution is simply the processes that generate and maintain the variations in species. Some areas are known as biodiversity hotspots since they are small but contain an enormous number of species. The hotspot is determined by some species (including endemic) and the degree of the threat of extinction (“Campbell Essential Biology, 5e – Open Access”, 2016). Evolution and biodiversity mainly cover evolutionary processes, patterns of species and their evolutionary relationships. Evolution of biodiversity is evident in the provision of raw materials for the production of food and medicine.
- Genetic biodiversity- it only refers to the gene variation that exists within any particular species. Many individuals of a given species may die during winter due to the cold. If the entire population has a genetic diversity that allows for fat storage, it allows for heat insulations and hence future generations will survive.
- Ecological diversity- it involves the variety of available habitats in any given location. These habitats may display differences in aspects such as temperature, climate, soil type or even the organisms that inhabit them. Six species of baobab are endemic to Madagascar alone as well as the Cymbidiella orchid which is endemic (“Campbell Essential Biology, 5e – Open Access”, 2016).
- Taxonomic diversity- refers to the variety of organisms in a particular hierarchical level in the binomial nomenclature. A rice field may contain many birds, but all of them represent only three species found in one family. In such a case, the taxonomic diversity is low and vice versa.
Plant and Animal Evolution
Evolution involves the change in populations, not individuals, over time. Living things tend to change as time goes by as a result of influences found in their natural habitat to ensure survival. Events such as climate change have shown why plants and animals must evolve or risk extinction (“Campbell Essential Biology, 5e – Open Access”, 2016).
- Peppered moth- originally, it was light and mottled in color to protect from predators. The industrial revolution came with a lot of pollution and hence the insect evolved into a dark colouration to be camouflaged from predators in the now darkened atmosphere.
- The cane toad is an invasive species that is highly destructive to agriculture. The toads invade a region and those at the front tend to be the fastest and strongest of them. The first frogs mate amongst themselves to produce a species that is stronger and quicker and hence the invasions will worsen.
- Continental drift caused plates to shift and hence similar vegetation can be found in different places on earth. Plants like cacti and Euphorbia have evolved to survive desert conditions. They are different plants, but both have succulent stems and tiny leaves or spikes to preserve water (Sax, Stachowicz, & Gaines, 2005).
In ecology, growth refers to a change in numbers and can be either positive or negative. Positive growth implies an increase in growth and negative growth implies a decrease the opposite. Zero growth suggests that the population remained the same. Exponential growth is not possible since the resources available are limited. Logistic growth is when population increases until the available resources cannot sustain a further increase (the carrying capacity is achieved) (“Campbell Essential Biology, 5e – Open Access”, 2016).
Yeast shows perfect logistic growth when grown in a test tube. The growth tops off when the yeast consumes all the available nutrients necessary for its survival.
Biomes and Ecosystems
An ecosystem consists of all living and non-living things in any environment and their interaction with each other. A biome, on the other hand, is a particular geographical location recognized for the type of species that live there. Biomes are defined by abiotic factors such as climate, geology, relief, soils and vegetation (“Campbell Essential Biology, 5e – Open Access”, 2016). Plants and animals that exist in a certain biome will display specialized adaptations that enable them to survive within the area. Several ecosystems can be found in one biome. There are several biomes within which exist well-defined eco-systems:
biome- hot and dry regions including cold deserts.
- Aquatic biomes- include freshwater and marine biomes
- Forest biomes- consists of tropical rainforests, temperate forests, and boreal forests.
- Grassland biomes- savannah and temperate grasslands
- Tundra biomes- arctic and alpine tundra
Campbell Essential Biology, 5e – Open Access. (2016). Wps.aw.com. Retrieved 24 October 2016, from http://wps.aw.com/bc_campbell_essentials_5_oa/220/56555/14478088.cw/-/t/index.html
Sax, D., Stachowicz, J., & Gaines, S. (2005). Species invasions. Sunderland, Mass.: Sinauer Associates.