The cell membrane is semi permeable in nature, that is, it allows the passage of some substances while it disallows some substances. Small and non polar molecules pass quite easily through the cell membrane but large and polar molecules can not do this.
The substances which can easily pass through the cell membranes make use of passive transports such as diffusion and facilitated diffusion to enter the cells while substances which can not pass through the cell membranes on their own make use of active transport. Examples of active transport are endocytosis and ectocytosis,
Answer:
silicon dioxide Si02 and diamond
Explanation:
because it's commonly found in nature
ADP (adenosine diphosphate)
A Ribosome is composed of ribosomal RNA and proteins.
They are made in the cell nucleus, in two types of subunits, the large and the small.
The subunits go to the cell body, where they can float free in the cytoplasm or attach to the rough endoplasmic reticulum.