Answer:
Option D, 63 cm
Explanation:
The scale of model is of local park is 
This means that each dimension of the model is 21 times smaller than the actual park (to be developed in future)
Given -
Depth of the pond 
centi meter
Depth of the real pond will be 21 times of the depth of the model.
Thus , real pond's depth is equal to
cm
Hence, option D is correct
In the process of photosynthesis glucose is produced from carbon dioxide and water <span />
Answer:
The lactose present prevents the production of lactase
Explanation:
This question is describing a set of genes in bacteria called LAC OPERON. Lac operon controls the production of lactase, which is the enzyme that digests lactose. However, this gene can be regulated at the transcription level i.e caused to be transcribed or not depending on certain factors.
According to the question, lac operon, which regulates the production of enzymes will be transcribed and subsequently translated i.e. turned on when there is a substrate (lactose) that the produced enzyme will work on. However, when there is no need of the lactase enzyme or there is absence of lactose (substrate), the lac operon gene is turned off.
Note that, the statement that "The presence of lactose prevents the production of lactase" is not correct.
