1. Samples of a microbial colony obtained from the natural environment are not pure culture. They are mixed cultures because the environment consists of an array of microorganisms and not one specific organism. A sample obtained from the natural environment such as water or soil may contain several species of microbes that need to be further isolated to obtain a pure culture.
2. Isolation streak plate technique involves the dilution of the sample several folds and then streaking a small amount using a sterile inoculation loop on an agar plate in a zig-zag manner. This is done to obtain a pure culture of bacteria from a mixed population by separating the microprocessor. When the sample is diluted into a small concentration and is streaked onto agar placed, widely spaced, discrete colonies of bacteria can be observed. These isolated colonies can be further cultured to obtain pure cultures by picking and re-streaking them on fresh agar plates.
3. A microbial colony is considered a pure culture because it consists of single species. A single species of bacteria cluster and form an isolated colony on an agar plate which can be further plated on fresh medium.
3-1 - If your agar plate shows discrete uncluttered colonies then you have obtained an isolated colony. The following picture might help you to understand.
3-2. If you subculture isolated microbes into a sterile nutrient broth without any contamination, it will still be considered pure culture because it is single isolated species in a sterile aseptic environment of the nutrient broth.
3.3. A pure culture can become a mixed culture due to contamination. This could be caused by airborne bacteria if your conditions are not aseptic. Contamination is possible if the work area is not clean and sterile or if the glassware is not sterile. The contamination can transform your pure culture into a mixed culture and is hence problematic. So, it is very important to maintain a sterile and aseptic environment, glassware, and instruments.
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Answer:
Covariation of cause and effect
Explanation:
According to my research on different causes of behavior, I can say that based on the information provided within the question the term that best exemplifies this is Covariation of cause and effect. This term refers to the process of establishing that there is a cause and effect to relationship between the variables. In this situation the cause would be reading more newspapers, and the effect would be that the students display more knowledge of current events.
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Cones are concentrated at the center of retina called fovea centralis where no rod cells are present.
The retina is the innermost lining of the eye, made up of thousands of light-sensitive cells, with an inner part of nerve tissue and a pigmented outer part. It plays a fundamental role in the formation of images, which will be projected and then sent to the brain, through electrical impulses.
The retina consists of three types of layers: bipolar neurons, ganglion neurons and photosensitive cells.
Bipolar neurons promote the union of photosensitive cells with ganglion neurons, which are grouped with nerve fibers and thus originate the optic nerve. It carries nerve impulses to the brain. Photosensitive cells, due to their shape, are named in two types: cones and rods.
There are about 6 million cones that are concentrated in a small depression located in the macula lutea (center of the retina) called the fovea. They have an elongated and cylindrical shape, with conical outer segments. It is in this region that the image is most clearly formed, as they are stimulated by the most intense light. Cones are specialized in the accuracy of daytime vision and in recognizing color. There are three types of cones that have fundamental photopigments that respond to light of wavelengths (λ): cyanopigment - S cones (short λ) - sensitive to blue color, chloropigment - M cones (medium λ) - sensitive to green color and erytopigment - cones L (λ long) - sensitive to red color. The brain interprets the signals received by these cones, which allows it to process color differentiation.
Answer:
People wanted protection for number 1, and shrines for number 2.
Answer:
Most national parks preserve unique geographic features; Everglades National Park was the first created to protect a fragile ecosystem. The Everglades are a network of wetlands and forests fed by a river flowing 0.25 miles (0.40 km) per day out of Lake Okeechobee, southwest into Florida Bay.
Explanation:
