Hard water is water that has a high mineral content. Hard water is formed when water percolates through deposits of limestone and chalk which are made up mostly of calcium and magnesium carbonates.
Answer:
chromosomes, the X and the Y.
Explanation:
Egg cells all contain an X chromosome, while sperm cells contain an X or Y chromosome. This arrangement means that it is the male that determines the sex of the offspring when fertilization occurs.
Answer:
Homologous structures can be described as the structures which are similar to one another present in different organisms. These similarities depict that the organisms might have a common ancestor i the past. For example, the forelimb of man, birds, dogs.
Analogous structures can be described as structures in different organisms which perform the same function but might not have a common origin. For example, the wings of bats and birds.
Explanation:
A prokaryotic cell lacks a nucleus, while an eukaryotic cell has a present nucleus.
