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,
<span>They do not possess any skeleton at al</span>
Answer: Take out the trash regularly, make sure food is stored in secure containers, clean the house regularly, and don't leave perishable foods out for a long time.
