Quick answer: Food enters the human digestive system through the mouth before then moving through the pharynx, esophagus, stomach, intestines, rectum and anus.
Answer:
Light energy is converted to chemical energy during photosynthesis.
Explanation:
Answer:
There are two possible answers: Deep-sea vents provided the energy needed for the first organic compounds to form OR self-replicating RNA molecules passed on genetic information.
Explanation:
The reason for the first answer is due to the hypothesis that indicates that life (organic molecules) arose from inorganic molecules synthesized from the amino acids in those energy vents. This is called the metabolism first hypothesis. The Miller-Urey Experiment provided evidence that organisms could rise from inorganic molecules (they simulated under the conditions you would see on early Earth). The second hypothesis is the RNA World hypothesis (second answer) which suggests that the formation of RNA that could replicate (possible due to mutation or evolution), led to life that could preserve its genetic integrity through replication (greater stability to the organism) and create lipid bi-layer membranes/other organelles. Some scientists support the Metabolism First Hypothesis, while others are skeptical (this goes for the RNA World Hypothesis as well). However, the RNA World Hypothesis is for more reasonable in the fact that its main point is the fact that RNA molecules were able to replicate and maintain genetic stability despite early Earth conditions. Although either hypothesis could explain why all organisms share the same genetic code, the RNA World Hypothesis better explains the universality of DNA/RNA of genes that we see today.
All living organisms are made of only 20 different aminoacids- this is the correct answer! This means that the genetic code only codes for those 20 aminoacids (for example Glutamine and Lysine).
The 20 aminoacids that can form proteins are also called Proteinogenic amino acids.
Soaring and gliding birds like eagle, vulture, albatross, sea gulls etc are efficiently adapted to utilize the air currents in their flight.
Explanation:
The soaring flight and gliding movements are special adaptation developed by birds to meet the challenge of increasing turbulent air current.
Birds have the extraordinary skill of flying smoothly and effortlessly even at very high altitudes
Birds soar by using thermal and dynamic soaring techniques.
Gliding movements help the birds to deflect the wind downward which helps to lift their bodies in the air. They do not flap their wings during gliding but just dive straight into the air which helps to increase their speed.
The adaptation of the bird’s structure with very light but strong bones on their wings helps to soar and glide in the air.
