Prokaryotes are singled cell/ unicellular
<h2>Fluorescence</h2>
Explanation:
The cells would fluoresce yellow in the presence of an inducer and yellow in the absence of an inducer
Normally,
In the presence of an inducer:
Inducer binds to the lac repressor and induce conformational changes causing dissociation of lac repressor from operator
In absence of lac repressor RNA Polymerase binds to the promoter and starts transcription of genes which catabolize lactose
In the absence of an inducer:
Without an inducer lac I gene produces lac repressor which binds to operator region and prevent binding of RNA Polymerase and thus blocks transcription
In case of fluorescence,
If there is mutation in lac operon,the operon becomes constitutive(continuous)
Mutation in lac I gene
Due to mutation in lac I gene lac repressor becomes defective and unable to bind with lac operator
Mutation in operator region
Due to mutation in operator region it prevents binding of lac repressor
Hence operon in the given conditions will be constitutive and yellow fluorescence will be observed in both cases(with and without inducer)
Answer:
The correct answer is: (A).
Explanation:
- In the question, it is mentioned that the algae can grow under the conditions of "enough sunlight" and "enough nutrients".
- Sunlight reaches the algae, by first falling on the surface made up of ice and snow and then refracting from there into the top layer of the ice where the algae grows.
- However, the capability of both snow and ice to reflect sunlight is far more than that of refracting sunlight.
- Therefore, the amount of light received by the algae is similar in absence or presence of the layer of snow on the top layer of ice.
- However, on deposition of snow on the layer of the ice, the weight of the ice increases and it sinks below into sea water.
- This allows more nutrient rich sea water to percolate into the ice and reach the algae.
- The algae receive more nutrients from the sea water and hence is capable undergoing better metabolism and growth.
- Hence, more algae are produced under such a situation.
Answer:
Synthesis is the phase of the cell cycle in which DNA is replicated, occurring between G1 phase and G2 phase. Since accurate duplication of the genome is critical to successful cell division, the processes that occur during S-phase are tightly regulated and widely conserved.
Explanation:
If a cell has not properly copied its chromosomes or there is damage to the DNA, the CDK will not activate the S phase cyclin and the cell will not progress to the G2 phase. The cell will remain in S phase until the chromosomes are properly copied, or the cell will undergo programmed cell death.