The most important trait that modern fish had developed was the transformation of their skeleton from cartilage to bones. This was called ossification. Eventually, bony fishes and sharks dominated the waters because their body structure development which helped them as swimmers is advanced compared to earlier fishes.
Answer:
Explanation:a
majority of an atom's mass is found its protons and neutrons, subtracting the number of protons (i.e. the atomic number) from the atomic mass will give you the calculated number of neutrons
Nondisjunction is most likely responsible for the failure of a gamete to receive a copy of a particular chromosome.
What is non-disjunction?
When a pair of homologous chromosomes fails to segregate or separate at anaphase, both of the pair's chromosomes pass to the same daughter cell. This most likely happens during meiosis, but it can also happen during mitosis to create a mosaic individual. These are some potential causes of nondisjunction, while the exact cause or causes are unknown. Growing maternal age is linked to trisomy 21 and trisomy 18 fetuses and newborns, indicating that the mother's age may be a significant etiological component. Chromosomal structural defects such translocations and pericentric inversions might hinder chromosome pairing during meiosis and encourage nondisjunction.
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It will be Control. Part of the experiment used to show that the results of an experiment is really due to the conditions being tested.