Answer:
the definition of migration is option B
Answer:
92.
Explanation:
92 chromatids are visible for humans at prophase stage because the replication of 46 chromosomes occur. When the replication of chromosomes occur, each chromosome is converted into two chromatids so when 46 chromosomes replication occur then it changed into 92 chromatids. So we can say that there is 92 chromatids in humans in the prophase stage of mitosis.
Answer:
used in an experiment as a way to ensure that your experiment actually work
Explanation:
In geology, a key bed (syn marker bed) is a relatively thin layer of sedimentary
rock that is readily recognized on the basis of either its distinct
physical characteristics or fossil content and can be mapped over a very
large geographic area.[1]
As a result, a key bed is useful for correlating sequences of
sedimentary rocks over a large area. Typically, key beds were created as
the result of either instantaneous events or (geologically speaking)
very short episodes of the widespread deposition of a specific types of sediment. As the result, key beds often can be used for both mapping and correlating sedimentary rocks and dating them. Volcanic ash beds ( and bentonite beds) and impact spherule beds, and specific megaturbidites
are types of key beds created by instantaneous events. The widespread
accumulation of distinctive sediments over a geologically short period
of time have created key beds in the form of peat beds, coal beds, shell beds, marine bands, black in cyclothems, and oil shales. A well-known example of a key bed is the global layer of iridium-rich impact ejecta that marks the Cretaceous–Paleogene boundary (K–T boundary). Please let me know if it works.
Answer:Primary succession occurs on land that is new and has never had a flora and fauna example: glacier retreats, lava flows. Secondary succession occurs on land that has been cleared example: by fire, of flora and fauna, but which still has viable seeds and spores in the soil.