Statement 1: Unisexual flowers are either staminate flowers or pistillate flowers.
Statement 2: Both monoecious and dioecious plants have unisexual flowers.
A) Both statements 1 and 2 are correct.
B) Statement 1 is correct but statement 2 is incorrect.
C) Statement 1 is incorrect but statement 2 is correct.
D) Both statements 1 and 2 are incorrect.

Hint: Monoecious and dioecious are terms that refer to plant reproduction. Mono means single and di means two. In plants, unisexual and bisexual flowers can be found. Presence of stamen or carpels differentiates the flowers into unisexual and bisexual.

Complete answer:
Flowers with either female reproductive organ or male reproductive organs are known as unisexual flowers. In flowering plants, the unisexual male flower which bears the stamens is known as staminate. Similarly, the female flower bearing pistils is called a pistillate. Hence, unisexual flowers can be either staminate or pistillate flower. Therefore, statement 1 is correct.

Unisexual flowers can be distributed on plant species in different arrangements resulting in a spectrum of sexual forms. Those arrangements are monoecious, and dioecious. Monoecy is characterized by pistillate (female) and staminate (male) flowers on the same individual plant. Dioecy is characterized by female and male flowers on different individual plants. In some flowering plants, both female and male flowers may be present on the same individual plant (monoecious) or on separate plants (dioecious). Therefore, statement 2 is incorrect.

Hence, the correct answer is option (B).

Note: Dioecy is of particular evolutionary significance because it is analogous to the sexual systems found in most of the animals and is therefore a striking example of parallel evolution across the animal and plant kingdoms. Holly flower is the common example of a dioecious plant. Holly plants are either female or male. On the male holly plant flowers with the anther can be seen, and on the female holly plants are flowers with the pistil—the style, stigma and ovary are seen.