Human sperm and eggs contain 23 chromosomes. Human zygotes contain 46<span> chromosomes. The type of cell division that produces gametes with half the normal chromosome number is called meiosis. It is used to produce cells for repair and asexual reproduction.</span>
Answer:
The carbon cycle describes the way the element carbon moves between the Earth's biosphere, hydrosphere, atmosphere, and geosphere. It is important for a few reasons: ... One form carbon takes is the greenhouse gas carbon dioxide, CO2. Increased levels of carbon dioxide insulate the Earth, causing temperatures to rise
Answer:
The correct answer is option c, that is, variation.
Explanation:
In the given case, the gravel mix is to be selected on the basis of the size of pebbles, which is analogous to the organism selected in nature. In the given question, the sorting machine is analogous to the environment, that is, a selective force.
Like a specific environment permits the organisms exhibiting specific traits. For example, in a desert where the environment is hot and dry, only the species exhibiting the tendency to conserve water can thrive, similarly sorting machine will permit to distinguish gravel on the basis of the pebble size. Thus, different size of pebble resembles variation.