The study of the interactions and relationships of populations with each other and their abiotic environments.
A community of organisms and its abiotic environment.
The female gamete in sexual reproduction; also called an ovum.
An instrument that uses an electron beam to form clear and highly magnified images of microscopic structures. Electron microscopes cannot take pictures of living organisms.
electron transport chain(电子传递链)
The final stage of aerobic respiration. The electron transport chain establishes an electrochemical gradient across the inner mitochondrial membrane that powers the synthesis of ATP in oxidative phosphorylation.
Before birth, the maturing cells that will grow into a fully formed organism.
Control system of the body that functions by releasing hormones into the bloodstream.
Process by which liquids or small solid particles are taken into a cell in the form of small vesicles that are produced through the invagination of the cell membrane.
Sensory organ capable of detecting sound.
The progression of plant life and attendant animal life in a given geographic location, from pioneer plant to climax community.
A network of membrane-bound tubes and sacs in the cytoplasm. The endoplasmic reticulum is a major site of protein and lipid synthesis.
An interior skeleton found in vertebrates made of bone and cartilage.
Energy in a community can be depicted as a pyramid of food or biomass. The availability of food, biomass, and energy from the trophic level of producers up through each subsequent level on the food web is approximately 10 percent of that available in the previous trophic level.
Process by which molecules are secreted from the cell. Exocytosis occurs when a vesicle fuses with the cell membrane and releases its contents to the outside.
A rigid, chitinous protective structure that surrounds the bodies of arthropods and provides support.
Sensory organ capable of detecting light.
Biological catalysts made from proteins. Enzymes have attachment locations for substrates called active sites.
Hormone that stimulates the growth of the uterine lining during pregnancy and that develops and maintains the female secondary sex characteristics, such as the development of mammary glands, a narrower waist and wider hips, axillary and pubic hair, and a higher-pitched voice.
An organism whose cells have membrane-bound intracellular organelles, including a nucleus containing multiple chromosomes. Eukaryotes, unlike prokaryotes, can undergo sexual reproduction via meiosis. Compared to prokaryotes, eukaryotes are more complex and arose later in evolutionary history. Protists, fungi, plants, and animals are all eukaryotic organisms.
The organ system that filters blood and removes nitrogenous wastes from the body in the form of urea or uric acid. In humans, the two kidneys are the vital organs of blood filtration. In annelids, nephridia fill the filtering role; Malpighian tubules do the same in arthropods. In humans, other important structures of the system are the ureters, the urinary bladder, and the urethra.