1. What is an operon? a. The binding site for a repressor PRO.

b. Any group of genes responsible for the metabolism of lactose in a prokaryotes or eukaryotes.

c. A cluster of genes under the control of a promoter.

d. A regulatory gene.

your answer is rna to the question.

volcanoes (an event in the geosphere) release a large amount of particulate matter into the atmosphere. these particles serve as nuclei for the formation of water droplets (hydrosphere). rainfall (hydrosphere) often increases following an eruption, stimulating plant growth (biosphere).

i don't know. if i were you, i would search it up online : d

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.