时间:2019-02-24 作者:英语课 分类:英语听力文摘 English Digest


英语课

  Why Clones Aren’t Copies

克隆是英文"clone"或"cloning"的音译,而英文"clone"则起源于希腊文"Klone",原意是指以幼苗或嫩枝插条,以无性繁殖或营养繁殖的方式培育植物,如扦插和嫁接。在大陆译为“无性繁殖”在台湾与港澳一般意译为复制或转殖或群殖。 中文也有更加确切的词表达克隆,“无性繁殖”、“无性系化”以及“纯系化”。克隆是指生物体通过体细胞进行的无性繁殖,以及由无性繁殖形成的基因型完全相同的后代个体组成的种群。通常是利用生物技术由无性生殖产生与原个体有完全相同基因组织后代的过程。


  Last time we were talking about how cloned animals, to some people’s surprise, aren’t just copies of their parent animals. In cloned pigs, for example, some come out bristly-haired, some smooth; some are shy, others aggressive.

How can animals share all the same genes 2 and yet be so different?

Geneticists aren’t sure yet. One possibility is that chemical conditions inside the uterus affect how the fetus 3 develops. But there’s also gene 1 expression to consider. Gene expression refers to which genes are turned on and which are turned off.

Every gene in your body comes in duplicate. You get one from your mother and one from your father. Let’s simplify the situation and pretend there’s just one gene that gives you your sparkling personality.

For example, let’s say your mother was a jewel and that your dad was a crank.

In this instance, presuming you’re an angel, we can imagine that the “personality gene” your father gave you is in the “off” position, while the personality gene your mother gave you is in the “on” position. Would your clone have your same personality?

We don’t know, because we don’t know what position that switch will be in. In reality, there are many, many switches, leading to many possible combinations. A clone is a duplication of the genes, but not of the gene expression.

In other words, a clone could share genes and still look and act differently. They aren’t carbon copies–they are separate organisms all to themselves.



n.遗传因子,基因
  • A single gene may have many effects.单一基因可能具有很多种效应。
  • The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。
n.基因( gene的名词复数 )
  • You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因,所以能够活得很长。 来自《简明英汉词典》
  • Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪
n.胎,胎儿
  • In the fetus,blood cells are formed in different sites at different ages.胎儿的血细胞在不同时期生成在不同的部位。
  • No one knows why a fetus is not automatically rejected by the mother's immune system. 没有人知道为什么母亲的免疫系统不会自动排斥胎儿。
学英语单词
abundance of commodity supplies
acetomercurihydroxypropane
agu
anemone storonifera maxim.
atomic explosion evidence
audit strategy
biatrial
binary notation
bloodened
branch controller
brassica nigras
broken hyperlink
Bulgarian monetary unit
bursa(equivalent)lymphocyte
can end press
Cephalomappa
chemoimmunologies
chin breadth
cockapoo
coldheartedness
common-base transistor
compounding effect
continu
coprozoic parasite
dental-records
Digitaria setigera
dolichoplatycephalus
double acting rotary engine
e-learning
east-meets-west
eddy available potential energy
error deformation string
facies interna
figure of merit (g/t) reliability increase
flavorx
floodmarks
frame grid
free-boot
front-wheel mechanism
frozen pack storage
genus Sphaerocarpos
gib boom
glaciations
Glinus lotoides
Glyped
green's
griege
Gurnee
hand gas grenade
he'bert
heavy hydraulic press
hospital ships
huz
intersectant
ITSO
job control table
land liable to flood
lever movement
local mode
loretto
Metaquine
monodical
mukumbi
new life
noduli valvularum semilunarium
nonbusiness itemized deductions
noncyclotomic
Papa, Holm of
Pelly Mts.
phase generator
picosulfate sodium
pituitary gonadotropic hormone
post-auditings
primary power source
protester
rafiah
remote control board
resource centre
rhizoma
rigid surface planing
roller with trunnions
Rosetown
sail one's own boat
Scaferlati
sericitizations
set shackle
sige
six-miler
stop-watch cycle time
storgae cell
streamlined pump
Success, L.
supercritical gas
swaziland monetary units
synergism
tangle with sb
Teach, Edward
tetradrachms
the left
thyris alex
wriggled out of
zinc thymotate