Answer:
Option (A).
Explanation:
Saddle joint is a type of synovial joint and also known as sellar joint. These joints are present in thumb, shoulder and inner ear.
The bone has one part concave inward and other part is convex outward. This bone can articulate with thumb's metacarpal and trapezium of the carpal bone. Saddle joints show abduction and adduction movements.
Thus, the correct answer is option (A).
The five successive stages of coal
formation are as follows:
step 1: plants decay
step 2: peat is formed
step 3: peat changes to lignite (soft
brown coal made from peat)
step 4: bituminous coal is formed
(black and brittle and very polluting)
<span>step 5: anthracite coal is formed
(highest amount of carbon and clean burning)</span>
Answer:
The answer is B Each group of three RNA bases codes for an enzyme that connects amino acids.
A Polypeptide chain is a sequence of amino acids that is the foundation for the basic structure of a protein
The answer has to do with trophic levels. As you probably know, the organisms at the base of the food chain are photosynthetic; plants on land and phytoplankton (algae) in the oceans. These organisms are called the producers, and they get their energy directly from sunlight and inorganic nutrients. The organisms that eat the producers are the primary consumers. They tend to be small in size and there are many of them. The primary consumers are herbivores (vegetarians). The organisms that eat the primary consumers are meat eaters (carnivores) and are called the secondary consumers. The secondary consumers tend to be larger and fewer in number. This continues on, all the way up to the top of the food chain. About 50% of the energy (possibly as much as 90%) in food is lost at each trophic level when an organism is eaten, so it is less efficient to be a higher order consumer than a primary consumer. Therefore, the energy transfer from one trophic level to the next, up the food chain, is like a pyramid; wider at the base and narrower at the top. Because of this inefficiency, there is only enough food for a few top level consumers, but there is lots of food for herbivores lower down on the food chain. There are fewer consumers than producers.
