Danish scientist Hans Christian Gram devised a method to differentiate two types of bacteria based on the structural differences in their cell walls. In his test, bacteria that retain the crystal violet dye do so because of a thick layer of peptidoglycan and are called Gram-positive bacteria. In contrast, Gram-negative bacteria do not retain the violet dye and are colored red or pink. Compared with Gram-positive bacteria, Gram-negative bacteria are more resistant against antibodies because of their impenetrable cell wall. These bacteria have a wide variety of applications ranging from medical treatment to industrial use and Swiss cheese production.
Answer:
YY là kiểu gen trội đồng hợp tử (2 alen Y). Kiểu hình của kiểu gen này có màu hạt vàng. Yy là kiểu gen dị hợp tử (một alen trội, một alen lặn). Kiểu hình của kiểu gen này có màu hạt vàng.
Explanation:
Answer:
The right response is "Natural killer".
Explanation:
- Natural killer cells constitute immune cells which could also identify and ultimately destroy distressed or damaged cells. This might also target cancerous as well as tumors.
- That alone reduces inflammation that lyses this same cell cycle rather than being amongst the very first cells towards prepare an inflammatory system, and even more so towards virus cells, participating including its destruction.
Answer:
The answer is when the cell express different genes.
Explanation:
Cell differentiation is the process when a cell is changed from one cell type to an other and brings more complexity to the system. A cell before differentiation possess all the genes however their expression in turned off. When some external or internal factors trigger the gene expression it starts the cell differentiation. A multicellular organism undergoes several rounds of cell differentiation during its development. Although cell differentiation changes the size, shape and metabolic activity but the genetic makeup or DNA is never changed during cell differentiation.
