2022年人教版生物必修二知识点总结.docx

精品_精品资料_人教版生物必修二学问点总结 （Humanteachingeditionbiological compulsory two knowledge points summary）Zhengzhou class 1106 singingI. The Basic Law of heredity1 the law of segregation of genes The advantages of pea as a material:(1) pea can be strictly self pollinated, and it is closedpollinated and can maintain pure breed under natural conditions.(2) varieties have distinguishable characters.The artificial hybridization test process: left pistils, emasculation bagging anti interference, artificial pollinationThe geneticphenomenonof a pairof relativecharacters:a pair of homozygous parents with a pair of relative characterscrossed, and the offspring showed a kind of expressionThe charactersof F1 and F2 generationswere separated,and the separation ratio was 3:1.The essence of the law of gene segregation: in heterozygouscells,alleleslocatedon a pairof homologous chromosomeshave可编辑资料 - - - 欢迎下载精品_精品资料_Certainindependence,when the organism isin meiosis,alleles are separated by homologous chromosomes, respectivelyIn two gametes, independently transmitted to the offspring as gametes.2 the law of free combination of genesThe genetic phenomenon of two pairs of relative characterscontrolledby two alleles:hybridizationof homozygousparents with two pairs of relative charactersAfter generation of F1 selfing, offspring appeared in fourphenotypes,with a ratioof 9:3:3:1.Each of the four phenotypes is pureZygote accounted for 1/16 in the two generations, accountingfor 4/16; the proportion of dominant individuals accounted for 9/16; the proportion of double recessive individuals accounted for 1/16;The singleheterozygoteaccounted for2/16 * 4=8/16; the double heterozygote accounted for 4/16; the parent type proportionaccounted for 9/16 and 1/16; the proportion of recombinanttypesEach accounted for 3/16, 3/16The essence of the law of free combination of genes: the separation or combination of non allelic genes located on non homologous chromosomes is not mutually exclusive可编辑资料 - - - 欢迎下载精品_精品资料_Interfering. In meiosis, gametes are formed on the homologous chromosomes and separated from each other at the same timeA free combination of non allelic alleles on the source chromosome.Using the principle of free combination of genes to cultivate new varieties: good characters are in different varieties,The best varieties were obtained by crossbreeding first,selectingthe ones thatmet the requirements,and then carrying out continuous self - pollination.Memory point:1. gene segregation law: a pair of relative characters of two biological pure hybrids, the offspring only show dominant characters;Traitsegregationappeared in the two offspring,and the ratio of dominant characters to recessive characters was close to3:1.The essence of the 2. gene segregation law is that in a heterozygous cell, a pair of homologous chromosomes is found to be independent,In meiosis, gametes are separated and separated into two gametes,可编辑资料 - - - 欢迎下载精品_精品资料_Independently transmitted to offspring by gametes.3. genotype is the memory factor of trait expression, while phenotype is the form of genotype. Phenotype = genotype + EnvironmentCondition.The substance of the 4. gene combination law is that the separation or combination of non allelic genes located on non homologous chromosomes is not mutually exclusiveDisturbed. In meiosis, gametes are formed on the homologous chromosomes and separated from each other at the same timeA combinationof non allelicalleleson chromosomes. Withinthe range of the laws of the freecombinationof genes, individuals with the N alleleThe gametes produced may have at most 2n species.Two, cell proliferation(1) cell cycle: a continuous division of cells, starting from the completion of a division, until the next division is complete.(2) mitosis:The biggest feature of interphase is the replication of DNA molecules and the synthesis of proteins可编辑资料 - - - 欢迎下载精品_精品资料_The main changes of chromosomes in prophase are prophase, metaphase, division and anaphase. EspeciallyNote the doubling of chromosome numbers at anaphase due to mitotic division.The difference of mitosis between animals and plants: theformationof spindlein A. is different;the modeof cytokinesis is different at the end of b.(3) meiosis:Object: sexually transmitted organismsPeriod: primordial germ cells form mature germ cellsFeatures: chromosomes are duplicated only once, and cells divide two times continuouslyResults: the number of chromosomes in the newly created germcellswas reduced by halfthan thatof the originalgerm cells.Major changes in chromosomes during sperm and egg formation: meiosis, first interphase, chromosome replication, prophaseHomologous chromosomesform fourbodies often crosscrossing between non sisterchromosomes, and metaphase chromosomesare homologousOn the equatorial plate, the latter chromosomes are separated可编辑资料 - - - 欢迎下载精品_精品资料_at the sametime,while the non homologous chromosomesare free; the second prophase of meiosis is stainedThe body is randomly distributed in the cell, the centromereof the metaphase chromosomeisarranged on the equatorialplate, and the centromereof the laterchromosomeisdividedand dyedSeparation of monomeric bodies.Identificationof the patternsof mitosisand meiosis:inthe case of diploid organismsThere are no homologous chromosomes in 1. cells.Meiosissecond division2. having homologous chromosomes, forming four bodies, arranged on an equatorial plate, or separating from each other. Meiotic first division3. homologous chromosomes do not have these particular behaviors.MitosisMemory point:The result of 1. meiotic division is that the number of chromosomes in the newly created germ cells is less than half that of the original reproductive cell.During meiosis 2., homologous chromosomes in the associationare separatedfrom each other,indicatingthatchromosomesare independent of each other; two homologous可编辑资料 - - - 欢迎下载精品_精品资料_When the chromosome moves toward which pole is random, different pairs of chromosomes non homologous chromosomes can be freely combined.3. the halving of the number of chromosomes in meiosis occurs in the first division of meiosis.4. A spermatogoniaundergoes meiosisto form foursperm cells, and sperm cells undergo complex changes to form sperm.5. an egg cell undergoes meiosis, forming only one egg cell.6. for sexually transmitted organisms, meiosis and fertilization are necessary for the maintenance of each organism's precursor cellsThe constancy of the number of chromosomes is important for biological inheritance and variationThree 、 sex determination and sex linked inheritance(1) XY type of sex determination: the female has a pair of identical sex chromosomes XX, and the male has a pairA heteromorphic sex chromosome XY. Meiosis produces spermatozoa thatproduce sperm containingthe X chromosomeand contain Y stainingSomatic sperm. The female produced only one egg cellcontaining the X chromosome. Fertilization occurs when X spermatozoa and可编辑资料 - - - 欢迎下载精品_精品资料_Y spermatozoa are associated withThe chances of egg cell binding are equal, so the chances of male and female births are equal, with a ratio of 1:1.(2) recessive inheritance of X such as color blindness, hemophilia, Drosophila wink, female, leaf shape, etc.Male patients are more than female patientsIt belongs to the cross i.e. Grandpa genetic atavism, daughter and grandsonFemale patients whose fathers and sons are patients; malessufferfrom illness,and theirmothers and females are at least carriers(3) recessiveinheritanceon the X chromosomee.g.,resistance to VD rickets, pendulum nystagmusFemale patients are more than male patients. Continuous generation.A male patient whose mother and daughter must be a patient.(4) genetic inheritance on the Y chromosome e.g., external auditory canal hirsutismFather to son, pathogenicgenes to childrenand grandchildren, with successive generations, also known as holandric.可编辑资料 - - - 欢迎下载精品_精品资料_(5) the relationshipbetween sexualinheritanceand the law of segregation of genes: genes associated with sex, sexchromosomes, and sex chromosomesA pair of homologous chromosomes, the sex linked inheritance, in essence, conforms to the law of gene segregation.Memory point:1. chromosomesinlivingcellscan be dividedintotwo groups: chromosomes and sex chromosomes.There are two main ways of determiningsex: one is XY, the other is ZW.2. characteristics of sexual inheritance:(1) the characteristics of X with autosomal recessive male patients than female patients; with atavism due toThe disease gene is on the X chromosome, which is usually passed through the daughter to the grandchild; the father and the son of the female patient must be sufferingConversely, the male patient must have been transmitted to the causative gene by his mother.(2) X chromosome dominant inheritance features: female patients are more than male patients, most of whom havecontinuousgeneration,thatis, fromgenerationto generation可编辑资料 - - - 欢迎下载精品_精品资料_There are patients, male patients, mothers and daughters must be patients.(3) genetic characteristics associated with Ychromosome: all patients are male; the causative gene, father, son, andoffspring Xian Xiong genetic.Four. The nature of genes(1) DNA is the major genetic materialBiologicalgeneticmaterial:in the whole biologicalworld,the vast majority of organisms are using DNA as genetic material.DNABiologicalcellularstructuresof biologicaland DNAviruses,DNA is genetic material; only a small number of viruses such as AIDSThere is no DNA, only RNA, and RNA is genetic material, such as viruses, SARS viruses, avian influenza viruses, etc.Prove the experimental design idea that DNA is a genetic substance: try to separate DNA from protein, individually and directlyTo observe the role of DNA.(2) the structure and replication of DNA molecules可编辑资料 - - - 欢迎下载精品_精品资料_Structure of DNA moleculeThe basic unit of A.: deoxy nucleotides consisting of phosphoric acid, deoxy ribose, and bases.B. long chain of nucleotides: polymerized by a certain order of deoxy nucleotidesC. plane structure:D. spatial structure: regular double helix structure.E. structure features: diversity, specificity and stability.Replication of DNAA. time: mitotic interval or the first division of meiosisB. Features: edge resolution, edge replication, half preserving replication.C. conditions: templates two strands of DNA molecules, raw materials four free deoxy nucleotides, enzymes helicase,DNA polymerase, DNA ligase, etc., energy ATPD. result: the DNA molecule, like template DNA, was generated by replication.E. meaning: the inheritance of genetic information to the offspring by replication keeps the continuity of genetic可编辑资料 - - - 欢迎下载精品_精品资料_information.(3) the structure and expression of genesThe concept of genes: genes are DNA molecular fragments with genetic effects, and genes are arranged linearly in chromosomes.The process of protein synthesis by gene control:Transcription: the formation of messenger RNA by the pairing of bases with the template of one strand of DNA.In the ribosome, Messenger RNA is used as a template to transport RNA as a vehicle for the synthesis of certain amino acidsOrdered protein molecules Memory point:1. DNA is a substance that produces stable genetic changes intype R bacteria, and the various traits of bacteriophages are transmitted through DNAThe two experiments showed that DNA is a genetic material.2. the genetic material of all living things is nucleic acid.The cell contains both DNA and RNA and contains only DNA biological inheritance可编辑资料 - - - 欢迎下载精品_精品资料_The qualityisDNA, and the geneticmaterialof a smallnumber of virusesis RNA.Since the vast majorityof biologicalgenetic material is DNA, soDNA is the major genetic material.The variation of the order of 3. base pairs constitutes the diversity of DNA molecules, and the particular alignment of base pairs,The specificity of each DNA molecule is also formed. This explains the diversity and specificity of organisms from the molecular levelBecause.4. the transmission of genetic information is accomplished bythe replicationof DNAmolecules.Geneexpressionis controlled by DNA proteinsAchieved by synthesis.The unique double helix structure of 5.DNA provides a precise template for replication, and ensures replication by complementation of base pairsCapable of proceedingaccurately.The reciprocalratiobetween the two complementary chains is reciprocal. In the entire DNA molecule, the purineSum of bases = sum of pyrimidine bases. In the entire DNA可编辑资料 - - - 欢迎下载精品_精品资料_molecule, the ratio is the same as for each chain in the molecule.The 6. offspring are similar in character to their parents, because the offspring acquire a copy of parental reproduction of DNA.SevenGenes are DNA fragments with genetic effects, geneticallyarranged on chromosomes, and chromosomesare vectorsof genes.8. because different genes have different sequence of nucleotide base order, so different genes are differentGenetic information.i.e.,the DNAof the gene, the nucleotide order, represents the genetic information.The arrangement of the deoxyribonucleic acid of the 9.DNA molecule determines the sequence of nucleotides in the messenger RNA, Messenger RNAThe arrangement of nucleotides determines the order of amino acids, and the arrangement of amino acids determines the proteinThe specificity of the structure and function, thus enabling organisms to exhibit a variety of genetic characteristics.Genes control the synthesis of proteins: BasesBase number due to: base number on mRNA: amino acid number可编辑资料 - - - 欢迎下载精品_精品资料_=6:3:1.The amino acid codon is themessenger RNA on the threeAdjacent bases are not bases on the transport RNA.Transcriptionand translationstrictlyfollowthe principleof base complement matching. Be careful：When paired, the A corresponds to U on the RNA.10. all genetic traits are controlled by genes. Some genes control the metabolic process by controlling the synthesis of enzymes;Another way in which genes co