They have a cell wall and nucleus but they have no membrane-bound organelles like eukaryotic cells
Answer:
Mass is conserved in living systems through the processes of photosynthesis, cellular respiration, and the carbon cycle. It is demonstrated in cellular respiration through the process of braking down food to provide energy and releasing carbon dioxide.
Explanation:
Answer:
Antibiotic resistance can evolved in bacterial population in the following ways:
Explanation:
- In response to constant exposure to antibiotics some members of a bacterial population develop some beneficial mutations in some essential genes that gives them survival advantage in terms of food and space over the sensitive bacterial strains and hence they are capable of out-competing the sensitive bacteria.
- This happens due to the process of Natural Selection.
- These genes are called antibiotic resistance genes and bacteria usually carry them on plasmids in form of cassettes where genes resistant to multiple drugs are incorporated. These plasmids are called the MDR or Multi-Drug Resistance Plasmids.
- These resistant plasmids can be easily transferred among bacterial populations by conjugation, transformation or transduction or direct plasmid transfer.
- The resistant genes encode for proteins that render the drug ineffective by promoting their efflux from the cells, preventing their entry into the cell, chemically modifying them such that they become non-functional or altering the target site of the drug.
Answer:
Metaphase
Explanation:
In prophase, spindle fibers start emerging from the centrosomes. In metaphase, the spindle fibers attach to the sister chromatids.
