[紧急]四十分钟在线等 英语生物题目humans are thought to have evolved during the _eraa.cenozoic b.Mesozoicc.Paleozoicd.Precambriawhich group of organisms is believed to have been the earliest to evolvea.mammalsb.Cyanobacteriac.land plant

[紧急]四十分钟在线等 英语生物题目humans are thought to have evolved during the _eraa.cenozoic b.Mesozoicc.Paleozoicd.Precambriawhich group of organisms is believed to have been the earliest to evolvea.mammalsb.Cyanobacteriac.land plant
[紧急]四十分钟在线等 英语生物题目
humans are thought to have evolved during the _era
a.cenozoic
b.Mesozoic
c.Paleozoic
d.Precambria
which group of organisms is believed to have been the earliest to evolve
a.mammals
b.Cyanobacteria
c.land plants
d.aquatic dinosaurs
which of the following fossils are not found in sedimentary
a.amber
b.imprints
c.petrified wood
d.frozen mammoths
which of these is a period in the Mesozoic era?
a Ordovician
b devonian
c Jurassic
d tertiary
which period of geologic time was marked by an enormous increase in the diversity of life forms
a the Permian period
b the Cambrian
c the quaternary
d the Jurassic
what type of rock are most fossils found in
a sedimentary
b igneous
c metamorphic
d volcanic
the earliest organisms were most likely_
a eukaryotic
b prokaryotic
c protobionts
d multicellular
which of the following was probably not present in large amounts in the atmosphere at the time life is thought to have originated
a water
b carbon monoside
c oxygen gas
d carbon dioxide
what is the movement of genes into and out of a gene pool called?
a Radom mating
b gene flow
c nonrandom mating
d direct evolution
natural processes such as speciation and gradualism provide the genetic basis for_
a sexual reproduction
b spontaneous generation
c biogenesis
d evolution
which of the following is not a factor that causes changes in the allelic frequencies of individuals in a population
a stabilizing
b disruptive selection
c random selection
d directional selection
which of the following lines of evidence for evolution is indirect
a fossils
b pesticide resistance
c all of these
d observed allele frequency changes
_is a machanism for change in a population of organisms
a artificial selection
b natural selection
c analogous structures
d homologous structures
which dating method relies on the position of rock layers
a radiometric
b relative
c absolute
d morphology
本人在此跪求各位知识帝尽量快一些

[紧急]四十分钟在线等 英语生物题目humans are thought to have evolved during the _eraa.cenozoic b.Mesozoicc.Paleozoicd.Precambriawhich group of organisms is believed to have been the earliest to evolvea.mammalsb.Cyanobacteriac.land plant
1、A 新生代后期有人类出现
2、b 蓝细菌最先进化
3、c 木化石
4、c 中生代包括Triassic Period,Jurassic Period侏罗纪,Cretaceous Period
5、d 侏罗纪时期的特点是生命形式的多样性大幅增加
6、d 这个我也不太确定,个人认为是火山岩吧
7、c 有机分子的聚集,由膜包围.再到原核生物再到真核生物
8、b 碳单甙
9、c 选择性交配,基因库的流入和流出
10、a 有性生殖
11.、c 随机选择
12、c 三个都是间接进化的证据
13、b 自然选择是种群进化的机理
14、a 辐射测量（这题我也不确定,辐射会有衰减,所以我认为是这个）
希望能给你一点帮助