Answer:
Every hour 3 species disappear. Every day 150 species are lost.
Answer:
Explanation:
The flatworms are acoelomate organisms that include many free-living and parasitic forms. Most of the flatworms are classified in the superphylum Lophotrochozoa, which also includes the mollusks and annelids. The Platyhelminthes consist of two lineages: the Catenulida and the Rhabditophora. The Catenulida, or “chain worms” is a small clade of just over 100 species. These worms typically reproduce asexually by budding. However, the offspring do not fully detach from the parents and therefore resemble a chain in appearance. All of the remaining flatworms discussed here are part of the Rhabditophora. Many flatworms are parasitic, including important parasites of humans. Flatworms have three embryonic tissue layers that give rise to surfaces that cover tissues (from ectoderm), internal tissues (from mesoderm), and line the digestive system (from endoderm). The epidermal tissue is a single layer cells or a layer of fused cells (syncytium) that covers a layer of circular muscle above a layer of longitudinal muscle. The mesodermal tissues include mesenchymal cells that contain collagen and support secretory cells that secrete mucus and other materials at the surface. The flatworms are acoelomates, so their bodies are solid between the outer surface and the cavity of the digestive system.
Improving energy efficiency of a home generally means reducing the exchange of outdoor air (ventilation) with indoor air that can be contaminated with radon gas.
Explanation:
The presence of radon gas is not detectable by humans. It is odorless, colorless, tasteless, and radioactive. It can cause lung cancer over time and quantity breathed in. It enters buildings through cracks and voids in their foundations from the soil surrounding them.
The energy efficiency of buildings has been steadily increasing as we try to conserve energy and reduce costs. By so doing we also reduce the airflow between inside and outside, especially during the colder months of the year.
This practice will result in radon gas concentration buildup to values that could become unsafe for human consumption.
There are a number of methods to reduce the threat of radon gas in a house, but first there needs to be a measurement of the level of gas in the building. If the threat is high, the radon gas must be removed.
