Long thin tubular bundle of nervous tissue and support cells
The stomata must be open during the daylight hours to let oxygen and carbon dioxide pass through. While they are open, water vapor escapes into the atmosphere (transpiration). ... Transpiration is the loss of water through stomata, so, more stomata are found on the lower surface to prevent excessive loss of water.
In a lotus plant, stomata is found on the upper epidermis of the leaf.
Stomata are responsible for the exchange of gas with the surrounding atmosphere of the leaf. Their guard cells stay taut during the day to keep the stoma open.
Guard cells can only stay open if they are saturated with a certain quantity of water.
From this information we can infer that stomata are typically found on the lower epidermis to prevent water damage when it rains.
The rain would not only cover the openings, it would also ruin the osmotic balance of the guard cells causing inefficiency and damage to the cycle of gaseous exchange.
Natural selection probably selected against such plants giving rise to those with stomata on the underside.
The correct response is,
the sequences within the promoter region at -10 and -35 are the most important for recognition by the sigma subunit.
Promoter region is the DNA sequence located upstream of the corresponding gene. Promoters for genes are essential as RNA polymerase recognizes the promoter region and binds to it forming the holoenzyme complex which can inititate transcription of the gene located downstream.
Sigma factor is the transcription factor found in bacteria, RNA polymerase has a subunit for the sigma factor, this factor only can recognise the sequences in the promoter region and bind to it thus initiating transcription.
Promoters usually have 2 parts of conserved regions, -10 element and -35 elements. Both these regions have conserved sequences.
The sigma factor is capable of identifying these conserved sequences at these particular locations of the promoter and can bind to these sequences.
once the sigma factor binds to these regions, RNA polymerase too binds and forms a transcription initiation complex and then transcription of the downstream gene is initiated.
Therefore promoters need not have identical sequences for the sigma factor to bind, as long as the -10 and -35 regions have conserved sequences the sigma factor can bind and transcription initiation will be followed.
Answer:
2 mine take 80 man to drive across a mass drive to get a car in his car or something right now
