SAT2生物考試專業(yè)詞匯：A.

　　SAT2考試是SAT subject test的通常說法，SAT2考試有別于SAT1，它是一種專項考試，考察學生某一科目的能力。下面澳際小編搜集整理了SAT2生物考試專業(yè)詞匯中以字母A打頭的詞匯，希望能夠幫助大家更好地備考SAT2生物考試。

　　autonomic nervous system(自主神經(jīng)系統(tǒng))

　　The involuntary half of the peripheral nervous system. The autonomic nervous system is in two antagonistic parts: the sympathetic(交感神經(jīng)的) and parasympathetic(副交感神經(jīng)的) nervous systems. Their interactions control smooth and cardiac muscle, glands, and organs and processes such as heartbeat, the movements of the digestive tract, and the contraction of the bladder.

　　Autosome(正染色體，非性染色體)

　　Any chromosome that is not a sex chromosome. Humans have 44 autosomes, in 22 homologous pairs. The two sex chromosomes are the twenty-third pair of chromosomes.

　　Autotroph(自養(yǎng)生物)

　　An organism that can produce the organic molecules and energy necessary for life through the processes of photosynthesis or chemosynthesis. Autotrophs do not rely on other organisms for food. In a food web, autotrophs are producers.

　　Auxin(茁長素) ：一種植物激素，刺激細胞伸長

　　One in a class of plant hormones that stimulates (among other things) cell elongation, secondary tissue growth, and fruit development.

　　active site(酶活性部分)

　　The part of an enzyme that interacts with, or binds to, a substrate.

　　active transport(主動運輸)

　　The movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration. Because active transport involves moving the molecule against the natural flow of the concentration gradient, the process requires energy.

　　adaptive radiation(適應輻射) ：同起源生物類群演化成多種不同類型的后代，以適應不同環(huán)境的現(xiàn)象

　　The evolutionary process by which ancestral forms of an organism are diversified through adaptation to new environments.

　　adenosine triphosphate (ATP/腺苷三磷酸)

　　The energy storage molecule for the cell. ATP consists of an adenosine molecule bonded to three phosphate groups. Each phosphate bond contains energy; by breaking these bonds, the cell can get the energy it needs for chemical reactions. Cells build ATP during cell respiration, using the raw material of glucose.

　　adrenal glands(腎上腺)

　　Two glands, the adrenal cortex(腎上腺皮質(zhì)，分泌可的松【cortisone】，醛固酮【aldosteron，用于調(diào)節(jié)滲透，控制鈉，鉀離子的重新吸收】等激素) and adrenal medulla(腎上腺髓質(zhì)，分泌腎上腺素【adrenaline】), located on the kidney.

　　aerobic respiration(有氧呼吸)

　　A form of cell respiration requiring oxygen (as opposed to anaerobic respiration, which does not need oxygen). Aerobic respiration is much more ficient than anaerobic respiration; it produces 36 ATP for every molecule of glucose. Aerobic respiration proceeds in three stages: glycolysis(糖酵解), the Krebs cycle(三羧酸循環(huán)), and the electron transport chain(電子傳遞鏈).

　　allantois(尿囊): 胚胎時期積存排泄廢物、氣體交換的場所

　　The extraembryonic membrane of birds, reptiles, and mammals that serves as an area of gaseous exchange and as a site for the storage of noxious excretion products.

　　allele(等位基因):位于一對同源染色體的相同位置上控制某一性狀的不同形態(tài)的基因

　　A specific form or possible version of a gene having multiple versions. Alleles may be dominant or recessive.

　　allelic frequency(等位基因頻率)

　　The frequency with which a particular allele for a certain characteristic appears among all possible alleles for that characteristic in a population.

　　alternation of generations(世代交替)：一種生物(種)，生殖方式不同的世代，周期的、或不規(guī)則的交替(苔蘚植物和蕨類植物具有此特征)

　　The fluctuation between the diploid (sporophyte) and haploid (gametophyte) life stages that occur in plants.

　　alveolus(肺泡)

　　An air sac in the lung, the site of respiratory exchange.

　　amino acid(氨基酸)

　　The monomer of a protein. A central carbon attached to an amino group (–NH2), a carboxyl group (–COOH), and a hydrogen atom (–H). The fourth group is variable and dines the amino acid’s chemical identity.

　　Amnion(羊膜) ：位于最內(nèi)側(cè)直接覆蓄胚體的膜

　　The extraembryonic membrane in birds, reptiles, and mammals that surrounds the embryo, forming an amniotic sac.

　　anaerobic respiration(無氧呼吸)

　　A form of cell respiration that does not use oxygen (as opposed to aerobic cell respiration). Anaerobic respiration is less ficient than the aerobic variety and produces just 2 ATP per molecule of glucose. Anaerobic respiration has two stages: glycolysis and fermentation(發(fā)酵).

　　analogous trait (相似特征)：來源于相同祖先，與其他生物種功能、形態(tài)上相似的結(jié)構(gòu)

　　A trait that is morphologically and functionally similar to that of a different species but that arose from a distinct, ancestral condition.

　　anaphase (分裂后期)

　　The stage of mitosis in which sister chromosomes are separated and pulled to opposite ends of the cell by microtubules; the fourth stage of the first meiotic division (meiosis I), during which maternal and paternal homologous pairs are separated on microtubules; the fourth stage of the second meiotic division (meiosis II), during which either maternal or paternal sister chromatids are separated on microtubules.

　　androgen(雄性激素)

　　A male sex hormone. (e.g. testosterone【睪酮】)

　　Angiosperm(被子植物)

　　A vascular flowering plant in which seeds are enclosed inside protective ovaries, such as fruit or flowers. Angiosperms can be monocots(單子葉) or dicots(雙子葉).

　　Anther(花粉囊，花藥)

　　Pollen-producing structure at the top of the stamen, the male reproductive organ of flowers.

　　abiotic (無生命的)

　　Nonliving materials in the environment—such as elements, sunlight, and soil—that influence and are influenced by living (biotic) entities on the planet.

　　Acetylcholine(乙酰膽素): 運動神經(jīng)釋于一種化學物質(zhì),與其接受體結(jié)合后，能產(chǎn)生足夠的電位變化來引起肌肉運動

　　A neurotransmitter released from the axons of nerve cells to excite an action potential or trigger a muscle to contract.

　　active immunity(主動免疫)

　　Protective immunity to a disease in which the individual produces antibodies as a result of previous exposures to the antigen.

　　Acids(酸)

　　Hydrogen ion (H+) donors. Acids are very important in the chemical reactions of life because they are highly reactive. Acids have pH values below 7. They are the opposite of bases.

　　actin (肌動蛋白)

　　Protein filaments that, along with myosin, allow muscles to contract.

　　Anticodon(反密碼子) ：位于tRNA上，和mRNA的密碼子相反配對

　　The sequence of three nucleotides on tRNA that pairs with a codon of mRNA at the A site of a ribosome during translation.

　　Antigen(抗原)

　　A protein coat on the surface of red blood cells; a red blood cell may have a protein coat of type A, B, or AB. If the cell has no antigens, it is called type O. The presence of a foreign antigen in a body will cause blood to clot.

　　Aorta(大動脈)

　　The largest artery in the body; carries oxygenated blood from the lt ventricle of the heart.

　　aphotic zone(無光帶)

　　Literally, zone without light. The aphotic zone is part of the marine pelagic zone and begins 600 feet below the surface of the ocean. Only chemosynthetic organisms, scavengers, and predators are able to survive in this habitat.

　　Appendage(附屬肢體)

　　A structure that extends from the trunk of an organism and is capable of active movements.

　　Artery(動脈)

　　Vessel that carries blood away from the heart and has thick, elastic, muscular walls that can dilate or contract to control blood pressure within the vessels. Blood in arteries is oxygenated, with the exception of the blood in the pulmonary artery(肺動脈，把心臟中的血輸送到肺部的動脈).

　　以上便是澳際小編為大家整理的SAT2生物考試專業(yè)詞匯中以字母A打頭的詞匯的相關(guān)介紹，希望對大家有所幫助。更多SAT考試相關(guān)資料盡在澳際教育網(wǎng)SAT考試頻道，澳際小編祝大家都能取得理想的SAT2生物考試成績!