Diatoms have a distinctive two-piece wall of silica called a frustule.
Answer the following statement true (T) or false (F)
True
You might also like to view...
Why might a large number of competing microorganisms in a food sample result in lack of sensitivity of culture methods for detecting pathogens?
A. Many microbes secrete compounds that can be toxic for their competitors. If you need a pathogenic microbe to grow in a culture in order to detect it, these toxic compounds might inhibit the growth of the pathogen and impede the test. B. You can't obtain a pure culture from a food sample that has a large number of microbes present. It would be impossible to detect only one from within the sample. C. Culture methods often rely on biochemical changes taking place in medium for identification. With multiple microbes present, you may not be sure that the biochemical change observed is from the presence of a pathogen or from some other non-dangerous bacterium that also induces the biochemical change. D. The sheer number of microbes present might shut down the growth/replication of a pathogenic microbe in a food sample due to a 'starving out' effect. If it can't grow/replicate, it won't be detectable by a culturing method test. E. Many microbes secrete compounds that can be toxic for their competitors. If you need a pathogenic microbe to grow in a culture in order to detect it, these toxic compounds might inhibit the growth of the pathogen and impede the test AND culture methods often rely on biochemical changes taking place in medium for identification. With multiple microbes present, you may not be sure that the biochemical change observed is from the presence of a pathogen or from some other non-dangerous bacterium that also induces the biochemical change.
The term that refers to two hormones working together at a target tissue is ____
a. opposition b. permissive interaction c. priming interaction d. synergistic interaction e. commensal interaction
As water boils and turns to steam, what happens to the hydrogen bonds?
a. The hydrogen bonds break. b. The hydrogen bonds become stronger. c. The hydrogen bonds generate additional bonds. d. The hydrogen bonds form a crystalline lattice structure. e. The hydrogen bonds continually break and join together again.
Two bacterial strains have the same genes for metabolizing a carbohydrate, but one is wild-type for a regulatory inducer while the genetic variant does not produce the inducer. Which of the following statements is CORRECT with regard to the metabolic pathway enzymes?
A) The bacteria have the same phenotype. B) The bacteria have the same genotype but different phenotypes. C) The genotypes and phenotypes of the bacteria are the same. D) The bacteria are phenotypically the same but have different genotypes. E) The answer cannot be determined from the information provided.