Both seta and cheta or chaete means bristles. I think the term can be used interchangeably . Just check this link:- http://en.wikipedia.org/wiki/Polychaete It about polychaetes a class of annelid worms. These are extracts form the passage:- Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called *chaetae, which are made of chitin. Indeed, polychaetes are sometimes referred to as bristle worms. Bundles of bristles, called *setae, project from the parapodia. http://en.wikipedia.org/wiki/File:Polychaeta_anatomy_en.svg Thats a cross section the terms have been used interchangebly.
Thr answer is D. Minerals
<u>endocrine</u> and <u>excretory</u>
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Different glands in the endocrine system (ex: the adrenal gland) produce hormones (ex: epinephrine/adrenaline) that circulate throughout the blood to regulate various cellular processes in various areas of the body.
The excretory system is responsible for the excretion of wastes from the body. This body system includes several organs from other body systems. For instance, the lungs are technically a part of this organ system (along with the respiratory system) because the lungs remove CO2 (a metabolic waste product from cellular respiration) from the blood and out of the body when you breathe out. Another, probably even more obvious example, of organs involved in the excretory system are the kidneys, bladder...etc (i.e. urinary system).
Radioactive elements are useful for the study of the biological system because of the unique properties which they possess. For instance isotopes of radioactive elements can be used to label a specific molecule in order to be able to follow the movement of this molecule as it navigates through the human system.
Answer:
A.The weak force acts within protons and neutrons, and the electromagnetic force has an infinite range.
Explanation:
Weak force explanis the interaction among subatomic particles (e.g. protons and neutrons) and is directly involved in the radioactive decay of the atoms. This is the reason that it has been well studied to understand nuclear fission reactions. Its range is very limited and does not exceeds beyond subatomic particles.
On the other hand, electromagnetic force is a very strong force that holds atoms together. It has infinite range. Once can assume the strength of this force from the basic understanding that, within an atom, electrons and protons exist together despite of their opposite charges. Nevertheless, the integrity of atom is not disturbed.
