Summary of two compulsory knowledge points of biology in senior one 1. Basic laws of heredity
Isolation of (1) gene
① Advantages of peas as raw materials:
(1) Pea can be strictly self-pollinated and can remain pure under natural conditions.
(2) There are easily distinguishable characters among varieties.
② Experimental process of artificial hybridization: castration (keeping pistil) → bagging (anti-interference) → artificial pollination.
③ Genetic phenomenon of a pair of relative traits: a pair of homozygous parents crossed, and the offspring showed phenotype, F 1 generation selfed, F2 generation separated, and the segregation ratio was 3: 1.
④ The essence of gene segregation: In heterozygote cells, alleles located on a pair of homologous chromosomes have certain independence. When an organism undergoes meiosis, alleles will separate with the separation of homologous chromosomes, enter two gametes respectively, and be passed on to offspring independently with the gametes.
(2) the law of gene free combination
① Genetic phenomenon of two pairs of relative traits controlled by two pairs of alleles: after parents of two pairs of homozygotes of relative traits crossed, F 1 selfed, and four phenotypes appeared in the offspring, with the ratio of 9: 3: 3: 1. Each of the four phenotypes has a homozygote, which accounts for116 in the second generation. The proportion of double dominant individuals is 9/16; The proportion of double recessive individuals is116; Single heterozygote accounts for 2/16× 4 = 8/16; Double heterozygotes accounted for 4/16; The proportions of parental types were 9/ 16 and116, respectively. The proportion of recombination types is 3/ 16 and 3/ 16 respectively.
② The essence of the law of free combination of genes: the separation or combination of nonallelic genes on non-homologous chromosomes does not interfere with each other. In the process of meiosis to form gametes, alleles on homologous chromosomes are separated from each other, while non-alleles on non-homologous chromosomes are freely combined.
(3) The method of cultivating new varieties by using the principle of free combination of genes: excellent characters are selected from different varieties, and then homozygous excellent varieties are obtained through continuous self-crossing.
Memory point:
1. gene segregation phenomenon: when two organisms with a pair of relative traits are hybridized, the first generation only shows dominant traits; The segregation of traits appeared in the second generation, and the quantitative ratio of dominant traits to recessive traits was close to 3: 1.
2. The essence of gene segregation is that it is located on a pair of homologous chromosomes in heterozygote cells and has certain independence. When an organism undergoes meiosis to form a gamete, the alleles will separate with the separation, enter two gametes respectively, and be passed on to the offspring independently with the gametes.
3. Genotype is the memory factor of trait expression, while phenotype is the expression form of genotype. Phenotype = genotype+environmental conditions.
4. The essence of the law of free combination of genes is that the separation or combination of non-allelic genes on non-homologous chromosomes does not interfere with each other. In the process of meiosis to form gametes, alleles on homologous chromosomes are separated from each other, while non-alleles on non-homologous chromosomes are freely combined. Within the scope of the law of free combination of genes, individuals with n pairs of alleles can produce 2n gametes at most.
Second, cell proliferation.
(1) Cell cycle: refers to the continuous division of cells, from the completion of one division to the completion of the next division.
(2) Mitosis:
The biggest feature of interphase is to complete the replication of DNA molecules and the synthesis of protein.
The main changes of chromosomes during mitosis are: prophase appearance; Clear and arrange in the medium term; Late division; Later disappeared. Pay special attention to the temporary doubling of chromosome number caused by centromere division in the later stage.
The differences of mitosis between animal cells and plant cells are as follows: a. The early spindle formation mode is different; B. Cytokinesis at the end stage is different.
(3) Meiosis:
Object: Sexually reproducing organisms.
Stage: Primitive germ cells form mature germ cells.
Features: Chromosomes are copied only once, and cells divide twice continuously.
Results: The chromosome number of the newly produced germ cells was reduced by half compared with that of the original germ cells.
The main changes of chromosomes in the process of sperm and egg cell formation are as follows: during the first meiotic interval, homologous chromosomes in the early stage form tetrads (cross-exchange often occurs between non-sister chromosomes), homologous chromosomes in the middle stage are arranged on the equatorial plate, homologous chromosomes are separated in the later stage, and non-homologous chromosomes are freely combined; Chromosomes in prophase of meiosis are scattered in cells, centromeres in metaphase are arranged on the equatorial plate, and centromeres in anaphase are separated.
Identification of mitotic and meiotic patterns: (taking diploid organisms as an example)
1. There is no homologous chromosome in the cell ... the second meiosis.
2. Homologous chromosomes unite, form tetrads, arrange on the equatorial plate or separate from each other ... the first meiosis.
3. Homologous chromosomes do not have the above special behavior ... mitosis.
Memory point:
1. As a result of meiosis, the number of chromosomes in new germ cells is reduced by half compared with the original germ cells.
2. Synaptic homologous chromosomes are separated from each other during meiosis, which shows that chromosomes have certain independence; When two homologous chromosomes randomly move to which pole, different pairs of chromosomes (non-homologous chromosomes) can be freely combined.
3. In the process of meiosis, the number of chromosomes is halved in the first meiosis.
4. A spermatogonia undergoes meiosis to form four spermatocytes, which undergo complex changes to form sperm.
5. Oocytes undergo meiosis, and only one egg cell is formed.
6. For sexually reproducing organisms, meiosis and fertilization are very important for maintaining the constant number of chromosomes in somatic cells of each offspring, as well as for the inheritance and variation of organisms.
Third, sex determination and sex-linked inheritance
Sex determination pattern of (1)XY type: female has a pair of homozygous chromosomes, and male has a pair of heterozygous chromosomes (XY). When meiosis forms sperm, sperm containing X chromosome and sperm containing Y chromosome are produced. Women only produce one egg cell with X chromosome. When fertilization occurs, X sperm and Y sperm have equal opportunities to combine with egg cells, so the chances of giving birth to males and females in offspring are equal.
(2) It has the characteristics of X recessive inheritance (such as color blindness, hemophilia, Drosophila expression, leaf shape, etc.)
① Male patients are more than female patients.
② It belongs to cross inheritance (atavism), that is, grandfather → daughter → grandson.
③ Female patients, whose father and son are both patients; If a man is sick, his mother and daughter are at least carriers.
(3) recessive inheritance on X chromosome (such as VD rickets and pendulum nystagmus)
① There are more female patients than male patients.
② There are successive generations.
③ Male patients, whose mothers and daughters must be patients.
(4) Inheritance on Y chromosome (such as hirsutism of external auditory canal)
Pathogenic genes are passed on from generation to generation and from son to grandson, which is also called male limited inheritance.
(5) The relationship between sex-linked inheritance and segregation of genes: Sex-linked genes are on sex chromosomes, and sex chromosomes are also a pair of homologous chromosomes. Sex-linked inheritance is essentially consistent with the phenomenon of gene separation.
Memory point:
Chromosomes in biological cells can be divided into two categories: autosomes and sex chromosomes.
There are two main methods to determine biological sex: one is XY type, and the other is ZW type.
2. The characteristics of sex-linked inheritance:
It has the characteristics of (1) recessive inheritance of X chromosome: there are more male patients than female patients; There is atavism (because the pathogenic gene is on the X chromosome, it is generally passed from male to grandson through daughter); The father and son of a female patient must be a patient, while the male patient must have inherited the disease-causing gene from his mother.
(2) It has the characteristics of dominant inheritance of X chromosome: there are more female patients than male patients, and most of them have intergenerational continuity, that is, there are patients from generation to generation, and the mother and daughter of male patients must be patients.
(3) Genetic characteristics of Y chromosome: All patients are male; Pathogenic genes are passed down from generation to generation, and passed from son to grandson (male only).
Fourth, the nature of genes.
(1)DNA is the main genetic material.
① Biological genetic material: In the whole biological world, most organisms take DNA as their genetic material. For organisms with DNA (organisms with cellular structure and DNA viruses), DNA is genetic material; Only a few viruses (such as AIDS virus, SARS virus, avian influenza virus, etc.). ) there is no DNA, only RNA is genetic material.
② Experimental design idea to prove that DNA is genetic material: Try to separate DNA from protein and observe the function of DNA directly.
(2) the structure and replication of 2)DNA molecules
① ① The structure of ①①DNA molecule
A basic unit: deoxynucleotide (composed of phosphoric acid, deoxyribose and bases).
B deoxynucleotide long chain: formed by polymerization of deoxynucleotides in a certain order.
C. plane structure:
D. Spatial structure: regular double helix structure.
E. structural characteristics: diversity, specificity and stability.
②DNA replication
A. Time: the interval between mitosis or first meiosis.
B. features: unwinding and copying; Semi-conservative replication.
C conditions: template (double strand of DNA molecule), raw material (four kinds of free deoxynucleotides), enzyme (helicase, DNA polymerase, DNA ligase, etc. ), energy (ATP)
D. results: DNA molecules similar to template DNA were produced by replication.
E. Significance: Genetic information is transmitted to future generations through replication, thus maintaining the continuity of genetic information.
(3) the structure and expression of the gene
Concept of gene: A gene is a DNA molecular fragment with genetic effect, and the genes are arranged linearly on the chromosome.
② Gene controls the process of protein synthesis:
Transcription: the process of forming messenger RNA by using a DNA strand as a template and the principle of base complementary pairing.
Translation: protein molecules with certain amino acid sequences were synthesized in ribosomes using messenger RNA as template and transport RNA as carrier.
Memory point:
1.DNA is a substance that causes stable genetic changes of R-type bacteria, and various characteristics of phage are also passed on to future generations through DNA. These two experiments proved that DNA is a kind of genetic material.
2. The genetic material of all living things is nucleic acid. The biological genetic material that contains both DNA and RNA in cells and only DNA is DNA, and the genetic material of a few viruses is RNA. Because the genetic material of most organisms is DNA, DNA is the main genetic material.
3. The ever-changing base pair sequence constitutes the diversity of DNA molecules, and the specific base pair sequence constitutes the specificity of each DNA molecule, which explains the reasons for biodiversity and specificity from the molecular level.
4. The transmission of genetic information is accomplished by the replication of DNA molecules, and the expression of genes is realized by controlling the synthesis of protein by DNA.
5.5 Unique double helix structure. DNA molecules provide accurate templates for replication; Accurate replication can be ensured by base complementary pairing. The proportions in the two complementary chains are mutual. In the whole DNA molecule, the sum of purine bases = the sum of pyrimidine bases. In the whole DNA molecule, the ratio is the same as that in each chain of the molecule.
6. Descendants are similar to their parents in character, because they have obtained copies of DNA copied by their parents.
7. Genes are DN fragments with genetic effects, which are arranged in a straight line on chromosomes, and chromosomes are the carriers of genes.
8. Because different genes have different sequences of deoxynucleotides (base sequences), different genes contain different genetic information.
The deoxynucleotide sequence in 9.9. DNA molecules determine the sequence of ribonucleotides in messenger RNA, which in turn determines the sequence of amino acids, and finally determines the specificity of protein's structure and function. Therefore, organisms can show various genetic characteristics. When protein synthesis is controlled by genes, the number of bases of genes: the number of bases on mRNA: the number of amino acids = 6: 3: 1. The codons of amino acids are three adjacent bases on messenger RNA, not bases on transport RNA. In the process of transcription and translation, the principle of base complementary pairing is strictly followed. Note: When pairing, A corresponds to U on RNA.
10. All genetic traits of organisms are controlled by genes. Some genes control metabolic processes by controlling the synthesis of enzymes. Another situation in which genes control traits is to directly affect traits by controlling the structure of protein molecules.
Biological variation of verb (abbreviation of verb)
(1) gene mutation
The concept of gene mutation: the change of gene structure caused by the addition, deletion or change of base pairs in DNA molecules.
② Characteristics of gene mutation: A. Gene mutation is ubiquitous in biology. B. gene mutation occurs randomly. C. the frequency of gene mutation is very low. D. most gene mutations are harmful to organisms. E. gene mutation has no directionality.
The significance of gene mutation: the fundamental source of biological variation, providing raw materials for biological evolution.
④ Types of gene mutation: natural mutation and induced mutation.
⑤ Application of artificial mutation in breeding: Artificial mutation can increase the frequency of mutation and greatly improve biological characteristics.
(2) Chromosome variation
Chromosome structural variation: deletion, addition, inversion and translocation, such as meow syndrome.
② Changes of chromosome number: including the increase or decrease of individual chromosomes in cells and the increase or decrease of genome forms.
(3) Genome characteristics: A. A genome does not contain homologous chromosome B, the chromosomes contained in a genome are different in morphology, size and function, and a genome contains a set of genes that control biological characteristics.
(4) Diploid or polyploid: an individual developed from a fertilized egg, and how many chromosomes are contained in a somatic cell is polyploid; Individuals developed from unfertilized germ cells (sperm or egg cells) are haploid (there may be 1 or more chromosomes).
⑤ Method of artificially inducing polyploid: Treating germinated seeds and seedlings with colchicine. Principle: When colchicine acts on dividing cells, it can inhibit the formation of spindle in the prophase of cell division, resulting in chromosome non-separation, thus doubling the number of chromosomes in cells.
⑥ Characteristics of polyploid plants: stout stems, relatively large leaves, fruits and seeds, and increased contents of nutrients such as sugar and protein.
⑦ haploid plant characteristics: the plant is weak and highly sterile. Haploid plants were obtained by retired anther culture. Haploid breeding significance: obviously shorten the breeding cycle (only two years).
Memory point:
1. Genome is a set of non-homologous chromosomes in cells, which are different in morphology and function, but the vector controls all the information of organism growth, development, heredity and variation. Such a set of chromosomes is called genome.
2. Genetic variation refers to the change of genetic material, including gene mutation, gene recombination and chromosome variation. The biggest feature of gene mutation is the production of new genes, that is, the genes at a certain point in the chromosome change.
Gene mutation is ubiquitous, random, low mutation rate, harmful to organisms, and mutation is not directional.
Gene mutation is the fundamental source of biological variation and provides the initial raw materials for biological evolution.
Gene recombination is the recombination of the original genes of an organism, which does not produce new genes, but recombines genes that are not in the same individual into an individual through hybridization.
Gene recombination through sexual reproduction provides an extremely rich source of biological variation, which is one of the important reasons for the formation of biodiversity and is of great significance to biological evolution.
The above variation is invisible to the microscope, but chromosome variation is the change of chromosome structure and quantity, which can be seen clearly by the microscope. This is the most important difference from the first two. Its changes involve chromosome changes, such as structural changes, number of individuals and ploidy changes, among which ploidy changes are of great significance in real life, resulting in a series of concepts and types such as genome, diploid, polyploid, haploid and polyploid breeding.
Six, human genetic diseases and eugenics
(1) eugenic measures: forbidding consanguineous marriage, conducting genetic counseling, advocating childbearing at appropriate age and prenatal diagnosis.
(2) Reasons for forbidding consanguineous marriage: Couples who are married by consanguineous relatives are much more likely to inherit the same pathogenic gene from their ancestors, and the probability of their children suffering from recessive genetic diseases is also greatly increased.
Memory point:
1. Polydactyly, syndactyly and achondroplasia are single-gene autosomal dominant genetic diseases; Vitamin D-resistant rickets is a single-gene X-chromosome dominant genetic disease. Albinism, phenylketonuria and congenital deafness are single-gene autosomal recessive genetic diseases; Progressive muscular dystrophy, red-green color blindness and hemophilia are recessive genetic diseases of single gene X chromosome. Cleft lip, anencephaly, essential hypertension and juvenile diabetes are hereditary diseases; In addition, autosomal diseases also include 2 1 trisomy syndrome and meow syndrome. Sex chromosome diseases include gonadal dysplasia.
Seven, cytoplasmic inheritance
① Characteristics of cytoplasmic inheritance: maternal inheritance (reason: almost all cytoplasm in fertilized eggs comes from mother cells); There is no certain segregation ratio in offspring (reason: during meiosis of germ cells, the genetic material in cytoplasm is randomly and unequally distributed to daughter cells).
② Material basis of cytoplasmic inheritance: There are DNA molecules in cytoplasm, mainly located in mitochondria and chloroplasts, which can control some characters.
Memory point:
1. Eggs contain a lot of cytoplasm, while sperm only contains a very small amount of cytoplasm, which means that almost all cytoplasm in fertilized eggs comes from eggs. In this way, the traits controlled by the genetic material in the cytoplasm are actually passed from the egg to the offspring, so the offspring always show the characteristics of the female parent.
2. The main characteristics of cytoplasmic inheritance are: maternal inheritance; There is no certain separation ratio in offspring. The reasons for the formation of cytoplasmic genetic characteristics are as follows: almost all cytoplasm in fertilized eggs comes from egg cells; In the process of meiosis, the genetic material in cytoplasm is randomly and unevenly distributed to egg cells. The material basis of cytoplasmic inheritance is DNA in chloroplasts, mitochondria and other cytoplasmic structures.
3. Nuclear inheritance and cytoplasmic inheritance are relatively independent. This is because, although there is no chromosome-like structure in cytoplasm, cytoplasmic genes, like nuclear genes, can replicate themselves and control the synthesis of protein through transcription and translation, that is, they are stable, continuous, variable and independent. However, nuclear inheritance and cytoplasmic inheritance are interactive, and in many cases they are the result of nuclear-cytoplasmic interaction.
Eight. Introduction to genetic engineering
The concept of (1) genetic engineering
Standard concept: in vitro, DNA molecules are artificially "cut" and "spliced" to transform recombinant biological genes, and then introduced into recipient cells for asexual reproduction, so that the recombinant cells can be expressed in recipient cells to produce gene products needed by human beings.
Popular concept: according to people's wishes, the individual genes of one organism are copied, transformed and transformed, and then put into the cells of another organism to directionally transform the genetic traits of that organism.
(2) Genetic manipulation tools
A. scissors of gene-restriction endonuclease (restriction endonuclease for short).
① Distribution: Mainly in microorganisms.
Functional characteristics: specificity, that is, recognizing specific nucleotide sequences and cutting specific tangents.
Results: sticky end (base complementary pairing) was produced.
B. gene needle and line -DNA ligase.
① Connection site: phosphodiester bond, not hydrogen bond.
Results: Two identical sticky terminals were connected.
C. transport vehicles with poor foundation-transport vehicles
Function: Send foreign genes into recipient cells.
(2) Conditions: A. It can be replicated in host cells and stably preserved. It has multiple restriction sites.
C, there are some marker genes
③ Species: plasmid, phage and animal and plant viruses.
Characteristics of Plasmids: Plasmids are the most commonly used vectors in genetic engineering.
(3) Basic steps of gene manipulation
A. extracting a target gene
Objective gene concept: specific genes that people need, such as human insulin gene, insect-resistant gene, disease-resistant gene, interferon gene, etc.
Select route:
B, combining the target gene with the vector
Using the same restriction endonuclease to cut the target gene and plasmid DNA (vector) respectively to make them produce the same sticky end, mixing the cut target gene with the cut plasmid, and adding an appropriate amount of DNA ligase to form a recombinant DNA molecule (recombinant plasmid).
C. introducing the target gene into the recipient cell.
Commonly used recipient cells: Escherichia coli, Bacillus subtilis, Agrobacterium tumefaciens, yeast, animal and plant cells.
D. detection and expression of target gene
The detection method is as follows: E.coli cells with antibiotic resistance genes in plasmids are put into corresponding antibiotics, and if they grow normally, the cells contain recombinant plasmids.
Expression: The recipient cells showed specific characteristics, indicating that the expression process of the target gene was completed. For example, after the insect-resistant cotton gene is introduced into cotton cells, the cotton bollworm is killed when eating cotton leaves; Insulin can be synthesized by introducing insulin gene into Escherichia coli.
(4) Achievements and development prospects of genetic engineering A. Genetic engineering and medical health B. Genetic engineering and agriculture, animal husbandry and food industry.
C. genetic engineering and environmental protection
Memory point:
1. As a vector, it must have the following characteristics: it can be replicated in host cells and stored stably; Having a plurality of restriction enzyme cutting points for connecting foreign genes; Plasmid is the most commonly used vector in genetic engineering, which exists in bacteria, yeast and other organisms and is a small circular DNA molecule that can replicate independently.
2. The general steps of genetic engineering include: ① extracting the target gene; (2) combining the target gene with the vector; ③ Introducing the target gene into the recipient cell; ④ Detection and expression of the target gene.
3. After the recombinant DNA molecule enters the recipient cell, the recipient cell must show specific characters, which can indicate that the expression process of the target gene has been completed.
4. Distinguish and understand commonly used vectors and commonly used receptor cells. At present, the commonly used vectors are plasmids, bacteriophages, animal and plant viruses, and the commonly used recipient cells are Escherichia coli, Bacillus subtilis, Agrobacterium tumefaciens, yeast and animal and plant cells.
5. Gene diagnosis uses DNA molecules labeled with radioisotopes and fluorescent molecules as probes, and uses the principle of DNA molecular hybridization to identify the genetic information of the detected samples, so as to achieve the purpose of detecting diseases.
6. Gene therapy is to introduce healthy foreign genes into gene-deficient cells to achieve the purpose of treating diseases.
Nine, biological evolution
(1) The content of natural selection theory is: over-reproduction, survival competition, gene variation and survival of the fittest.
(2) Species: refers to a group of individuals who are distributed in a certain natural area, have certain morphological structure and physiological functions, can mate and reproduce with each other in the natural state, and can produce fertile offspring.
Population refers to a group of individuals of the same species living in the same place.
Population gene bank: All genes contained by all individuals in a population.
(3) The basic viewpoint of modern biological evolution theory: population is the basic unit of biological evolution, and the essence of biological evolution lies in the change of gene frequency of population. Mutation, gene recombination, natural selection and isolation are three basic links in the process of species formation. Through their comprehensive effects, the population differentiates and eventually leads to the formation of new species.
(4) Mutation and gene recombination are raw materials for biological evolution. Natural selection changes the gene frequency orientation of population and determines the direction of biological evolution. Isolation is a necessary condition for the formation of new species (the formation of 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. Modern biological evolution theory with natural selection as the core holds that population is the basic unit of biological evolution, and the essence of biological evolution lies in the change of gene frequency of population. Mutation, gene recombination, natural selection and isolation are three basic links in the process of species formation. Through their comprehensive effects, the population differentiates and eventually leads to the formation of new species.
3. Isolation refers to the phenomenon that individuals of the same species and different populations cannot communicate freely under natural conditions, including geographical isolation and reproductive isolation. Its function is to block the gene communication between populations and make the gene frequency of populations develop in different directions in natural selection, which is a necessary condition and an important link for species formation.
4. The difference between speciation and biological evolution: biological evolution refers to the development and change of the same species, which can be long or short, with different degrees of character change. Any change in gene frequency, regardless of size, belongs to the scope of evolution. Only when the change of gene frequency breaks through the boundaries of species and forms reproductive isolation can the formation of species be established.
5. Every cell of an organism contains a whole set of genetic material of the species, and all the genes necessary to develop into a complete individual.
6. In organisms, cells do not show totipotency, but differentiate into different tissues and organs, which is the result of gene selective expression under specific time and space conditions.
Expand reading: first, based on teaching materials, lay a good foundation. Judging from the biological college entrance examination over the years, the content of the examination is about 60% of basic biological knowledge, basic skills and application ability of basic knowledge. To ensure that 60% of the basic scores can be scored at a high rate, it is necessary to read the textbooks carefully and master the knowledge of the textbooks. In the review stage, many students focus on doing problems instead of textbooks, hoping to make a "qualitative" leap in one or two exams or mock exams. This practice of giving up the basics is very dangerous and will eventually. Take notes on similar, confusing or closely related knowledge points in each chapter, and classify, compare and summarize them.
Second, attach importance to experimental operation and cultivate basic skills and innovative ability. According to statistics, the scoring rate of college entrance examination experimental questions is lower than the average score of the whole volume over the years. The reason for the low score rate is that students have not actually operated the experiment or really understood the principles and methods of the experiment. After the experiment, there is no process of returning to 100 million yuan and no analysis results.
Third, understand the chart and improve your ability. In recent years, in the two college entrance examinations, the chart questions accounted for a large score, and the chart questions became more and more complex and comprehensive, showing the phenomenon of multiple charts (tables) for one question, and charts and curves were integrated. Therefore, in preparing for the exam, we should attach great importance to textbooks or charts and curves closely related to textbooks. It is necessary to read, recognize and analyze pictures, strengthen the sense of image, and further raise perceptual knowledge to rational knowledge.
Fourth, do the questions carefully and draw inferences from others. Do after-school exercises, previous exercises and tests in the textbook. Do the questions carefully, sum up the knowledge points and problem-solving methods after finishing the questions, and draw inferences to sublimate the knowledge. When you do the problem, you can't abandon the foundation and do some difficult, biased and strange problems. At this point, students with poor foundation should be calm and sober.
Fifth, look at the catalogue and grasp it as a whole. The catalogue is the epitome and outline of the whole book. Reading the catalogue helps students to master the knowledge system of the whole book and improve their comprehensive application ability.