1, basic law succession
Isolation of (1) gene
① Advantages of pea material: (1) Pea is strictly self-pollinated and closed-pollinated, and can remain pure under natural conditions. (2) Varieties with easily distinguishable characters.
② Experimental flow of artificial hybridization: castration (left pistil) → bagging (tamper-proof) → artificial pollination.
③ Trait opposition: the performance of a pair of homozygous hybrid parents whose relative characters are F 1 and 3: 1 separated from F2 generation.
(4) The essence of gene segregation: the heterozygote cells are located between alleles on a pair of homologous chromosomes and have certain independence. In the process of biological meiosis, alleles will be different. Homologous chromosomes are independent, they split into two independent gametes and passed on to future generations.
(2) the law of gene free combination
① Two pairs of alleles are controlled by two pairs of opposite traits: two pairs of parents with homozygous opposite traits cross, F 1 selfing, and the ratio of four types of offspring is 9: 3: 3: 1. Phenotypic homozygotes accounted for116 and 4/16 respectively in the second generation; The proportion of double dominant individuals is 9/ 16, and the proportion of double recessive individuals is116; Single heterozygote 2/16× 4 = 8/16,4/16; The double heterozygosity of each parent type is 9/ 16,116; Recombinant, 3/ 16, 3/ 16 />(2) The essence of the law of gene free combination: allele separation or non-homologous chromosome combination does not interfere with each other. During meiosis of gametes, alleles on homologous chromosomes are separated from each other and non-alleles are separated, and non-homologous chromosomes are freely combined.
(3) Using the principle of gene free combination law, we can cultivate new varieties: the excellent characteristics of different varieties, and the first hybrid car can get homozygous variety selection to meet the needs of constant self.
Memory point:
1。 The phenomenon of gene separation: a pair of pure traits of two organisms oppose this mixing, and the second generation only shows the separation of dominant traits. The quantitative ratio of dominant traits to recessive traits is close to 3: 1.
2。 The separation phenomenon of a pair of homologous chromosome genes: heterozygous cell material, which has certain independence. In the process of meiosis, gametes and alleles are separated independently, split into two independent gametes and passed on to future generations.
3。 Genotypic characteristics memory phenotype genotype performance. Phenotype = genotype+environmental conditions.
4。 The essence of the law of free combination of genes is that alleles of non-homologous chromosomes are separated or their combinations do not interfere with each other. In the process of meiosis of gametes, alleles on homologous chromosomes are separated from each other and become non-alleles. Non-homologous chromosomes are freely combined within the scope of free rules, and there may be as many as 2N gene combinations in which n alleles produce gametes. /& gt； cell multiplication
(1) Cell cycle: refers to the continuous division of cells, from the completion of one division to the next division until the completion of the first division.
(2) Mitosis:
The biggest feature of interphase is the replication of DNA molecules and the synthesis of protein.
The main changes of mitotic chromosomes: clear metaphase arrangement appeared in the early stage; Late segmentation; Eventually disappear. Special attention should be paid to the late centromere division, and the number of temporary chromosomes should be doubled.
The mitotic modes of animal cells and plant cells are different: the spindle is formed in advance; Eventually the cytoplasm divides in different ways.
(3) Meiosis:
Object: the biological period of sexual reproduction: the characteristics of mature germ cells formed by primitive germ cells: chromosomes are copied only once, and cells continue to divide. There are two results: the number of chromosomes in the new germ cells is half that of the original germ cells.
The main changes of chromosome formation in sperm and egg cells are as follows: chromosome replication in the first stage of meiosis, homologous chromosomes combine to form tetrads (cross-exchange often occurs between non-sister chromatids), the middle homologous chromosomes are arranged on the equatorial plate, and the non-homologous chromosomes separated in the later stage are freely combined; The distribution of scattered chromosomes in cells at the second prophase of meiosis, centromere division of chromosomes arranged on the equatorial plate and separation of chromosome monomers.
Mitotic and meiotic pattern recognition: (for example, bond diploid organisms)
1. 1 cells have no homologous chromosomes ... or have declined in morality and art.
Homologous chromosomes of 1.2 cells
2. 1 homologous chromosomes combine to form tetrads, which are arranged on the equatorial plate or separated from each other ... the first meiosis.
In 2.2, the special behavior that homologous chromosomes do not have-mitosis.
Memory point:
Due to meiosis, the chromosome number of the new generation germ cells is reduced by half compared with that of the original germ cells.
Homologous chromosomes are separated from each other during meiosis, which shows that they have certain independence. Homologous chromosomes and chromosomes are random, and different chromosomes (non-homologous chromosomes) can be combined freely.
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During meiosis, the number of chromosomes halved. Spermatogonial cells form four sperm cells after meiosis, and then form sperm through complex changes.
Five. Oocyte meiosis, forming egg cells.
. 6。 For sexually reproducing organisms, it is very important to keep the chromosome number of somatic cells of each offspring constant during meiosis and fertilization.
3. Sex determination and sex-linked inheritance
(1)XY sex determination: there are a pair of homozygous chromosomes (XX) in women and a pair of heterozygous chromosomes (XY) in men. Meiotic sperm includes sperm with X chromosome and sperm with Y chromosome. Only women's eggs contain X chromosomes. At the time of fertilization, X sperm and Y sperm have equal opportunities to combine with eggs, and the offspring born to men and women have equal opportunities, with the ratio of 1: 1.
(2)X-linked recessive genetic characteristics (such as color blindness, hemophilia, Drosophila eye and building inheritance)
① Male patients are more than female patients.
2。 It belongs to the atavism of cross inheritance, grandpa's daughter →→→→→ grandson.
(3) Female patients, both father and son are sick, and their mothers and women are at least operated on.
(3) recessive inheritance of X chromosome (such as VD rickets and nystagmus)
(1) There are more female patients than male patients.
(2) the second generation continuous phenomenon.
③ Male patients must be the mother and daughter of the patient.
(4) Genes on Y chromosome (such as hirsutism of external auditory canal)
The father's son, the son is passed on to the grandson, and the continuation of generations is also called the pathogenic gene that is only inherited by men.
(5) In the relationship between sex-linked inheritance and gene: the sex chromosome is a pair of homologous chromosomes, which has the nature of sex-linked inheritance corresponding to gene separation.
Memory point:
1。 Chromatin in biological cells can be divided into two categories: autosomes and sex chromosomes. There are two main ways to determine biological sex: one is XY type and the other is ZW type.
2。 Characteristics of sex-linked inheritance:
Characteristics of (1) and X-linked recessive inheritance: there are more male patients than female patients; Atavism (because the pathogenic gene is on the X chromosome, the grandson of the father and son of the male patient passes through the daughter of the female), and some patients, on the contrary, the male patient must be the pathogenic gene of his mother.
(2) Characteristics of X-autosomal dominant inheritance: There are more female patients than male patients, and most of them are patients' mothers and daughters who have continued for several generations. Male patients must have patients.
(3) Genetic characteristics of Y chromosome: All patients are male, and the disease genes are passed down from generation to generation (only male). /& gt； Nature of
The DNA of (1) gene is the main genetic material.
① Biological genetic material: DNA is the biological basis of genetic material in organisms. DNA organisms (biological cell structure and DNA virus), DNA is genetic material, only a few (such as AIDS virus, SARS virus, avian influenza virus, etc. There is no DNA, only the genetic material of RNA and RNA virus. /& gt； (2) Experimental design idea to prove that DNA is genetic material: Try to separate DNA from protein and observe the function of DNA directly. /& gt； Structure and replication of DNA molecules
①DNA molecular structure
The basic unit of deoxynucleotide (phosphoric acid, deoxyribose and alkali).
B long chain of deoxynucleotides: deoxynucleotides are polymerized in a certain order.
Plane structure:
D is the double helix structure rule of spatial structure.
Structural features: diversity, specificity and stability.
(2)DNA replication
Time: The first stage of mitosis or meiosis.
B. Features: semiconservative replication copied when unwinding.
Conditions: two-strand template (DNA molecule), material (four deoxynucleotides), enzyme (helicase, DNA polymerase, DNA ligase), and energy (ATP).
D is the result: DNA is generated as a template by copying the same DNA molecules.
Significance: By copying genetic information and transmitting it to future generations, the continuity of genetic information is maintained. /& gt； (3) the structure and expression of the gene
② Genes control the synthesis process of protein;
Transcription: DNA template chain messenger RNA is formed according to the principle of base complementary pairing.
Translation: Messenger RNA is used as a template in the synthesis of ribosomes and transfer RNA, as well as an amino acid sequence carrier, protein molecule.
Memory point:
1。 DNA is the material of stable genetic variation of various characters of R-phage. These two experiments show that this kind of DNA is the genetic material passed on to future generations through DNA.
2。 All genetic material is nucleic acid. There are both RNA and DNA in cells, and the genetic material containing organisms is DNA, which is one of the few genetic materials of an RNA virus. Because the vast majority of genetic material is DNA, this DNA is the main genetic material.
3。 On the basis of changing order, the diversity of DNA molecules and the specific order of base pairs constitute the specificity of each DNA molecule. The diversity and specificity of this microorganism, from the molecular level.
4。 The transmission of genetic information is through the replication of DNA molecules. Gene expression is the DNA that controls protein's synthesis.
Five. The only way to provide accurate templates is to ensure that the double helix structure of DNA molecules can be replicated with high accuracy through complementary base-pairing copies. The ratio of the relationship between two complementary chains. In the whole DNA molecule, purine bases and pyrimidine bases. In the whole DNA molecule, the proportion of each strand of the molecule is the same.
. 6。 Because the DNA characteristics of offspring and parents are similar.
7。 The DNA fragment of gene is a kind of genetic effect, the gene on linear chromosome and the carrier of gene on chromosome.
8。 Input deoxynucleotide sequences (base sequences) of different genes, so different genes contain different genetic information. (that is, the deoxynucleotide sequence of a gene represents genetic information).
9。 The deoxynucleotide sequence of DNA molecules determines the ribonucleotide sequence of messenger RNA, the ribonucleotide sequence of amino acid sequence of messenger RNA, and the protein specificity of the structure and function of amino acid sequence, thus making organisms show various genetic characteristics. Genes control the number of bases in protein's synthetic genes: number of bases on mRNA: number of amino acids = 6: 03: 0 1 sec. Three adjacent nucleotides of amino acid codon do not forward nucleotide RNA messenger RNA. In the process of transcription and translation, the principle of base complementary pairing is strictly followed. Note: When pairing, the arrangement of RNA is U-shaped.
10。 The genetic characteristics of all living things are influenced by genes. Some genes are controlled by controlling the metabolic process of enzymes; In another case of gene trait control, traits are directly affected by controlling the molecular structure of protein. 5. Biological variation
The mutation of (1) gene is
① The concept of gene mutation: the change of the genetic structure of DNA molecules with base pairs leads to the addition, deletion or change.
② Characteristics of gene mutation: 1. Gene mutation is common in organism B, and it happens randomly. The lower the mutation frequency of C gene, the greater the harm of most gene mutations. Non-directional mutation
(3) Meaning gene mutation: the fundamental source of biological variation, and biological evolution provides the initial raw materials.
④ Gene mutation type: natural mutation induced mutation.
⑤ Artificial mutation breeding: Artificial mutation can increase frequency variation and greatly improve biological characteristics.
(2)
(1) Chromosome structure changes: deletion, addition, inversion, translocation chromosome aberration. : Meow syndrome. /& gt； (2) With the increase or decrease of chromosome number, the changes of chromosome and genome form in cells increase exponentially. /& gt； (3) Characteristics of genomes: Genomes A and A do not contain homologous chromosome B, while genome A contains complete genes in C that control biological traits, with the same shape, size and function.
(4) Diploid or polyploid: A single cell contains several times as many fertilized eggs as some genomes; Develop into unfertilized germ cells (sperm or eggs), such as haploids (possibly one or more genomes).
⑤ Method of artificially inducing polyploid: colchicine seeds germinate into seedlings. Principle: When colchicine is used in cell division, it can inhibit the formation of spindle and chromosome separation in prophase, and double the number of chromosomes in cells.
Characteristics of polyploid plants: The contents of carbohydrates, protein and other nutrients in thick stems, leaves, fruits and seeds are more than increasing. trait
⑦ Haploid plants: The plants grow weakly and are highly sterile. Obtaining haploid plants: retired anther culture. Haploid breeding significance: greatly shorten the breeding cycle (only two years).
Memory point:
1。 Genome is a group of cells with the same morphology and function on non-homologous chromosomes, but the vector controls the growth and genetic variation of developing organisms. A set of chromosomes is called genome.
2。 Changed the genetic variation of genetic material, including gene mutation, gene recombination and chromosomal mutation. The biggest feature of gene mutation is to generate new genes. It is a genetic change of chromosome locus. This gene mutation not only exists widely, but also occurs randomly, and the mutation rate is low. Most pests have no directional mutation. Gene mutation is the fundamental source of biological variation and provides the initial raw materials for biological evolution. The original gene recombination did not produce new genes, but the mixed genes were recombined into individuals who were not in the same person. In the process of gene recombination through sexual reproduction, it provides an extremely rich source of biological variation. This is an important reason, which is of great significance to the formation of biodiversity and biological evolution. The above two variations are invisible. With the help of a microscope, chromosome variation changes the structure and quantity of chromosomes, which can be seen clearly under the microscope. What is the most important difference from the first two? Changes related to chromosome changes. This structural change, the change of the number of individuals and the times, and the change of the times are of great significance in real life, which supports a series of concepts and types, such as diploid, polyploid and haploid sports species of the genome.
Human genetic diseases and eugenics
(1) eugenic measures: forbidding consanguineous marriage, genetic counseling, promoting childbearing age and prenatal diagnosis.
(2) Prohibition of consanguineous marriage: Couples who marry their ancestors' close relatives greatly increase the chances that their children will inherit the same disease gene and suffer from recessive genetic diseases. Memory point:
Multi-fingered, achondroplasia is a single-gene autosomal dominant genetic disease, vitamin D-resistant rickets is a single-gene X-chromosome dominant genetic disease, albinism, phenylketonuria, congenital deaf-mute autosomal recessive genetic disease, progressive muscular dystrophy, color blindness, hemophilia X-linked recessive single-gene genetic disease, cleft lip and anencephaly, and juvenile diabetes are genetic diseases; Chromosome diseases such as autosomal dominant inheritance disease 2 1 trisomy syndrome, meow syndrome and gonadal hypoplasia.
cytoplasmic inheritance
(1) Characteristics of cytoplasmic inheritance: matrilineal inheritance (reason: almost all cytoplasm of fertilized eggs comes from mother cells), and there is no certain separation ratio (reason: offspring of germ cell genetic material are randomly and unequally distributed to daughter cells during meiosis).
(2) Material basis of cytoplasmic inheritance: DNA molecules mainly distributed in mitochondria and chloroplasts exist in cytoplasm, which can control some characters. Memory point:
The egg 1 contains a lot of cytoplasm, and the sperm only contains a very small amount of cytoplasm, almost all of which comes from the fertilized egg in the egg, so that the cell quality of the genetic material representing the controlling character in the cytoplasm is passed on to the eggs of the offspring, so the total offspring has the characteristics of the female parent.
2。 Its main feature is that the offspring of cytoplasmic maternal line will not have a certain separation ratio. Cytoplasmic genetic characteristics: Almost all fertilized eggs' cytoplasm comes from egg formation, meiosis, genetic material in cytoplasm and random uneven distribution of eggs. The material basis of cytoplasmic inheritance: chloroplast, mitochondria and cytoplasmic DNA.
3。 Both nuclear inheritance and cytoplasmic inheritance have their own relative independence. This is the chromosome structure in cytoplasm, because, although not found, quality genes and nuclear genes can self-replicate, transcribe and translate to control the synthesis of protein, that is, they have stability, continuity, variability and independence. Nuclear inheritance, cytoplasmic inheritance and interaction, in many cases, due to cytoplasm. /& gt； Introduction/>; Genetic engineering (1) Genetic engineering
Standard concept: In vitro, through artificial "cutting" and "splicing" of DNA molecules, biological gene modification and conceptual combination, and then introducing them into recipient cells for asexual reproduction, therefore, human beings need to be produced by recombinant cells expressing gene products in recipient cells.
Popular concept: according to people's will, an individual organism is copied, then transformed, and then to the cells of another organism to directionally transform the genetic traits of that organism. /& gt； (2) gene manipulation tools/> a. gene scissors-restriction endonuclease (restriction endonuclease for short).
(1) distribution: mainly concentrated in microorganisms. /& gt； (2) It is characterized by specificity, that is, it cuts a specific cleavage point by identifying a specific nucleotide sequence.
(3) Results: Sticky ends (base pairs) were produced.
B. gene needle -DNA ligase.
① Connecting part: Is the phosphodiester bond hydrogen?
Results: Two identical sticky ends were connected.
C. basic difficult means of transport-transport carrier
① Function: Exogenous genes are introduced into recipient cells. /& gt； ② Conditions: 1. It can be replicated and stably maintained in host cells. , with multiple restriction points.
Some marker genes.
③ Category: plasmid, phage and animal and plant viruses.
④ Plasmid, characterized by vector plasmid being the most commonly used genetic engineering.
(3)
A. extracting a target gene
The concept of target gene: people need specific genes, such as human insulin gene, insect-resistant gene, disease-resistant gene and interferon gene. /& gt； Extraction path:/> B, combining the target gene with the vector
The plasmid DNA (vector) of the target gene is cut with the same restriction enzyme to produce the same sticky end, the cut target gene is mixed with the cut plasmid, and an appropriate amount of DNA ligase is added to form a recombinant DNA molecule (recombinant plasmid).
C.
The target gene was introduced into recipient cells: Escherichia coli, Bacillus subtilis, Agrobacterium tumefaciens, yeast, plant and animal cells.
D, detecting the expression of the target gene.
The detection method is as follows: E.coli cells containing plasmid of antibiotic resistance gene become corresponding antibiotics, if the cells containing recombinant plasmid grow normally.
Expression: The recipient cells showed specific characteristics, indicating that the expression of the target gene was completed. For example, cotton genes are introduced into cotton cells and killed by eating cotton bollworm leaves; The insulin gene is introduced into E.coli, which can synthesize insulin.
(4) Achievements and development prospects of genetic engineering.
A. Genetic engineering and health care B. Genetic engineering, agriculture, animal husbandry and food industry
C. genetic engineering and environmental protection
Memory point:
1 is a necessary feature of the vector: it has several restriction sites and some markers stably when replicating and storing in host cells, so as to facilitate the connection of foreign genes; Genes to facilitate screening. Vector plasmid is the most commonly used genetic engineering, which exists in many organisms, such as bacteria and yeast, and is a small circular DNA molecule that can replicate independently.
2。 The general steps of genetic engineering include: ① extracting the target gene combined with the vector; ② ③ ④ Introduce the target gene into the recipient cell and detect the expression of the target gene.
When recombinant DNA molecules enter the recipient cells, the recipient cells must have specific characteristics, which is completed during the expression of the target gene. /& gt； The difference is the same as that of the vector * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * /& gt； Gene diagnosis uses the principle that DNA hybridizes with radioisotopes and fluorescent molecules, such as DNA molecules, to detect diseases by labeling and identifying genetic information in the detected samples.
6。 Gene therapy is a healthy cell with gene defects in foreign genes, which can achieve the purpose of treating diseases. Evolution of organic world
(1) Natural selection theory: overgrowth, survival competition, gene mutation, survival of the fittest.
(2) Species: A group of individuals who are distributed in a certain natural area, have certain morphological structure and physiological functions, mate and reproduce with each other in a natural state, and can produce fertile offspring.
Group: A group of individuals of the same species live in the same place.
Gene bank: contains genes in all individual populations.
(3) The basic viewpoint of modern biological evolution theory: population is the basic unit of biological evolution, and the essence of biological evolution is the change of gene frequency of population. Mutation and gene recombination, natural selection and speciation are three basic links. Through their comprehensive influence, population division will eventually lead to the formation and isolation of new species.
(4) Gene mutation and gene recombination, in order to produce raw materials for biological evolution, natural selection and the changing direction of population gene frequency determine the direction of biological evolution. Isolation is a necessary condition for the formation of new species (forming reproductive isolation marks the formation of new species).
The basis of modern biological evolution theory: natural selection theory.
Memory point:
1。 The process of biological evolution is essentially the process of population gene frequency change.
2。 The basic view of modern biological evolution theory with natural selection theory as the core is that population is the basic unit of biological evolution and the essence of biological evolution characterized by the change of population gene frequency. Mutation and gene recombination, natural selection and speciation are three basic links. Through their comprehensive influence, population division will eventually lead to the formation and isolation of new species.
Isolation means that genes between different populations of the same species cannot be freely exchanged under natural conditions. Include geographical segregation and reproductive segregation. Its function is to prevent gene flow among populations, and the gene frequency of populations is a necessary condition and an important part of species formation in different directions.
4。 Interspecies and biological evolution: the development and change of the same species in biological evolution may be longer or shorter. Any change in gene frequency, regardless of size, is considered to be the formation of the evolutionary range of species. It is necessary to break through the boundaries of species to establish the change of gene frequency and form reproductive isolation. /& gt； Every cell of an organism has a complete set of genes, including all the genes necessary for a species to develop into a complete individual.
6。 In vivo, cells do not show totipotency, but differentiate into different tissues and organs, which is the result of selective expression of specific genes in time and space.