首页
登录
职称英语
[originaltext] Human population near the equator have evolved dark skin over
[originaltext] Human population near the equator have evolved dark skin over
游客
2025-02-06
28
管理
问题
Human population near the equator have evolved dark skin over many generations because of exposure to the fiercest rays of the sun. A similar phenomenon has also occurred in other parts of the animal kingdom. The African grass mouse is a good example. Most mice are nocturnal, but the African grass mouse is active during daylight hours. This means that it spends its days searching for food in the semi-dry bush in squired habitats of eastern and southern Africa. Its furry stripe’s like a chipmunk’s, which helps it blend in with its environment.
Because it spends a lot of time in the intense tropical sun, the grass mouse has also evolved two separate safeguards against the sun’s ultraviolet radiation. First, like the population of humans in this region of the world, the skin of the grass mouse contains lots of melanin, or dark pigment. Second and quite unusual, this mouse has a layer of melanin pigmented tissue between its skull and skin. This unique cap provides an extra measure of protection for the grass mouse and three other types of African mouse, like rodents that are active during the day. The only other species scientists have identified with the same sort of skull of that occasion is the white camp-making bat of the Central American tropic. Although these bats sleep during the day, they do so curled up with their head exposed to the sun.
选项
A、It has a flattened shape
B、It has an extra layer of pigmented tissue
C、It has a furry covering
D、It has a large cranial cavity
答案
B
解析
What is unusual about the head of African grass-mouse?
转载请注明原文地址:https://tihaiku.com/zcyy/3945777.html
相关试题推荐
[originaltext]Humanpopulationneartheequatorhaveevolveddarkskinover
[originaltext]Humanpopulationneartheequatorhaveevolveddarkskinover
[originaltext]Humanpopulationneartheequatorhaveevolveddarkskinover
[img]2014m3s/ct_etoefm_etoefspeakc_0088_20138[/img][originaltext]Usingpointsa
[img]2014m3s/ct_etoefm_etoefspeakb_0356_20138[/img][originaltext]Theprofessor
[img]2014m3s/ct_etoefm_etoefspeaka_0355_20138[/img][originaltext]Thestudentex
[img]2014m3s/ct_etoefm_etoefspeaka_0174_20138[/img][originaltext]Somepeopleli
[img]2014m3s/ct_etoefm_etoefspeakc_0538_20138[/img][originaltext]Usingthepoin
[img]2014m3s/ct_etoefm_etoefspeaka_0264_20138[/img][originaltext]Somepeoplepr
[img]2014m3s/ct_etoefm_etoefspeakb_0266_20138[/img][originaltext]Theprofessor
随机试题
MillionsofAmericanstakefishoilsupplementstoimprovetheirhealth.Buthow
Thereisvirtuallynolimittohowonecanservecommunityinterests,froms
Beta可用以测度()。A.公司特殊的风险 B.可分散化的风险 C.市场风险
药物产生不良反应的剂量是()A.中毒量 B.LD C.无效剂量 D.
缺铁性贫血缺铁性贫血期为A.叶酸和维生素B缺乏 B.贮存铁下降,早期出现血清铁
教师组织学生开展“古诗词中‘鸟’的意象”主题活动,并列举了以下例子,请学生找出意
新生儿生理性体重下降一般不超过A.2% B.4% C.7% D.9% E
患者,女,40岁,慢性肾小球肾炎病史10年。因反复发作不愈,影响生活和工作,患者
我国《证券法》规定,证券投资者保护基金由()缴纳的资金及其他依法筹集的资金组成。
【背景资料】 某项目经理部中标某城市道路工程A标段,中标价为3000万元。项目
最新回复
(
0
)