Answer:
- <u>Conventional plastics-</u>
"Plastics are typically organic polymers of high molecular mass, but they often contain other substances."
"Oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination.
- <u>Biodegradable plastics</u>-
"They are largely manufactured from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers."
Explanation:
<u>Complex Issue-</u>
- Diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all ‘good’ or petrochemical-based products are all ‘bad’.
- Biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted.
Transmit nerve impulses within the nervous system.
Answer:
to exchange oxygen with carbon dioxide
Explanation:
The structure depicted in the figure are called alveoli which are sponge like in nature. They are the primary site for the exchange of carbon di oxide and oxygen from and to the bloodstream.
Structurally they are like tiny balloons that look like a bunch of grapes as depicted in figure. They are present at the extreme end of the respiratory system after bronchioles. They are arranged in the form of groups of these small balloon like structures.These are the final sites where carbon dioxide leave and oxygen enter in our blood.
When air enters into our nose, it passes through different structures like larynx, trachea and lungs. There are many smaller structures in lungs like a maze,like bronchi, bronchioles and after bronchioles the air reaches into alveoli.
Since alveoli are extremely tiny and thin structures containing a network of capillaries embedded in them, these are the sites where gases are able to exchange. CO2 leaves and O2 enters the blood.To get inside the blood, oxygen moves through the process of diffusion into the alveolar epithelium, that is a capillary endothelium and a thin interstitial space.
Hope it help!
