Formation of the Earth's Atmosphere. The early Earth was very different from our Earth today. The early Earth experienced frequent impacts from asteroids and meteorites and had much more frequent volcanic eruptions. There was no life on Earth for the first billion years because the atmosphere was not suitable for life.
Answer:
Natural selection
Explanation:
Natural selection occurs when one allele (or combination of alleles of different genes) makes an organism more or less fit, that it is able to survive and reproduce in a given environment. If an allele reduces fitness, its frequency will tend to drop from one generation to the next.
It portrays the neuromuscular junction of a skeletal muscle.
The breakdown items are consumed by the pre-synaptic neuron by endocytosis and used to re-combine more neurotransmitter, utilizing vitality from the mitochondria. The Cytoplasm in the Synaptic Knob has a high extent of specific organelles. These incorporate smooth endoplasmic reticulum, mitochondria, and vesicles.
Answer/Explanation:
In humans, we breathe in oxygen via the respiratory system. The oxygen enters the lungs. The air sacs in the lungs - the alveoli - are the site of gas exchange in the lungs and are where the circulatory and respiratory systems interact.
The alveoli take in the oxygen, where it diffuses into the capillaries (circulatory system). Blood, which passes through the capillaries takes this oxygen to all the cells in the body. Oxygen binds to haemoglobin in red blood cells, which transport it around the body.
Additionally, blood also transports carbon dioxide back to the alveoli of the lungs, where it diffuses into the lungs and is expelled when we breathe out
