(Originais Teachy 2024) - Question Hard of Sciences

Imagine that our body is like a very large city, and the blood needs to reach all parts of this city to deliver oxygen and nutrients. The circulatory system is like the road network of this city, with the heart being the central pumping station and the veins and arteries being the avenues and streets through which the blood travels. Based on what you have learned about the circulatory system, explain how the heart, veins, and arteries work together to circulate blood through the body and mention at least one important function of each of these components.

When the leaves fall from the trees, they begin to decompose on the forest floor. This decomposition process is very important for nature, as it releases nutrients that were stored in the leaves back into the soil. Fungi and bacteria play a key role in this stage of the life cycle, acting as decomposers. An experiment was conducted in a forest area where leaves from different trees were collected. Each set of leaves was placed in a separate container and kept under suitable conditions to observe decomposition. The experiment lasted several weeks and the students regularly noted the changes that occurred. At the end of the experiment, they compared the decomposition state of each set of leaves. Based on the natural cycle, the importance of decomposition, and the described experiment, what conclusion can be drawn about the role of the fungi and bacteria observed in the decomposition of leaves in the forest?

The ozone layer, located in the stratosphere, is responsible for filtering most of the ultraviolet radiation emitted by the Sun. Its role is crucial in protecting life on Earth, as excessive exposure to this radiation can cause serious damage to the skin and contribute to the development of skin cancer. However, the action of chemicals released into the atmosphere, such as chlorofluorocarbons (CFCs), has led to a process of ozone layer depletion, making it thinner and less efficient. Considering this context, answer: 1. Explain what CFCs are and how they are related to the destruction of the ozone layer. 2. Discuss the possible consequences for the planet if the depletion of the ozone layer continues at the current rate, considering the interactions between the ozone layer and the different terrestrial and marine ecosystems.