Alevel生物屬于科學(xué)類課程，同學(xué)們在學(xué)習(xí)科學(xué)類課程時總是繞不開“寫報告”的一大難關(guān)，報告可以說是論文的plus版，不僅需要大家具有堅實的學(xué)科理論基礎(chǔ)，還有具有一定的實踐分析能力。為幫助大家緩解Alevel生物寫作時的痛苦，我們留求藝留學(xué)為大家收集整理了一系列高分筆記和Essay寫作素材，可在本站搜索取用。

For a species to survive, it must reproduce. However, the population is limited by environmental factors and so remains more or less constant over time.

一個物種要想生存，就必須進行繁殖。然而，種群受到環(huán)境因素的限制，因此隨著時間的推移或多或少地保持不變。

There is competition between individuals of the same species (intraspecific competition) or between members of different species (interspecific competition) for resources.

同一物種的個體之間（種內(nèi)競爭）或不同物種的成員之間（種間競爭）存在著資源的競爭。

Since there is variation within a population, some individuals are less well adapted to a particular environment. The less well adapted are 'weeded out' as the selection acts on the phenotype of the individual.

由于種群內(nèi)部存在差異，一些個體對特定環(huán)境的適應(yīng)性較差。由于選擇作用于個體的表型，適應(yīng)性較差的個體被 "淘汰 "了。

These individuals fail to reproduce or die, the more successful ones reproduce and pass on their genes to the next generation.

這些個體不能繁殖或死亡，較成功的個體則繁殖并將其基因傳給下一代。

Note: Adaptations are environment-specific; an advantageous characteristic can become disadvantageous if the environment changes in a particular way.

The change in adaptation that occurs is called evolution.

所發(fā)生的適應(yīng)性變化被稱為進化。

There are three types of selection that occur in nature

在自然界中有三種類型的選擇:

Stabilizing selection. 穩(wěn)定化選擇

Directional selection. 方向性選擇

Disruptive selection. 破壞性選擇

In each case we will use the illustration of a population of mammals and the characteristic being selected for or against is fur length.

在每一種情況下，我們都將使用哺乳動物種群的例子，被選擇的特征是毛發(fā)長度。

In each situation, the population is normally distributed - there are a few individuals that have very short or very long fur length but most have an intermediate fur length.

在每種情況下，種群都是正態(tài)分布的--有幾個個體的毛發(fā)長度非常短或非常長，但大多數(shù)個體的毛發(fā)長度處于中間水平。

【微語】跨出國門，人生開始新的旅程。一路上，難免會有荊棘風(fēng)暴與雷鳴。相信你會以堅實的腳步，不懈地向成功邁進。