The link between a first messenger and a second messenger in a cell that responds to peptide hormones is usually

A G- protein

Explanation:

G proteins are molecules involved in signal transduction. They are often referred to as guanine nucleotide binding proteins. They bind to signal molecules at the exterior of the cell and are responsible for transmitting the signals from the exterior of a cell to the inside of the cell, which then results to a cellular response. G proteins are generally activated by a set of trans-membrane receptors called G protein coupled receptors and then deactivated by a set of proteins called the Regulator of G protein signaling (RGS proteins). In regulation, G proteins bind to GTP when they are active, but bind to GDP when they are inactive.

metamorphism is the change of minerals or geologic texture (distinct arrangement of minerals) in pre-existing rocks (protoliths), without the protolith melting into liquid magma (a solid-state change). the change occurs primarily due to heat, pressure, and the introduction of chemically active fluids. i hoped i !

a

explanation:

many plants naturally reproduce this way, but it can also be induced artificially. horticulturalists have developed asexual propagation techniques that use vegetative plant parts to replicate plants. success rates and difficulty of propagation vary greatly. monocotyledons typically lack a vascular cambium and therefore are harder to propagate.