Answer:
Parasitism is when one species benefits and the other is harmed.
Mutualism is when both species benefit.
Commensalism is when one species benefits and the other species is neither harmed nor helped.
Answer: The answer is option B. Cell Walls
Explanation: Prokaryotic cells are much smaller than eukaryotic cells, have no nucleus, and lack organelles. All prokaryotic cells are encased by a cell wall. In eukaryotes, vertebrates don't have a cell wall but plants do.
Answer:
the answer is option D : 4
Lac genes are most effectively expressed in presence of Lactose and its analogs when glucose is absent.
Explanation:
A unit of prokaryotic gene expression and regulation,which includes structural genes and regulatory sequences recognized by regulatory gene product is called operon.
<em>Lac </em>structural genes are a part of<em> Lac</em> operon. The <em>Lac </em>operon consists of three, structural genes,an operator and a promoter.The product of Lac operon is involved in the conversion of disaccharide lactose into glucose and Galactose.
Lactose and its analogs are inducers of<em> Lac </em>operon. So, the structural genes are best expressed in presence of Lactose. Glucose and galactose are repressors of lac gene so the genes are repressed in presence of glucose.
It was the famous Theodor Escherich who is a famous German bacteriologist that discovered the E. coli and was also known for his research in the area of protein synthesis. In addition to that, Theodor Escherich discovered the bacteria type when he examined its samples from a patient suffering from gastroenteritis.
