Answer:
A major factor in determining the mode of nitrogen excretion is the availability of water in the environment. Generally, aquatic animals excrete mostly ammonia, whereas terrestrial animals excrete either urea or uric acid.
Explanation:
Answer:
Cancer is basically a disease of uncontrolled cell division. Its development and progression are usually linked to a series of changes in the activity of cell cycle regulators. For example, inhibitors of the cell cycle keep cells from dividing when conditions aren’t right, so too little activity of these inhibitors can promote cancer. Similarly, positive regulators of cell division can lead to cancer if they are too active. In most cases, these changes in activity are due to mutations in the genes that encode cell cycle regulator proteins.
Explanation:
A Negative stain such as India ink or Congo red-Look for the presence of a capsule.
This stain method is usually used to stain the area around the microorganism.
B The Gram stain-Divide bacteria into two groups based on cell wall structure (thick vs. thin).
This is type of differential staining used to distinguish organisms based on their staining properties. Gram + and Gram- bacteria stain different because of different cell wall structure.
C The Ziehl-Neelsen Acid-fast stain- Identify bacteria with waxy cell walls such as: Mycobacterium tuberculosis (the cause of TB).
This is also differential staining method which uses heat and phenol to derive dye into the cells with lipid-rich walls.
D Simple stain with a basic dye-Stain microbes a bright color to make it easier to see them in bright field microscopy.
One dye is used in simple staining in order to determinate the size, shape and arrangement of the cells.
E The Schaeffer-Fulton Endospore stain-Identify Bacillus or Clostridium species, such as the causative agents of anthrax, botulism, tetanus and gangrene.
This is a special type of staining only used for the bacteria that can form endospores. Bacteria are first treated with heat and then with malachite green, which is very strong stain that can penetrate endospores.
your body and nature is about human life
Answer:
It has incomparable advantages over other gene editing tools.
Explanation:
For example, the CRISPR-Cas9 system has more target sites than ZFNs and TALENs, and Cas9 has many variants that can be used in a variety of studies. Moreover, the system is extremely easy to use and can be executed in almost any laboratory.
The most important advantages of CRISPR/Cas9 over other genome editing technologies is its simplicity and efficiency. Since it can be applied directly in embryo, CRISPR/Cas9 reduces the time required to modify target genes compared to gene targeting technologies based on the use of embryonic stem (ES) cells.
Disadvantages of CRISPR technology: CRISPR-Cas9 off-target; The effect of off-target can alter the function of a gene and may result in genomic instability, hindering it prospective and application in clinical procedure.
this the best i got, hope it helps :)
