Neurotransmitters are chemicals that transmit signals across a synapse from one neuron to another.

Nitrogen oxides contribute to ozone formation, the greenhouse effect, and are a precursor to acid rain.

Nucleotides are the building blocks of nucleic acids and carry genetic information.

Oxygen acts as the final electron acceptor in the electron transport chain during aerobic respiration.

Oxytocin is a hormone that stimulates uterine contractions during childbirth and is also involved in social bonding.

Parathyroid hormone (PTH) increases blood calcium levels by stimulating the release of calcium from bones and increasing calcium absorption in the intestines.

Phytoplankton absorb carbon dioxide during photosynthesis, playing a crucial role in carbon storage in the ocean.

Phytoplankton are crucial for oxygen production through photosynthesis and play a significant role in the carbon cycle.

Plasmids are small circular DNA molecules that can replicate independently and are commonly used as vectors to transfer genes into host cells in genetic engineering.

Platelets are essential for blood clotting, helping to prevent excessive bleeding.

Platelets, or thrombocytes, are essential for blood clotting, helping to prevent excessive bleeding when injuries occur.

Preservatives are added to food to prevent spoilage and increase shelf life by inhibiting the growth of microorganisms.

Probiotics are beneficial bacteria that enhance gut health and improve digestion.

Producers convert solar energy into chemical energy through photosynthesis, forming the base of the food chain.

Ribosomes are the sites of protein synthesis, translating mRNA into polypeptide chains.

Ribosomes are the sites of protein synthesis, translating messenger RNA into polypeptide chains.

RNA plays a crucial role in both the transcription of DNA and the translation of proteins.

RNA polymerase is responsible for synthesizing RNA from a DNA template during transcription.

Root hairs increase the surface area for water absorption from the soil, facilitating the uptake of water and nutrients.

Sepals protect the flower bud before it opens and can also support the flower.

Sulfur is essential for the synthesis of amino acids and proteins, playing a critical role in plant metabolism.

Synovial fluid provides lubrication, nutrients, and shock absorption in synovial joints.

Temperature increases the number of charge carriers in semiconductors, thus increasing their conductivity.

Tendons connect muscles to bones, allowing for the transfer of force and movement.

The cambium is a layer of meristematic tissue that contributes to the growth in thickness (secondary growth) of stems and roots.

In an electrochemical cell, reduction occurs at the cathode.

The cell membrane regulates the transport of substances in and out of the cell.

The circulatory system's role is to transport nutrients, oxygen, and hormones to cells and remove waste products.

Coherent sources maintain a constant phase difference, which is essential for producing a stable interference pattern.

The endoplasmic reticulum is involved in the synthesis of lipids and proteins.