22 How a Flower Gets Its Color-Mid

How a Flower Gets Its Color FOCUS Question How do plants get their traits?

花的颜色是如何形成的?

Growing a Garden Suppose you have a garden full of bright red marigolds. One day, you spot a single white marigold among all the red ones. The two colors look nice together, and you think a mix of red and white flowers would make a beautiful garden. You know that each flower will produce seeds, which can grow into new marigolds. To get more white flowers, you decide to plant the seeds that grow inside the white flower. But you soon discover that your simple plan wasn't so simple.

假设你有一个满是鲜红色万寿菊的花园。 有一天，你在一片红色的金盏花中发现了一朵白色的金盏花。 这两种颜色搭配在一起很好看，你认为红白相间的花会构成一个美丽的花园。 你知道每一朵花都会产生种子，这些种子可以长成新的金盏花。 为了得到更多的白花，你决定种植生长在白花内部的种子。 但你很快就会发现，你的简单计划并没有那么简单。

What Are Traits? Flower color is one way to describe marigolds. It is a trait— a characteristic of a living thing. Other traits of marigolds include spiky leaves and many small stems. They grow to a height of about 30 centimeters (12 in.). All plants have traits. For example, oak trees have broad leaves and a wooden trunk and grow to a height of about 25 meters (82 ft.). All marigolds have similar traits to one another. However, each marigold may have slightly different traits. One marigold may have white flowers. Another may have red flowers. Every cell in every living thing has a set of instructions for growing its traits. The instructions are found inside a chemical code called DNA.

什么是特质?花的颜色是形容万寿菊的一种方式。 这是一种特征，一种生物的特征。 金盏花的其他特征包括带刺的叶子和许多小茎。 它们能长到30厘米(12英寸)高。 所有的植物都有性状。例如，橡树有宽阔的叶子和木制的树干，可以长到大约25米(82英尺)的高度。 所有的金盏花都有相似的特征。 然而，每个金盏花可能有略微不同的特征。 一株金盏花可能开白色的花。 另一种可能有红色的花。 每一种生物的每一个细胞都有一套生长特性的指令。 这些指令存在于一种叫做DNA的化学密码中。

Living things get DNA from each parent. You got half of your DNA from your mother and half from your father. The two sets of DNA then combined, and you received some traits from each parent. Every living thing's traits are inherited, which means they come from its parents' DNA. Plants combine DNA when pollen from one plant reaches the flower of another plant. The flower makes seeds, which grow into new plants. The seeds from your white marigold got half of their DNA from the white flower and half from the pollen of one of the red marigolds. What color will the new flowers be? Do You Know? Some traits are a blend of both parents' traits. Other traits are affected by the environment. For example, an oak tree in a dry area will not grow very tall, even if it has a "tall" trait in its DNA.

生物从双亲那里获得DNA。 你的DNA一半来自你母亲，一半来自你父亲。 然后这两组DNA结合在一起，你从父母双方都获得了一些特征。 每一种生物的特征都是遗传的，这意味着它们来自父母的DNA。 当一种植物的花粉到达另一种植物的花朵时，植物会结合DNA。 花产生种子，种子长成新的植物。 你的白色万寿菊种子的DNA一半来自白色花朵另一半来自一棵红色万寿菊的花粉。 新开的花是什么颜色? 你知道吗?有些性格是父母双方性格的混合。 其他性状则受环境影响。 例如，干旱地区的橡树不会长得很高，即使它的DNA中有“高”的特征。

Not So Simple You plant the seeds from the white marigold in a big pot, and eight plants spring up. You predicted that half would have red flowers and half would have white flowers. Or maybe all eight flowers would be pink since red and white make pink. When the flowers open, you can't believe it. All eight flowers are red! Instead of planting the new flowers in the garden, you leave them in the pot. In time, they produce new seeds, but you ignore them. Their flowers will just be red anyway, right?

你把白色金盏花的种子种在一个大花盆里，就会长出八株植物。 你预测一半会开红花，一半会开白花。 或者八朵花都是粉红色的，因为红色和白色是粉红色的。 当花儿开放的时候，你简直不敢相信。 八朵花都是红色的!你不是把新花种在花园里，而是把它们留在花盆里。 随着时间的推移，它们产生了新的种子，但你忽略了它们。 反正他们的花都是红色的，对吧?

A few months later, you check the pot of marigolds again. The eight red plants have wilted, but there are twelve new plants. Nine are red and three are white! What's going on? You still want white flowers, so you carefully transfer pollen from the stamen of one white flower onto the pistil of another white flower. Soon, seeds develop from the two parents that had white flowers. When these new plants grow. all the flowers are white. You're happy, but this makes no sense! Or does it?

几个月后，你再次检查了那盆万寿菊。 八株红色的植物已经枯萎了，但是有十二株新的植物。 九个是红色的，三个是白色的!这是怎么呢 你仍然想要白色的花，所以你小心地将花粉从一朵白花的雄蕊转移到另一朵白花的雌蕊上。 很快，开白花的双亲就会结出种子。 当这些新植物生长时。 所有的花都是白色的。 你很开心，但这毫无意义!真的是这样吗?