Which causes a drop in female hormone levels?

the onset of the menstrual flow

if an egg is released from the ovary

if the uterine wall thickens

if the egg is not fertilized

I will give brainliest

regulation of gene expression. gene expression can be regulated by various cellular processes with the aim to control the amount and nature of the expressed genes. these regulatory proteins bind to dna and send signals that indirectly control the rate of gene expression

explanation:

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".