Accor. to me correct answer should be BHow????===>***Sexual reproduction takes place through crossing over. of chromosomes of two different members (male,, and female) which leads to new genetic combination hence there are variations in the offspring (Product of Sexual reproduction ).

Hormones are responsible for the changes in the 3 phases in a life cycle.

Explanation:
Hormones are chemical messengers that are secreted by endocrine glands and travel through the bloodstream to target cells to regulate various physiological processes in the body. These hormones play a crucial role in the changes that occur during the different phases of a life cycle, including growth, development, and reproduction.

Let us understand how hormones are responsible for the changes in the 3 phases of a life cycle:

1. Juvenile phase:
During the juvenile phase, the body undergoes rapid growth and development. Hormones such as growth hormone, thyroid hormone, and insulin-like growth factor play a critical role in promoting growth and development of tissues and organs.

2. Reproductive phase:
During the reproductive phase, hormones such as estrogen and testosterone play a vital role in regulating the development and function of reproductive organs. These hormones are responsible for the onset of puberty, maturation of sperm and eggs, and the regulation of the menstrual cycle.

3. Senescence phase:
During the senescence phase, the body undergoes gradual decline in physiological functions, leading to aging. Hormones such as melatonin, growth hormone, and insulin play a critical role in regulating the aging process.

In conclusion, hormones play a crucial role in the changes that occur during the different phases of a life cycle. These hormones regulate growth, development, and reproduction of the body, and also play a significant role in the aging process.