Biology Crossword

the regions of the surface, atmosphere, and hydrosphere of the Earth occupied by living organisms.
the presence in or introduction into the environment of a substance or thing that has harmful or poisonous effects
the study of the economy
relating to or resulting from living things, especially in their ecological relations
physical rather than biological; not derived from living organisms
each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.
anything lower than 7 on the pH scale
anything higher than 7 on the pH scale
Any of the group of organic compounds consisting of carbon, hydrogen, and oxygen, usually in the ratio of 1:2:1
any of a class of organic compounds that are fatty acids or their derivatives and are insoluble in water but soluble in organic solvents. They include many natural oils, waxes, and steroids.
the central and most important part of an object, movement, or group, forming the basis for its activity and growth.
a small dense spherical structure in the nucleus of a cell during interphase.
a rigid layer of polysaccharides lying outside the plasma membrane of the cells of plants, fungi, and bacteria. In the algae and higher plants, it consists mainly of cellulose.
A group of compounds that pass electron from one to another via redox reactions coupled with the transfer of proton across a membrane to create a proton gradient that drives ATP synthesis.
Anaerobic may be used to describe an organism, a cell, a process or a mechanism that can function without air
A saclike membrane that contains the chlorophyll in cyanobacteria and in the chloroplasts of plant cells and green algae
the combination of two biological terms, plastid (an organelle in a plant cell), and chloros, which means green.
An organic compound that gives a characteristic color to plant or animal tissues and is involved in vital processes.
a microscopic single-celled organism that has neither a distinct nucleus with a membrane nor other specialized organelles.
an organism consisting of a cell or cells in which the genetic material is DNA in the form of chromosomes contained within a distinct nucleus.
the tendency toward a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes.
a soft tissue that composes muscles in animal bodies, and gives rise to muscles' ability to contract.
a system of the body that in vertebrates includes the brain, spinal cord, nerves, and sense organs and receives, interprets, and responds to stimuli from inside and outside the body.
relating to or denoting glands that secrete hormones or other products directly into the blood.
the system by which ingested food is acted upon by physical and chemical means to provide the body with absorbable nutrients and to excrete waste products