Proliferative phase of menstrual cycle is characterized by increased secretion of estrogens while luteal phase is charecterized by increased secretion of progesterone

Answer

### Step-by-Step Text Solution:

1. **Understanding the Menstrual Cycle Phases**: The menstrual cycle is typically divided into several phases: the menstrual phase, the follicular phase, ovulation, and the luteal phase. The proliferative phase is part of the follicular phase.

2. **Proliferative Phase**: During the proliferative phase, which occurs after menstruation and leads up to ovulation, there is an increase in the secretion of estrogens. This is primarily due to the action of Follicle Stimulating Hormone (FSH) which stimulates the growth of ovarian follicles.

3. **Role of Estrogens**: Estrogens are responsible for the thickening of the endometrial lining in preparation for a potential implantation of a fertilized egg. This phase lasts until ovulation, which typically occurs around day 14 of a 28-day cycle.

4. **Luteal Phase**: After ovulation, the cycle enters the luteal phase. This phase is characterized by the secretion of progesterone, which is produced by the corpus luteum (the remnant of the follicle that released the egg).

5. **Role of Progesterone**: Progesterone plays a crucial role in maintaining the endometrial lining and preparing it for a possible pregnancy. If fertilization does not occur, the corpus luteum degenerates, leading to a decrease in progesterone levels, which ultimately triggers menstruation.

6. **Conclusion**: The statement in the question is correct: the proliferative phase is characterized by increased secretion of estrogens, while the luteal phase is characterized by increased secretion of progesterone.