1. Enterococcus and coliforms can enter the water through feces. Although a water sample is negative for these bacteria, it could still be infected by pathogens from other sources than feces.
2. Culture media are sterilized by filtration because they could contain antibiotics or serum which deteriorate upon heat. Filtration is used in sanitation to remove large particles.
3. In the membrane filter technique, it is assumed that <span>all viable bacteria will form colonies. This means that formed colonies develop from the viable bacteria so that the number of colonies suggests the number of bacteria.
4. E. coli is negative for Citrate and Voges-Proskauer tests, and is positive for Indole and Methyl red tests.
5. The answer is yes because eo</span><span>sin-methylene blue agar is inhibitory to Gram+ bacteria.</span>
Starch is a high molecular weight substance; therefore, it is insoluble to our cells. It needs to be broken down to simple sugars like glucose in order for it to be dissolved/absorbed in our blood. This is because simple sugars has smaller molecular weights and are more soluble.
Answer:
A. Scientists discovered chromosomes and DNA.
Explanation:
Mendel's ideas were based on patterns of inheritance in plants. Although he identified these patterns, at the time, we did not know what the hereditary material was. This means Mendel couldn't uncover the mechanism of why he was seeing the patterns he was.
When scientists discovered chromosomes and DNA, they were able to see how Mendel's observations made sense in the context of DNA and chromosomes.
Answer:
it represents the mating between males and females is shown by a horizontal line between their respective symbols.
Explanation:
Answer: The simplest way is to determine if a strain is mutant is observing morphology, growth rate, double time, etc but it is accurate if you can prove if the strain is deficient in one aminoacid or can't metabolize lactose, etc.
Explanation: A wildtype strain functions normally, for example, can metabolize as a carbon source, glucose, lactose and other sugars, can synthesize all the aminoacids requered for protein synthesis, etc. If a strain suffers a mutation and it is inheritable, the strain become a mutant. Since several mutations can be silent ones, only those that interfere with a process, can be assesed easyly.
For example, if you have several strains and put them in a lactose medium, but some of them cannot growth means that are lactose mutants. Those strains could carry a mutation in genes that encode lactose degrading enzymes or in regulatory genes of the lac operon, etc.
