植物a端为形态学上端,植物的b端为形态学下端.当植物正常生长时,a端将背地生长,b端将向地生长; 当...植物a端为形态学上端,植物的b端为形态学下端.当植物正常生长时,a端将背地生长,b端将向

植物a端为形态学上端,植物的b端为形态学下端.当植物正常生长时,a端将背地生长,b端将向地生长; 当...植物a端为形态学上端,植物的b端为形态学下端.当植物正常生长时,a端将背地生长,b端将向
植物a端为形态学上端,植物的b端为形态学下端.当植物正常生长时,a端将背地生长,b端将向地生长; 当...
植物a端为形态学上端,植物的b端为形态学下端.
当植物正常生长时,a端将背地生长,b端将向地生长;
当植物水平放置时,a端仍将背地生长,b端仍将向地生长.请问为什么?

植物a端为形态学上端,植物的b端为形态学下端.当植物正常生长时,a端将背地生长,b端将向地生长; 当...植物a端为形态学上端,植物的b端为形态学下端.当植物正常生长时,a端将背地生长,b端将向
由于重力作用
a、b端生长素都是下端多,上端少
而根对生长素比较敏感,过多反而抑制它生长,所以根上端生长较快,向下弯曲
茎下端多,促进生长,下端生长快,所以向上弯曲
体现了植物生长素的两重性
不懂继续问

我汗……
只有在平放的时候才会有背地和向地啊

当植物水平放置时，由于重力的作用，生长素沉积在植物靠地的一侧，靠近a端（茎部）的最适生长素浓度较高，即对生长素的敏感性低，因而a端靠地一侧的细胞生长较快,就表现为向上生长；

Kinds of Drop-shipping Businesses - Produce a Smart Decision When Choosing a Drop Shipper,Vibram five fingers shoes
Drop Shipper
It seems that everyone today has discovered a way to earn grea...

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Kinds of Drop-shipping Businesses - Produce a Smart Decision When Choosing a Drop Shipper,Vibram five fingers shoes
Drop Shipper
It seems that everyone today has discovered a way to earn great cash on-line or possibly a full-time living that will make the big business men of the outside world jealous. So, you've decided that it is to time for you to get caught up within the race and take your big slice of the pie too. (Why don't you? Even eighteen years old teenagers are doing it.) Determined to discover the journey of on-line success you scoured the web and saw a rather appealing term known as "Drop Shipping"; an easy way to start selling items on eBay or an on-line store without worrying about stocking or shipping,five finger, and today you are itching to attempt out. But i want to quit you here. Before you make the leap and begin drop-shipping using the first company you found on the internet, you need to have a minutes time to learn who this drop shipper really is.
Obviously you know by now what a drop shipper is, but the question you'll need answered is who the drop shipper is. Is he a manufacturer? Is he a wholesaler? Or possibly he a middle man? To comprehend who your drop shipper is, you need to understand the way the Supply Chain works.The Supply Chain starts with a Manufacturer - the person who produces the item from raw supplies. Let's envision there is a need for hiking boots in the city called Hikers Leading. A Manufacturer will notice that demand and begin manufacturing a large majority of hiking boots from raw supplies like leather, cloth, rubber etc. Now, since the Manufacturer is really caught up in finding raw material supplies for production and busy running his factory, he doesn't have enough time or cash to place up a store in Hikers Leading and sell his boots straight to the public himself. So he looks for a Wholesaler who will purchase his hiking boots in big volume bulk for, let's assume,five fingers, $50 an instance (1 case=12 pairs of shoes). This price will be the Manufacturer's Wholesale Price.
However,fivefingers vibram, this Wholesaler will not sell the hiking boots straight to Hiker Top's public either. He is really a Distributor who will distribute the hiking boots to several Retailers. He will be the individual who links the Retailer with Manufacture. This Distributor does company with one or numerous Retailers who have shoe shops in Hikers Leading city. A shoe store Retailer will purchase truck plenty of hiking boot instances in the Distributor (Wholesaler) for, let's assume once more,five fingers shoes, $100 an instance. The Distributor makes a profit of $50 per case.

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生物激素的作用！

一楼很正确！！答案详解见一楼！

高中生吧，一楼算是标答

一楼的答案 你参考下吧