sat关于生物方面的高频词汇

在sat考试的备考中，有时候会要求考生熟悉关于生物方面的一些高频词汇。本站小编为大家精心准备了sat考试关于生物方面的一些常考的'高频词汇，欢迎大家前来阅读。

Decomposer(分解者)

Organisms that consume waste products and dead organic material and constitute part of the food web, which also includes producers and consumers. Also called saprophytes. Decomposers liberate inorganic elements such as nitrogen and carbon and allow those elements to move back into their respective chemical cycles. Examples of decomposers are bacteria and fungi.

dehydration synthesis(脱水缩合)

A common biochemical reaction in which a new compound is formed by the joining of two compounds to release water. Occurs in the synthesis of polysaccharides and polypeptides. The reverse of hydrolysis.

deoxyribonucleic acid (DNA/脱氧核糖核酸)

A type of nucleic acid polymer built from sugar-phosphate backbones and nitrogenous bases. DNA’s sugar, deoxyribose, has one fewer oxygen atom than ribose, found in RNA. The nitrogenous bases adenine, cytosine, guanine, and thymine are used in DNA.

Dicot(双子叶)

A flowering plant (angiosperm) that possesses two cotyledons during embryonic development. Usually has taproots, flower parts in multiples of fours and fives, and branching veins in leaves.

Diffusion(扩散)

The transport or natural drift of molecules traveling from an area of higher concentration to an area of lower concentration. Diffusion does not require outside energy from the cell.

digestive system(消化系统)

The system of organs that converts food to usable nutrients through mechanical and chemical breakdown. Important components of the system are the alimentary canal, glands, esophagus, stomach, small intestine, large intestine, and rectum.

diploid number(双倍目)

The total number of chromosomes present in a somatic cell. The diploid number is twice the haploid number. In humans, the diploid number is 46.

Disaccharide(双糖)

A sugar compound consisting of two carbohydrate monomers.

Dominant(显性【尤指基因显性】)

Refers to an allele that controls the phenotype even when a different allele is also present, as in a heterozygote. Can also refer to the trait or phenotype produced by a dominant allele. Also known as Mendel’s law of dominance, based on Gregor Mendel’s observations that when two purebred individuals with different forms of the same trait are mated, only one of the two forms appears in the first generation of offspring. Mendel called the apparent form dominant and the suppressed form recessive.

Capillary(毛细血管)

Tiny blood vessels able to branch through the body and deliver oxygen and nutrients to every cell.

Carbon(碳)

The central element of life. Carbon has the ability to form bonds with up to four other elements or molecules at the same time.

carrying capacity(容纳生物的最高容量)

The maximum number of individuals in a population that can be sustained in a given environment. As populations become increasingly concentrated, competition for food and space, predation, and disease all determine carrying capacity.

Cartilage(软骨)

A firm but flexible substance, found in regions of vertebrate skeletons, such as the ribs, that need to bend.

Cell(细胞)

The smallest unit of life, consisting of a solution of organic molecules enclosed by a plasma membrane.

cell cycle(细胞周期) ：有丝分裂：间-前-中-后-末(Inter-pro-meta-ana-telo)

A process in which cells reproduce. First the cell replicates its DNA and then divides into two daughter cells. The two main phases of the cell cycle are interphase and mitosis.

cell membrane(细胞膜)

The phospholipid bilayer that surrounds all cells, regulating the passage of molecules in and out of the cell.

cellular respiration(细胞呼吸)

The process in which the cell burns glucose to create ATP with the aid of oxygen. Cells have two different methods of turning food into usable fuel: aerobic respiration and anaerobic respiration.

cell theory(细胞学说)

The doctrine that every living organism is composed of cells and that all cells come only from other preexisting cells.

cell wall(细胞壁)

A rigid structure that surrounds the outer membrane of some cells and helps maintain their shape. In plants the cell wall contains cellulose; in fungi it contains chitin; in prokaryotes it typically contains peptidoglycan.

Cellulose(葡萄糖)

A complex carbohydrate that constitutes the cell walls of plants and protist molds.

central nervous system (CNS/中枢神经系统)

The brain and the spinal cord. The CNS acts as the central command center of the body. Mostly made up of interneurons.

Centriole(中心粒)：中心体的主要结构。在细胞分裂前期向细胞两极移动，当中有纺缍丝相连

A structure in the cell that plays an important role in cell replication. During prophase, the centrioles migrate to the poles of the cell and form the mitotic spindle, which allows the chromosomes to be organized and split when the cell divides.

Cerebellum(小脑)

Part of the brain. Makes sure that movements are coordinated and balanced.

Cerebrum(大脑)

Part of the brain. Controls all voluntary movement, sensory perception, speech, memory, and creative thought.

independent assortment(单独分类)

Mendel’s conclusion that during gamete formation, the segregation of one pair of genes has no influence over the segregation of another pair of hereditary units. Two different traits will thus be inherited independently of each other. This law holds true, except for linked genes. It is often called Mendel’s second law.

inheritance of acquired traits(获得性状遗传)

A crucial, and incorrect, aspect of Lamarck’s theory of evolution. Lamarck believed that the traits a parent acquired during its lifetime would be passed on to its offspring.

Instincts(本能)

Behavior that is hardwired into the brain of an organism; behavior that does not have to be learned.

Insulin(胰岛素)

Hormone secreted by the pancreas that reduces blood sugar levels. A lack of insulin can result in diabetes.

Interphase(间期)

The phase of the eukaryotic cell cycle in which the cell prepares for division, primarily by replicating its DNA. After interphase, the cell enters mitosis.

intertidal zone(潮间带)：涨潮线与落潮线中间之地区

The most shallow zone in a marine habitat. Periodically dry or wet with the changing tides. Algae, sponges, mollusks, starfish, and crabs inhabit this zone. Also called the littoral zone.

Ion(离子)

An atom or molecule that has lost or gained an electron and consequently has a positive or negative charge.

Isotonic(同渗压的)

A situation in which the concentration of solutes in a solution is equivalent to what it contains. There is no concentration gradient in isotonic solutions and no net flow of solutes or water.