How are alleles for the same gene related

In what for do plants utilize nitrogen? why do they need nitrogen?

Which statement describes an endocrine function rather than an exocrine function? a. salivary glands release saliva into the mouth. b. sweat glands release sweat onto the skin c. the pineal gland releases melatonin into the blood. d. esophageal glands release mucus into the esophagus.

Idon’t know the answer and i’ve been stuck on it for a while now skskskskks