沈阳农业大学遗传学期末考试(英文)张守纯

Gene（基因）：A genetic factor (region of DNA) that helps determine a characteristic. Allele(等位基因)：One of two or more alternate forms of a gene.

Locus(座位)：Specific place on a chromosome occupied by an allele.

Genotype(基因型)：Set of alleles that an individual possesses.

Heterozygote(杂合子)：An individual possessing two different alleles at a locus. Homozygote(纯合子)：An individual possessing two of the same alleles at a locus.

分离定律：The principle of segregation states that each individual organism possesses two alleles coding for a characteristic. These alleles segregate when gametes are

formed, and one allele goes into eachgamete.

测交：A testcross reveals the genotype (homozygote or heterozygote) of an individual having a dominant trait and consists of crossing that individual with one having

the homozygous recessive genotype.

自由组合定律：The principle of independent assortment states that genes coding for different characteristics separate independently of one another when gametes are formed,

owing to independent separation of homologous pairs of chromosomes during meiosis.

Genes located close together on the same chromosome do not, however, assort

independently.

基因互作：In gene interaction ,genes at different loci contribute to the determination of

a single phenotypic characteristic.

基因上位：Epistasis is the masking of the expression of one gene by another gene at a different locus. The epistatic gene does the masking；the hypostatic gene is masked. Epistatic

genes can be dominant or recessive.

重组：Recombination is the sorting of alleles into new combinations. Interchromosomal recombination, produced by independent assortment, is the sorting of alleles on

different chromosomes into new combinations.Interchromosomalrecombination,

produced by crossing over,is the sorting of alleles on the same chromosome into

new combinations.

连锁 Linkage between genes causes them to be inherited together and reduces recombination;

crossing over breaks up the associations of such genes.

三点测交：In a three point textcross, an individual heterozygous at three linked loci is crossed with an individual that is homozygous recessive at the three loci.

伴性遗传（Sex-Linked Characteristics）:Characteristics determined by genes on the sex chromosomes are called sex-linked characteristics. Diploid females have two

alleles at each X-linked locus, whereas diploid males possess a single allele at

each X-linked alleles from both parents, but males inherit a single X-linked allele

from their mothers.

从性性状：Sex-influenced characteristics are traits encoded by autosomal genes that are more readily expressed in one sex.

限性性状：Sex-limited characteristics are encoded by autosomal genes whose expression is limited to one sex.

中心法则：The central dogma of molecular biology proposes that information flows in a one-way direction, from DNA to RNA to protein.

外显率：Penetrance is the percentage of individuals having a particular genotype who express the associated phenotype.

表现度：Expressivity is the degree to which a trait is expressed.

拟表型：A phenocopy is a trait produced by environmental effects that mimics the phenotype produced by a genotype.

转化(Transformation)：Transformation is introduction of extraneous DNA in to a sell.

错义突变(Missense mutation):Changes a sense codon into a different sense codon, resulting

in the incorporation of a different amino acid in the protein.

无义突变(Nonsense mutation):Changes a sense codon into a nonsense codon, causing premature termination of translation.

沉默突变(Silent mutation):Changes a sense codon into a synonymous codon, leaving unchanged the amino acid sequence of the protein.

中性突变(Neutral mutation):Changes the amino acid sequence of a protein without altering its ability to function.

群体遗传学：Population genetics is the branch of genetics that studies the genetic makeup of groups of individuals and how a group’s genetic composition changes with time. 母体效应：In genetic maternaleffect,the genotype of the maternal parent determines the phenotype of the offspring.

剂量补偿效应：dosage compensation, equalizes the amount of protein produced by X-liked genes in the two sexes.

减数分裂的意义：1.减数分裂和受精作用的交替进行，保证某一物种染色体数目的恒定。

2.减数分裂基因重组，使后代个体遗传多样化

3.无减数分裂就没有遗传学三大规律

减数分裂和有丝分裂区别：1.有丝分裂是体细胞增殖的分裂方式，减数分裂是性细胞成熟的分裂方

式

2.有丝分裂产生两个遗传物质相同的子细胞，减数分裂产生四个染色体减

半，且遗传组成不同的子细胞。

3.有丝分裂无基因重组，减数分裂间期有基因重组及交叉互换。

孟德尔实验方法特点：1.使用纯种2.有明显区别的单位性状3.进行各世代的谱系记载4.利用统计分析。

染色体的形态：中心着丝点染色体，亚中着丝点染色体，近端着丝点染色体，端部着丝点染色体。

致死基因（lethal gene）：造成细胞或个体死亡的突变基因。但在一定条件下，带有致死基因的个体可以正常生活。

互补作用：两种或两种以上的基因相互补充出现新性状，叫基因的互补作用。具有互补作用的基因叫互补基因。

上位作用：两对基因同时控制一个单位性状发育，其中一对基因对另一对基因的表现具有遮盖作用，这种基因互作类型称为上位作用。

决定性别的因素：1.环境2.性染色体3.基因平衡理论4.染色体倍性5.基因

伴性遗传的特征：1.性状分离比数在两性间不一致2.正反交结果不一致

遗传物质的特点：1.多样性2.可变异性3.稳定性4.可复制性5.决定性状

变异的类型和区分：1.遗传变异和不遗传变异2.环境的原因（1）环境（2）基因型：基因重组：自由组合交叉突变：基因突变染色体畸变

基因突变的一般特性：1.突变的重演行2.突变的可逆性3.突变的多向性4.突变的平行性

5.突变的有利性和有害性

突变的原因：1.自发的复制错误2.自发的化学变化3.化学诱变4.电离辐射

缺失的类别：中间缺失和顶端缺失。