【英语时差8,16】动物界的染色体有何不同？2

 But what’s true for mammals isn’t always true for the rest of the animal kingdom. The sex of baby birds is also determined¹ by two different sex chromosomes², but in birds, it’s the male that has two of the same-shaped sex chromosomes and the female that has two different sex chromosomes. A lot of reptiles³, including crocodiles and some turtles don’t even have sex chromosomes. The sex of these animals is determined by the temperature of the eggs before they hatch. And in some species of fish, female adults can turn into males if there aren’t enough males in the population, while in others males turn into females.

1 determined   

adj.坚定的；有决心的

参考例句：

• I have determined on going to Tibet after graduation.我已决定毕业后去西藏。
• He determined to view the rooms behind the office.他决定查看一下办公室后面的房间。

2 chromosomes   

n.染色体( chromosome的名词复数 )

参考例句：

• Chromosomes also determine the sex of animals. 染色体也决定动物的性别。 来自《简明英汉词典》
• Each of four chromosomes divide longitudinally. 四种染色体的每一种都沿着纵向分裂。 来自《现代汉英综合大词典》

3 reptiles   

n.爬行动物，爬虫( reptile的名词复数 )

参考例句：

• Snakes and crocodiles are both reptiles. 蛇和鳄鱼都是爬行动物。 来自《简明英汉词典》
• Birds, reptiles and insects come from eggs. 鸟类、爬虫及昆虫是卵生的。 来自《现代汉英综合大词典》