Answer:
Answer is B.
nitrogen (78.10%), oxygen (20.90%) - this combination of gases dominate the Earth’s atmosphere.
Explanation:
The atmosphere of earth is a gaseous layer which surrounds the earth. It protects the life on earth by absorbing harmful ultraviolet radiation, reducing temperature extremes, maintaining the existence of liquid water on the earth's surface and warming the surface. The atmosphere consists of many gases including some pollutants and greenhouse gases. Nitrogen is the gas present in the atmosphere most abundantly while Oxygen and Argon take the second and third place. Atmosphere contains approximately 78% of nitrogen , 21% of oxygen and 0.9% of argon. Gases like carbon dioxide, nitrous oxides, methane, ozone and the water vapor constitutes the rest of the atmosphere. Many small particles called aerosols are also there which include dust, spores, pollen, volcanic ash, smoke etc. There are five layers of atmosphere. Troposphere (0 to 12 km) where we live is the lowest layer of earth's atmosphere ,which is closest to the earth's surface contains half of the atmosphere. Here most clouds are found and almost all weather occurs. Stratosphere (12 to 50 km) is the second layer where jet aircraft and weather balloons fly. It contains the ozone layer that absorbs harmful radiation from the sun. Mesosphere (50 to 80 km) is the third highest layer and the coldest part of the atmosphere where most meteors burn up upon entering in to the atmosphere. The fourth layer is thermosphere (80 to 700 km) where the International Space Station orbits earth and the space shuttles flew. Exosphere (700 to 10,000 km) is the outermost layer where the atmosphere merges into outer space. Most of the satellites orbiting earth are found here.
Answer:
Hippos likely formed around 15 million years ago from a cluster of anthracite, the very first whales arose over 50 million years ago, and the ancestor of both groups was aquatic. The first whales have been typical earth creatures, like Epictetus. They used to have large, carnivorous heads and sharp teeth.
Explanation:
Answer:
Can you put a gene from a certain species into a different species?
Can you put a gene from one organism into the same organism?
What is a new gene?
The correct option is D.
Although both bacteria and amoeba are unicellular organisms, the bacteria is considered to be a prokaryote because it lacks a true nucleus and membrane bound organelles and amoeba is considered to be a eukaryote because, it has a true nucleus and well defined cell organelles.
Answer:
The correct option is B. The stage of a virus where it is activated to perform the function for which it was intended is referred to as the triggering phase.
Explanation:
The life cycle of a virus consists of the following stages:
The Dormant phase:
In this phase, the virus doesn't take any action. It just manages to get into the system or software.
The Propagation phase
In this phase, the virus makes copies of itself.
The Triggering Phase
In this phase, the virus performs its function.
The Execution Phase
In this phase, the destruction made by the virus can be seen.
