Conclusion the extra small chromosome is part of the chromosome Y.

结论：额外小染色体来源于Y染色体。

youdao

Just get a smaller size. - This is the smallest size, it's the extra small.

换小码呗~ -这就是最小号了…而且这是特小号。

youdao

The design and main feature of semiautomatic multi-use grinder for miniature and extra small bearings is introduced.

介绍了半自动微小型轴承多用磨床的结构设计及其特点。

youdao

There is a small hole in the side to drain out extra moisture and keep from drowning the plants.

VOA: special.2011.06.14

First we have the "Pilot of some small night-founder'd Skiff," and the pilot stands ab extra, from outside, in the simile.

首先我们有这句“迷茫深夜中，轻舟的导航人“,并且这个导航人在明喻中，体现为从诗句之外向内眺望。

耶鲁公开课 - 弥尔顿课程节选

They look like an extra-large version of the World War Two jeep, but enclosed, with small blast-proof windows, a protected machine gun position on top and a variety of high-tech gear inside and out.

VOA: standard.2009.11.02

In any case, the difference between 2.5% and 3% may only deliver a small extra return.

BBC: Energy switching: Why the customer inertia?

Investors who choose to take extra risks in small-cap and value stocks should expect to earn higher returns.

FORBES: Beat the Market with Small-Cap Value Stocks

So investors interested in the potential for extra dynamism in small cap stocks might want to consider that route.

FORBES: Small Cap Stocks And ETF To Milk The January Effect