Yes because they remain closed always show chances is only self pollination

Fertilisation is the most critical event in sexual reproduction. It is the process by which the sperm and the egg fuse together to form a zygote, which is the first cell of the new organism. Fertilisation is a highly regulated process that involves several steps, including:

1. Sperm maturation: Sperm cells are produced in the testes and mature in the epididymis. During this process, the sperm gain the ability to swim and fertilise the egg.

2. Ovulation: The process by which the mature egg is released from the ovary and travels down the fallopian tube towards the uterus.

3. Sperm transport: The sperm must travel through the cervix, uterus and fallopian tubes to reach the egg.

4. Sperm-egg recognition: The sperm must recognise and bind to the egg cell membrane, which is coated with special proteins.

5. Fusion of gametes: The binding of the sperm to the egg triggers a series of chemical reactions that allow the sperm to penetrate the egg and fuse with its nucleus.

6. Zygote formation: Once the sperm and egg nuclei fuse, they form a single cell called a zygote, which contains all the genetic information necessary for the development of a new organism.

Importance of fertilisation:

1. Genetic diversity: Fertilisation ensures genetic diversity by combining the genetic material from two different individuals, which results in unique offspring.

2. Embryonic development: Fertilisation is crucial for the initiation of embryonic development, which is the process by which the zygote develops into a complex multicellular organism.

3. Species preservation: Fertilisation is essential for the preservation of species by ensuring the continuation of genetic material from one generation to the next.

4. Reproductive success: Fertilisation is necessary for reproductive success, as it is the first step in the formation of a new individual.

In conclusion, fertilisation is the most critical event in sexual reproduction as it is essential for genetic diversity, embryonic development, species preservation, and reproductive success.