Hint: A gland is a community of cells in the body of an animal that synthesises substances such as hormones that releases into the bloodstream (endocrine gland) or cavities within the body or its outer surface (exocrine gland).
Complete answer: The seminal vesicles, prostate gland, and bulbourethral glands (also known as Cowper's glands) are male accessory glands (MAG) in humans. Male accessory glands in insects manufacture items that combine with sperm to protect and preserve it, including seminal fluid proteins. The seminal vesicles are saccular glands located posterior to the urinary bladder. The fluid from the seminal vesicles is viscous and includes fructose, which serves as an energy source for the sperm; prostaglandins, which aid in sperm movement and viability; and proteins, which induce minor coagulation reactions in the sperm after ejaculation. The prostate gland is a firm, dense structure found just below the urinary bladder. It's about the size of a walnut and wraps around the urethra as it exits the urinary bladder. Prostate secretions are small, milky in colour, and alkaline. They work by increasing the motility of the sperm. The bulbourethral (Cowper's) glands are found near the base of the penis and are around the size of a pea. The bulbourethral glands secrete an alkaline mucus-like fluid in response to sexual stimulation. This fluid neutralises the acidity of urine residue in the urethra, aids in the neutralisation of vaginal acidity, and provides some lubrication for the tip of the penis during intercourse. Seminal fluid, also known as semen, is a slightly alkaline mixture of sperm cells and accessory gland secretions. The seminal vesicles secrete approximately 460\%$ of the amount of the sperm, with the prostate gland producing the majority of the remainder. Sperm and bulbourethral gland secretions contribute only a small amount.
Note: The volume of sperm in a single ejaculation can range between 1.5 and 6.0 ml. There are usually 50 to 150 million sperm per millilitre of sperm. Fertility issues normally arise when sperm counts fall below 10 to 20 million per millilitre. While only one sperm penetrates and fertilises the ovum, it takes several million sperm in an ejaculation to ensure fertilisation.