Tiktaalik is a transitional fossil which shows how fish evolved into amphibians and reptiles. So the correct option is B.
What is Tiktaalik?
Tiktaalik is a direct ancestor of tetrapods or four-legged animals. It is an extinct fish-like animal and it lived on earth 380-385 million years ago (Devonian period).
The word Tiktaalik is derived from the <em>Inuktitut</em> language which loosely translates to large freshwater fish. This animal had characteristics of both fish and tetrapod and is therefore called the link between these two kinds of animals.
The characters resembling fish are gills and scales and the characters resembling tetrapods are rib bones, movable neck and lungs. There are characters that are a mix of both tetrapods and fish. These are bones and joints in limbs but fish-like fins instead of feet or hands.
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Carlos will have to consume about 63 gram of protein per day.
The dietary reference intake of protein is 0.8 gram of protein per kilogram body weight or 0.36 gram per pound. Carlos is 175 pounds in weight, so he is going to need 0.36 * 175 = 63. Thus, Carlos needs 63 grams of protein per day.<span />
Answer:
Human activities affect the flow of energy and matter in an ecosystem and alter the energy balance in ecosystems through the unsustainable nature of what they do. The energy flow is affected in several ways as a result of pollution, overpopulation, deforestation, burning fossil fuels, etc. Such changes have stimulated soil erosion, climate change, causing water unfit to consume, poor quality of air and so on. When humans cause a change in the energy balance, they impact the ability of the ecosystem to respond and adapt to changes in the environment. It is like getting a cut, but it never heals and grows bigger instead.
Answer:
The answer is: Receptor A because the ligand concentration is greater than the Kd.
Explanation:
Receptor A because the ligand concentration is greater than the Kd., because the conformation of a receptor protein composes the functional state. Ligands include substrates, inhibitors, activators, and neurotransmitters. So, Affinity is a measure of the strength of attraction between a receptor and its ligand.
Answer:
The correct answer is option b. "20 H1, 40 H2A".
Explanation:
Chromatin is a complex that protects and condenses the genetic material comprised of DNA and proteins. When chromatin is in the form of a 30 nm fibril, nucleosomes have a regular positioning along the DNA. This means that each nucleosome is associated with a single H1 molecule. Therefore a chromatin containing 20 nucleosomes will have 20 copies of H1 and 40 copies of H2A, because each nucleosome has 2 copies of the core histone H2A.