时间:2019-01-08 作者:英语课 分类:Scientific American(三)月


英语课

This is Scientific American's 60-Second Science. I'm Cynthia Graber. This will just take a minute.


Mark Twain called it "the most delicious fruit known to men." He was talking about the cherimoya. If you never heard of it, there's good reason. It has a feature that has prevented it from becoming widely popular—numerous big seeds fill its sweet white flesh.


But now scientists in Spain and at the University of California, Davis have found the key to making the cherimoya and related fruits seedless. They published their research in the Proceedings 1 of the National Academy of Sciences.


It's generally tough to develop a seedless fruit—bananas and oranges are rare successes. Breeding for seedlessness usually fails to produce the fully 3 developed fruit consumers demand. But the scientists found a spontaneous mutation 4 that causes seedlessness in a cherimoya relative, the sugar apple. They compared its genome to that of a seedless mutant of a plant called Arabidopsis that's used in a lot of research.


In both cases, they found a deletion of one particular gene 2. The researchers say this is the first time a gene for seedlessness has been determined 5. If they can find a way to knock out that gene in the cherimoya, it could bring Mark Twain's favorite fruit, and many others, to a grocery store near you.


Thanks for the minute. For Scientific American's 60-Second Science, I'm Cynthia Graber.



n.进程,过程,议程;诉讼(程序);公报
  • He was released on bail pending committal proceedings. 他交保获释正在候审。
  • to initiate legal proceedings against sb 对某人提起诉讼
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。
adv.完全地,全部地,彻底地;充分地
  • The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气,然后全部呼出。
  • They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。
n.变化,变异,转变
  • People who have this mutation need less sleep than others.有这种突变的人需要的睡眠比其他人少。
  • So far the discussion has centered entirely around mutation in the strict sense.到目前为止,严格来讲,讨论完全集中于围绕突变问题上。
adj.坚定的;有决心的
  • 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。
标签: sss 托福素材
学英语单词
abrogation of rights
Aethoxide
Akkad
AM
average length of haul
basal metabolic rate
basilicon Ointment
bioregionalism
bottom side tank
bureaucratic inertia
byte instruction
Canadian Prairies
cannon cracker
chirurgeonly
chord deflection angle
collision damping
content-rich
data ingestion
deck for
dibenzyl sulfide
direct-drive
epidermocytic spine
extra-cheese
federal housing act
file set
flowing liquor
full-mouthed
georgeite
GM_relative-clauses-defining-and-non-defining
gold potassium iodide
greenlick
Gstadt am Chiemsee
hand and spring
hot money
hot-pressed gold
htm
hylo-
I'll be hanged if...
ignace jan paderewskis
imaginarily
isolotto
kakortokite
Lateral archegonia
lateral tomogram of maxillae
linear programming
lobolas
lower lateral bracing
marrok
multiple engine build-up list (mebul)
new chum
newspaper printing press
niche dating
overboldly
paper mulberry fibre
pedagogical mastery
phantogeusia
phyllis
Phytocoptella
prankees
preliminary treatment
preohmic etch
press zone
procuran
ragged left
raiche
ramse
Sacalunga
safe driving glasses
Samburu National Reserve
sarcomatous angioma
secularity
segment dictionary
sequence control counter
Shaw, Bernard
soapy feel
spacefleets
star wheel motion
stockham
streak reagents
subrationally
subsystem design
sulfydryl
swimming-pool reactor
synthetic resin-bonded paper
target data transmitter
tathion eye drop
teat cupliner
television corporation
Thiofeniclin
thiopeptin
troub
tuskless
two-sided mosaic pickup tube
under-barber
unirradiated fuel
viluite (wiluite)
Viola orientalis
weezies
western tanagers
windowing facility
yellow-headed blackbird
yuriy