If you are talking about frequency in terms of waves, it is in seconds^-1
Answer:
D. A mutation causing uncontrolled cell division
Explanation:
Cell division is controlled by various mechanisms. Any mutations in the genes regulating the cell division lead to uncontrolled cell division. Loss of control over the process of cell division leads to the formation of tumors.
These tumors may cause cancer if they are transformed into malignant tumors. Hence, a mutation that causes loss of control over cell division is harmful.
Living things obtain and use energy so alive?
Answer:
E) Either anaphase I or II
Explanation:
Failure of segregation of homologous chromosomes during anaphase I or failure of segregation of sister chromatids during anaphase II leads to the presence of the abnormal number of chromosomes in resultant gametes. In the given example, the egg mother cell with 48 chromosomes (24 pairs) would enter meiosis I but the failure of one pair of homologous chromosomes to segregate from each other followed by normal meiosis II would result in the formation of two gametes with one extra chromosome and two gametes with one less chromosome.
On the other hand, if the nondisjunction occurs at anaphase II of meiosis II, two normal gametes, one gamete with one extra chromosome and one gamete with one less chromosome will be formed. Therefore, nondisjunction at anaphase I or anaphase II would have resulted in the production of eggs with one extra chromosome.
Internal fertilization is the process when the syngamy (union of male and female gamete) occurs inside the female body after insemination using copulation. In contrast, External fertilization is the syngamy outside the female body, that is in the outer environment especially in water bodies.