Answer:
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. ... Slate is frequently grey in color, especially when seen, en masse, covering roofs.
first, third, fourth, second
Answer:
Crossing over ensures that organisms of the same parents have differences in genetic content making them unique in one way or the other.
Explanation:
This question is describing the process of crossing over, which occurs only during prophase I of meiosis. During the process of crossing over, alleles of a gene are exchanged between non-sister chromatids of homologous chromosomes (mother and father chromosomes).
Hence, a unique GAMETE that has been genetically recombined will be formed. When these gametes are fertilized (egg) or fertilizes (sperm), organisms that are genetically different from their parents are produced. This ensures genetic variation, which is a difference in the genetic content of organisms.
The population of blue crabs will be difficult for the scientists to count because of unreliable ways and natural phenomenon or occurrence that causes the water's temperature to rise. According to climate reports, year 1999 have warmer temperature and this probably caused the blue crabs to be active, but on year 1990 female blue crabs sustained a normal quantity of production of their species. Thus, the estimated count of population of blue crabs is probably more accurate in year 1990 than year 1999 because of the stable production of the female crabs.
