1) Scientists believe that the ancient ancestors of all animals were <span>single-celled eukaryotes that sometimes grew in colonies.
</span>Eukaryotic cells have membrane-bound organelles such asmitochondria<span> and the Golgi apparatus.
</span>The best answer is :
<span>B) single-celled eukaryotes that sometimes grew in colonies</span>
Answer:
True
Explanation:
Development, together with globalization, drove severe changes at a global level. The natural and original environments suffered from these effects and still are.
Human beings have constantly been altering the natural ecosystems and causing irreparable damages to nature. For many decades, development involved society and technology advance over new areas unpopulated by humans.
<u>Some</u> of the principal human activities responsible for biodiversity loss are
- the uncontrolled use of unrenewable resources,
- overexploitation of renewable resources;
- land destruction for the mining industry, farming and cattle industry, buildings, and other infrastructures;
- the unplanned advance of cities, and opening of new roads to connect those cities.
All of them involving
- deforestation and fragmentation of natural landscapes;
- water, air, and soil pollution,
- species loss, and reduction of biodiversity.
With globalization, transport around the world became normal. And when traveling around the world, new species are intentionally or unintentionally transported too. When these species, of animal or vegetable origin, get established in a new area, they overgrow to the point of turning invasive.
Invasive species are uncontrollable and cause severe damage in native endemic species by competing for resources. The whole ecosystem structure changes.
But there are some background glitches in the system that are the principal responsible for all the mentioned activities. Some important aspects are lacking
- The respect for nature,
- People´s education at different levels to care and protect wildlife,
- Interest in keeping ancestral knowledge,
- Planning and previous environmental impact studies,
- Policies to control human activities,
- Caring involved government.
If, as a society, we lack these aspects, the possibilities of changing our impact on nature are far away.
The best answer is A. The purpose of the cell wall is to hold the cell in a specific shape, usually rectangular or square. For example, a plant cell's wall keeps it rigid so that the plant can stand up.
If the cell does not have a wall, it can easily change shape to accommodate for things coming in and out of the cell.
Hope this helps!
For most athletes, the period in their
yearly training cycle during which it is recommended to begin calorie restriction
so as to lose significant amounts of stored body fat is the off-season or early
in the preseason. Restriction of energy intake late in the preseason when
there is rigorous training or during season when there is competition may impede training, recovery,
or performance.
