Producers are green plants or photosynthetic organisms that are the basis for the other living parts of any ecosystem. Producers need to have access to light to produce food. Few producers will be found deep below a lakes surface simply because the deeper you travel under water the less light penetrates those deeper layers.
Answer:
These are Cowpers's gland.(Bulbo Urethral Gland)
Explanation:
These are small pea-sized glands at the base of the penis which connect each with the urethra through a short duct. It is thorough this ducts that secretion from each gland gets to the urethra.
They secretes thick alkaline fluids for lubrication of urethral and tip of the penis, for expulsion of left over urine, dead cells, mucous from the urethra for clean sperm passage.
The serrations also neutralise the acidity of the urethral
Half a wavelength must fit exactly into the length of a vibrating cord.