The purpose of a streak plate is to produce colonies of a certain organism. These colonies are formed by encouraging the growth of only one organism, which allows the separation of that organism from a sample containing multiple organisms.
A streak plate is prepared with nutrients that are specifically chosen to support the growth of the desired organism. It may also contain chemicals that are toxic to other organisms. These chemicals will kill any organisms that might contaminate the organism you want to study. This combination should result in a plate of isolated colonies of a desired organism.
As well as isolating chosen organisms, streak plates may also be used to support more investigative study of a particular organism. The nutrients in a streak plate can be manipulated to study their effects on the organism, and by setting up different combinations, the effects of changes to the organism's environment can be tested.
A streak plate can also be used to study an organism's normal morphology and lifecycle. In this case, a streak plate can provide an organism with the ideal ratio and amount of nutrients for optimum reproduction and keep any toxic chemicals from reaching the colony. This permits the study of the organism without contamination or interference from any outside factors.Learn More
The organelles that contain digestive enzymes are called lysosomes. These cellular structures primarily function for the breakdown of complex molecular substances, such as carbohydrates, lipids, proteins and nucleic acids.Full Answer >
Nucleotides are the monomer of DNA. They are made of a 5-carbon sugar (deoxyribose), a phosphate group, and a nitrogenous base bound to the sugar. The four different types of nucleotides are adenine (A), thymine (T), guanine (G) and cytosine (C).Full Answer >
Speciation, commonly known as macroevolution, is supported by several lines of evidence, including direct observation, genetic mapping and the fossil record. Several populations have been observed in the act of splitting into new species. Comparison of genomic sequences between species are most easily explained as a result of recent common ancestry and an extensive fossil record has yielded numerous transitional fossils.Full Answer >
Genetic variation is important to evolution because it helps to maintain the health of a population by constituting alleles that may be useful in overcoming stresses such as diseases and pests. Without genetic variation, some of the fundamental mechanisms of evolutionary changes would not operate.Full Answer >