This closeup view of a lily
flower
shows the fine detail of this structure. Why are flowers so colorful? What is the purpose of all the parts? They were one of the last
adaptations
of the plant
, suggesting immense evolutionary significance.
::对百合花的这种近视显示了这个结构的精细细节。为什么花朵如此丰富多彩?所有部分的目的是什么?它们是植物最后的调整之一,表明它具有巨大的进化意义。
Flowering Plants
::流动工厂
Angiosperms
, or flowering
seed
plants, form seeds in
ovaries
. As the seeds develop, the ovaries may develop into
fruits
. Flowers attract
pollinators
, and fruits encourage
to disperse the seeds.
::血管增生机,或开花种子植物,在卵巢中形成种子。 随着种子的生长,卵巢可能发展成水果。 花朵吸引授粉者,水果鼓励种子散落。
Parts of a Flower
::花花的一部分
A flower consists of male and female reproductive structures. The main parts of a flower are shown in
Figure
. They include the
stamen
,
pistil
,
petals
, and
sepals
.
::花朵由男性和女性生殖结构组成,花朵的主要部分见图6。 花朵主要部分包括花冠、活塞、花瓣和树皮。
The
stamen
is the male reproductive structure of a flower. It consists of a stalk-like filament that ends in an
anther
. The anther contains
pollen
sacs, in which
occurs and pollen grains form. The filament raises the anther up high so its
pollen
will be more likely to blow in the wind or be picked up by an animal pollinator.
::丝绸花是花朵的男性生殖结构。 它由一条尾巴般的丝状丝组成, 其端端端在一个生虫。 蚂蚁含有花粉囊和花粉颗粒。 丝绸将花朵抬高, 使其花粉更有可能在风中爆炸或被动物授粉者捡起。
The
pistil
is the female reproductive structure of a flower. It consists of a
stigma
,
style
, and
ovary
. The stigma is raised and sticky to help it catch pollen. The style supports the stigma and connects it to the ovary, which contains the
egg
.
Petals
attract pollinators to the flower. Petals are often brightly colored so pollinators will notice them.
::活塞是花朵的雌性生殖结构,由污名、风格和卵巢组成。 污名被提升并粘贴, 以帮助它捕捉花粉。 风格支持污名并将其与卵子中的卵子连接起来。 金属吸引授粉者到花朵中。 金属往往颜色亮亮, 授粉者会注意到它们。
Sepals
protect the developing flower while it is still a bud. Sepals are usually green, which camouflages the bud from possible consumers.
::石块保护正在生长的花朵,而花朵却仍然是鲜花。 石块通常是绿色的,它掩盖了可能消费者的花朵。
A flower includes both male and female reproductive structures.
::花朵包括男性和女性的生殖结构。
Flowers and Pollinators
::花粉和花粉
Many flowers have bright colors, strong scents, and sweet
nectar
to attract animal pollinators. They may attract
,
,
mammals
, and even
. While visiting a flower, a pollinator picks up pollen from the anthers. When the pollinator visits the next flower, some of the pollen brushes off on the stigma. This allows
cross-pollination
, which increases
genetic diversity
.
::许多花朵有明亮的颜色、强烈的气味和甜甜的花蜜,以吸引动物授粉者。它们可能会吸引,甚至吸引,哺乳动物,甚至吸引。在参观花朵时,授粉者会从肛门中采集花粉。当授粉者到下一朵花时,一些花粉会冲淡污名。这让跨极现象增加遗传多样性。
Other Characteristics of Flowering Plants
::流动工厂的其他特点
Although flowers and their components are the major innovations of angiosperms, they are not the only ones. Angiosperms also have more efficient
. Additionally, in many flowering plants the ovaries ripen into fruits. Fruits are often brightly colored, so animals are likely to see and eat them and disperse their seeds (see
Figure
).
::虽然花及其组成部分是血管动物的主要创新,但并非只有它们,血管动物也更有效率。此外,在许多开花的植物中,卵巢成熟成水果。 水果的颜色往往亮亮,因此动物可能看到和吃它们并散布种子(见图 )。
Brightly colored fruits attract animals that may disperse their seeds. It’s hard to miss the bright red apples on these trees.
::明亮的果实吸引了可能撒出种子的动物。 很难错过这些树上明亮的红苹果。
Evolution of Flowering Plants
::流动工厂的演变
Flowering plants are thought to have evolved at least 200 million years ago from
gymnosperms
like Gnetae. The earliest known
of flowering plants are about 125 million years old. The fossil flowers have male and female reproductive
organs
but no petals or sepals.
::据认为,至少2亿年前,花卉植物已经从像Gnetae这样的体操中演变而来。 最早已知的开花植物有大约1.25亿年的历史。 这些化石花有男性和女性生殖器官,但没有花瓣或花瓣。
Scientists think that the earliest flowers attracted insects and other animals, which spread pollen from flower to flower. This greatly increased the efficiency of
over wind-spread pollen, which might or might not actually land on another flower. To take better advantage of this “animal
labor
,” plants evolved traits such as brightly colored petals to attract pollinators. In exchange for
pollination
, flowers gave the pollinators nectar.
::科学家们认为,最早的花朵吸引了昆虫和其他动物,它们把花粉从花朵传到花朵。 这大大提高了风吹花粉的效率,而风吹花粉实际上可能降落在另一朵花上,也可能不会实际降落在另一朵花上。 为了更好地利用这种“动物劳动 ” , 植物发展出一些特性,比如光彩的花瓣来吸引授粉者。 作为授粉的交换,花朵给授粉者点花。
Giving free nectar to any animal that happened to come along was not an efficient use of resources. Much of the pollen might be carried to flowers of different
and therefore wasted. As a result, many plants evolved ways to “hide” their nectar from all but very specific pollinators, which would be more likely to visit only flowers of the same species. For their part, animal pollinators co-evolved traits that allowed them to get to the hidden nectar. Two examples of this type of co-evolution are shown in
Figure
.
::向偶然出现的任何动物免费赠送花蜜并不是对资源的有效利用。 大部分花粉可能携带到不同的花朵上,从而浪费。 结果,许多植物从所有但非常具体的授粉者那里“隐藏”它们的花蜜,而这些花蜜更可能只访问同一物种的花卉。 而动物授粉者则共同产生一些特征,从而得以接触到隐藏的花蜜。图中显示了这种共同演化的两个例子。
The sphinx moth has a long narrow
proboscis
to reach nectar at the bottom of the tube-shaped flowers. The bat is active at night, so bright white, night-blooming flowers attract it. In each case, the flowering plant and its pollinator co-evolved to become better suited for their roles in the symbiotic relationship.
::斯芬克斯飞蛾有着长长的狭长刺青,可以到达管状花朵底部的花蜜。 蝙蝠在夜间活动,因此明亮的白色夜花会吸引它。 在每种情况下,花卉及其授粉器共同演变,更适合它们在共生关系中的角色。
Some of the most recent angiosperms to evolve are grasses. Humans started domesticating grasses such as wheat about 10,000 years ago. Why grasses? They have many large, edible seeds that contain a lot of nutritious stored
food
. They are also relatively easy to harvest. Since then, humans have helped shaped the evolution of grasses, as illustrated by the example in
Figure
. Grasses supply most of the food consumed by people worldwide. What other grass seeds do you eat?
::最新进化的血管增生素中有些是草。人类大约在一万年前开始饲养小麦等草。为什么是草?它们有许多大而可食用的种子,含有大量营养的储存食物。它们也相对容易收获。从那以后,人类帮助了草的演变,如图中的例子所示。草供应了全世界人们消费的大部分食物。你还吃什么其他草种?
The plant on the left, called teosinte, is the
ancestor
of modern, domesticated corn, shown on the right. An intermediate stage is pictured in the middle. How were humans able to change the plant so dramatically?
::左侧的植物,叫做teosinte,是现代、家养玉米的祖先,在右侧展示。中间的阶段在中间描绘。人类是如何如此显著地改变植物的呢?
Classification of Flowering Plants
::流动工厂分类
There are more than a quarter million species of flowering plants, and they show tremendous diversity. Nonetheless, almost all flowering plants fall into one of three major groups:
,
, or
magnolids
. The three groups differ in several ways. For example, monocot
embryos
form just one
cotyledon
, whereas eudicot and magnolid embryos form two cotyledons. The arrangement of their vascular tissues is also different. Examples of the three groups of flowering plants are given in
Table
.
::花生植物有超过25万种,它们表现出巨大的多样性。尽管如此,几乎所有花生植物都属于三大类之一: 或木兰。这三大类不同,例如,单体胚胎只形成一个共质胚胎,而尤迪科特和大型花生胚则形成两个共质。它们的血管组织安排也不同。表1列出了三种花生植物的例子。
Group
Sample Families
Sample Families
Monocots
Grasses
::草 草 草
Orchids
::兰花
Eudicots
Daisies
::代 代 代
Peas
::青豆
Magnolids
Magnolias
::木兰
Avocados
::草粉
Summary
::摘要
Most modern seed plants are angiosperms that produce seeds in the ovaries of flowers.
::大多数现代种子植物是血管,在花卵中产生种子。
Ovaries may develop into fruits.
::植物可以发展成水果。
Flowers attract pollinators and fruits are eaten by animals. Both traits aid the dispersal of seeds.
::鲜花吸引授粉者,水果被动物吃掉,这两种特性都有助于种子的散布。
Review
::回顾
Describe the male and female reproductive structures of flowers.
::描述花朵的男女生殖结构。
State how fruits help flowering plants reproduce.
::水果如何帮助开花植物繁殖。
Explain how flowering plants and their animal pollinators co-evolved.
::解释开花植物和它们的动物授粉者 是如何共同演变的
