首页
登录
职称英语
All mammals feed their young. Beluga whale mothers, for example, nurse their
All mammals feed their young. Beluga whale mothers, for example, nurse their
游客
2025-02-07
26
管理
问题
All mammals feed their young. Beluga whale mothers, for example, nurse their calves for some twenty months, until they are about to give birth again and their young are able to find their own food. The behavior of feeding of the young is built into the reproductive system. It is a nonelective part of parental care and the defining feature of a mammal, the most important thing that mammals-- whether marsupials, platypuses, spiny anteaters, or placental mammals -- have in common.
But not all animal parents, even those that tend their offspring to the point of hatching or birth, feed their young. Most egg-guarding fish do not, for the simple reason that their young are so much smaller than the parents and eat food that is also much smaller than the food eaten by adults. In reptiles, the crocodile mother protects her young after they have hatched and takes them down to the water, where they will find food, but she does not actually feed them. Few insects feed their young after hatching, but some make other arrangement, provisioning their cells and nests with caterpillars and spiders that they have paralyzed with their venom and stored in a state of suspended animation so that their larvae might have a supply of fresh food when they hatch.
For animals other than mammals, then, feeding is not intrinsic to parental care. Animals add it to their reproductive strategies to give them an edge in their lifelong quest for descendants. The most vulnerable moment in any animal’s life is when it first finds itself completely on its own, when it must forage and fend for itself. Feeding postpones that moment until a young animal has grown to such a size that it is better able to cope. Young that are fed by their parents become nutritionally independent at a much greater fraction of their full adult size. And in the meantime those young are shielded against the vagaries of fluctuating of difficult-to-find supplies. Once a species does take the step of feeding its young, the young become totally dependent on the extra effort. If both parents are removed, the young generally do no survive. [br] The word "provisioning" in line 13 is closest in meaning to
选项
A、supplying
B、preparing
C、building
D、expanding
答案
A
解析
转载请注明原文地址:http://tihaiku.com/zcyy/3947066.html
相关试题推荐
[img]2012q1/ct_etoefm_etoefspeakc_0346_20121[/img]Usingpointsandexamplesf
Allmammalsfeedtheiryoung.Belugawhalemothers,forexample,nursetheir
Allmammalsfeedtheiryoung.Belugawhalemothers,forexample,nursetheir
Allmammalsfeedtheiryoung.Belugawhalemothers,forexample,nursetheir
Allmammalsfeedtheiryoung.Belugawhalemothers,forexample,nursetheir
Allmammalsfeedtheiryoung.Belugawhalemothers,forexample,nursetheir
Allmammalsfeedtheiryoung.Belugawhalemothers,forexample,nursetheir
Allmammalsfeedtheiryoung.Belugawhalemothers,forexample,nursetheir
[img]2012q1/ct_etoefm_etoefspeakc_0119_20121[/img]Usingexamplesanddetails
"Thermoregulation"Mammalsandbirdsgenerallymaintainbodytemperaturewith
随机试题
WhydidHamptonhotelsdonatemoneytosupportcitizenefforts?[originaltext]
Forthispart,youareallowed30minutestowriteanessaycommentingononeof
Insportthesexesareseparate.Womenandmendonotrunorswiminthesam
道德产生于社会存在、发展的客观需求和人类自身追求完善的主观需求,它从社会生活中产
零星机具可按定额规定使用期限,由班组保管,丢失赔偿。()
《党章》强调,要不断提高党的创造力、凝聚力、战斗力,建设学习型、()、创新型的
患者,女性,53岁。患焦虑症3年,此次因心绞痛发作入院治疗,某日早餐吃烧饼时突然
从所给的选项中,选择最合适的填入问号处,使之呈现规律性: A.如上图所示 B
中国证监会可以对()等特殊行业上市公司的信息披露作出特别规定。A:娱乐 B:外
投资项目决策分析与评价的基本要求包括贯彻落实科学发展观、资料数据准确可靠和()
最新回复
(
0
)