Gram's staining is a differential staining technique that employs a primary stain like crystal violet and a counter stain like safranin along with the decolourizing agent alcohol and a mordant called the Gram's iodine.
Iodine is a mordant added after the primary stain. It fixes the stain by combining with it to enchance the staining ability. This forms an insoluble crystal violet iodine complex appearing purple under the microscope. These microorganisms are classified as Gram positive.
If addition of iodine is skipped, crystal violet is not fixed on the slide and the insoluble complex is not formed. The cells are decolourized by alcohol and are stained by the counter stain safranin making the Gram positive cells wrongly indentified as Gram negative due to its pink colouration. Thus, the slide will show all the cells as pink coloured Gram negative cells.
A biodiversity hot spot is a relatively small region with a significant number of indigenous species and endangered or vulnerable species.
Ecologically distinct areas with extraordinarily high species densities are known as biodiversity hotspots, and they are thus top priorities for nature conservation. The term "biodiversity" has several meanings. A species area must satisfy two severe requirements in order to be considered a biodiversity hotspot: It must have a significant proportion of plant life that is endemic, or found nowhere else on the earth, and at least 1,500 vascular plants. In other terms, a hotspot is unique.
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B. Homozygous that has two identical alleles for a particular trait
Answer:
104
Explanation:
Cause since one sperm cell contains 104 chromosomes and ts sperm cell is what isin him, it's still 104. I'm so sorry I can't really explain it but hope it helped
Answer:
a. Acts as a repressor (inhibits transcription from the lac operon)
Explanation:
LacI is a repressor protein that plays an important role in lac operon. Lac operon is usually switched off i.e. it is inactive in absence of lactose and presence of glucose. The operon has an operator region, promoter region and structural genes.
In absence of lactose, LacI repressor binds to the operator area. Since operator region overlaps with the promoter region, RNA Polymerase is not able to bind to promoter due to presence of repressor. Transcription of lac operon genes does not take place. When lactose is present, some of it is converted into allolactose. Allolactose binds to LacI repressor making it change its shape. The repressor is no longer able to bind to operator region and RNA Polymerase is free to transcribe the genes making the operon active.
