Answer: Environmental experience
Explanation:
The correct answer is D.
From the scientific research conducted so far, we know that in the early Earth's history the atmosphere lacked oxygen and was mostly filled with other gases like methane. The increase in oxygen levels happened when the plants started producing oxygen as a byproduct of the process of photosynthesis.
The research so far also shows that the RNA was present before the DNA and that the microspheres might have been essential to the development of life on Earth.
<h2>Answer:</h2>
Option B, the diver will hear the sound first.
<h2>Explanation:</h2>
Sound need a medium to travel from one place to another, the medium where atoms are more closely packed together, the better will be speed of sound. That is why sound won’t travel in a vacuum because there are no particles to bump together to transmit the vibration.
- In air, the particles are generally far from each other so they travel further before they bump into one another.
- In water, the particles are much closer together, and they can quickly transmit vibration energy from one particle to the next. This means that the sound wave travels over four times faster than it would in air.
Answer:
The correct option is A. they evolved from land mammals.
Explanation:
Evolution can be described as a process through which organisms in a species change over a period of time due to the natural selection of the environment. Those organisms that have many similarities in their functions or structures are considered closer to one another and have the same common ancestors.
The properties mentioned in the question about cetaceans resembles the properties of land mammals. For example, cetaceans lack gills and breathe air. Land mammals also do not have gills and need to respire for living. The cetaceans have fin bones which are similar to the limb bones in the land mammals. Hence, these observations show that cetaceas have evolved from land mammals.
Answer:
The correct answer is methane . Nature constitutes most of the substances made up of organic compounds. These compounds have carbon atoms attached with hydrogen atoms with a chemical bond (very few compounds may not have this bond).
