Heredity and evolution

How do humans know the existence of genes? Discovery of genetic factors

Where are the genes? The relationship between genes and chromosomes

What is a gene? The essence of genes

How do genes work? Gene expression

How do genes change during transmission? Gene mutation and other variations

How do humans use biological genes? From cross breeding to genetic engineering

How does the gene frequency change in the process of biological evolution? Modern biological evolution theory

Main line 1: the synthesis of the relationship among chromosomes, DNA, genes, genetic information, genetic codes and traits, with emphasis on the nature of genes;

Main line 2: the law of nuclear gene transfer with emphasis on separation phenomenon and its application synthesis;

Main line 3: The law of evolutionary variation with emphasis on gene mutation, chromosome variation and natural selection and its application synthesis.

Chapter 1 Discovery of Genetic Factors

Recessive traits of recessive genetic factors

Relative traits of heterozygotes separated by traits.

Dominant traits of dominant genetic factors

I. Introduction to Mendel

Second, the hybridization experiment (1)1956-1864-1872

1. Material selection: peas are self-pollinated.

Traits are easy to distinguish and stable and true inheritance.

2. Process: Orthogonality of a pair of related characters in artificial cross pollination.

P (parent) high stem dd× short stem DD reciprocal cross

F 1 (first generation) homozygote and heterozygote of high stem Dd

F2 (second generation) tall stem dd: tall stem Dd: short stem DD

The separation ratio of 1: 2: 1 is 3: 1.

explain

① Traits are determined by genetic factors. (Case-sensitive) ② Factors exist in pairs.

③ Each gamete pair contains only one factor. ④ Gamete combination is random.

4. Verify whether the test intersection (F 1) Dd X dd F 1 produces two kinds.

Gametes with height 1: 1 and height ratio 1: 1.

5. Separation phenomenon

In somatic cells of organisms, genetic factors controlling the same trait exist in pairs and do not merge; In the process of gametophyte formation, pairs of genetic factors are separated, and the separated genetic factors enter different gametes and are passed on to future generations with the gametes.

Third, the hybridization experiment (2)

1. yellow circle yyrr X green wrinkle yyrr

Yellow circle YyRr

Yellow circle Y_R_: yellow wrinkle Y_rr: green circle yyR_: green wrinkle yyrr parent combination

9: 3: 3: 1 recombination

2. The law of free combination

The separation and combination of genetic factors controlling different traits do not interfere with each other; During gamete formation, the paired genetic factors that determine the same trait are separated from each other, and the genetic factors that determine different traits are freely combined.

Four. Historical record of Mendel's genetic law

① Published on 1866 and rediscovered on 2 1900.

③ In 1909, Johnson renamed genetic factors as "gene" genotype, phenotype and allele.

△ genotype is the internal factor of trait expression, while phenotype is the expression form of genotype. Phenotype = genotype+environmental conditions.

Verb (abbreviation of verb) abstract

Description of segregation ratio of offspring traits

3: 1 heterozygote x heterozygote

1: 1 heterozygote x recessive homozygote

1: 0 homozygote x homozygote; Homozygote x dominant heterozygote

1.

2.

N pairs of genes hybridize with F 1 to form gamete number F 1, possible gamete combination number F2, genotype number F2 and phenotype number F2.

1

2

…… 2

four

…… 4

16

…… 3

nine

…… 2

four

…… 3: 1

9:3:3: 1

……

2n 2n 4n 3n 2n (3+ 1)n

Chapter II Relationship between Genes and Chromosomes

Foundation: Parallel relationship between gene and chromosome behavior, meiosis and fertilization.

Evidence of genes on chromosomes: Drosophila hybridization (white eyes) and sex inheritance: color blindness and VD rickets resistance

Modern explanation: Genetic factors are a pair of alleles on a pair of homologous chromosomes.

I. Meiosis

1. When sexually reproducing organisms produce mature germ cells, cells with half the number of chromosomes divide. During meiosis, chromosomes are copied only once, while cells divide twice. As a result of meiosis, the chromosome number of mature germ cells is reduced by half compared with that of primitive germ cells.

2. Process

Chromosome homologous chromosomes merge into centromere division

Sperm replicates primary tetrads (cross-exchange), and secondary monomers separate fine deformable sperm.

Cell spermatocyte separation (free combination) spermatocyte

Chromosome 2N 2N N 2N N N

DNA 2C 4C 4C 2C 2C C C

3. Homologous chromosome

A a Bb ① is the same in shape (centromere position) and size (length), and comes from parents and females respectively.

② A pair of homologous chromosomes is a tetrad, including two chromosomes and four chromatids.

③ Difference: homologous and non-homologous chromosomes; Sister and non-sister chromatids

④ Cross.

4. Judge the segmented image.

Odd minus Ⅱ or scattered germ cell central polarization

Chromosomes have no silk.

Paired front, middle and back

Even homologous chromosomes have reduced phase ⅰ.

Unfinished Ⅱ

Second, Sutton hypothesis.

1. Content: Genes are on chromosomes (chromosomes are the carriers of genes).

2. Basis: There is an obvious parallel relationship between gene and chromosome behavior.

① maintain integrity and independence in hybridization; ② exist in pairs.

(3) one from the father, one from the mother. ④ Free combination when gametophyte is formed.

3. Evidence: Sex-restricted inheritance of Drosophila melanogaster

Red eye XWXW X white eye XwY

XW Y red eye XWXw

Red eye XWXw: red eye XWXW: red eye XW Y: red eye XwY

① There are multiple genes on one chromosome; ② Genes are arranged linearly on chromosomes.

4. Modern interpretation of Mendel's genetic law

(1) Segregation: Alleles are passed on to offspring independently with the separation of homologous chromosomes.

② Law of free combination: Non-alleles on non-homologous chromosomes can be combined freely.

Third, the characteristics and judgment of sex-linked inheritance

Examples of genetic modes and characteristics of genetic diseases

Keywords atavism of autosomal recessive genetic disease, patients with recessive homozygous albinism, phenylketonuria,

Autosomal dominant genetic diseases are passed down from generation to generation. Normal people are recessive homozygotes with multiple/syndactyly and achondroplasia.

There are more male patients than female patients with atavism, X chromosome recessive genetic disease, cross inheritance, color blindness and hemophilia.

Dominant genetic diseases with X chromosome are passed down from generation to generation and cross-inherited. Women are more resistant to VD rickets than men.

Hereditary diseases with Y chromosome are transmitted from men to women, and only male patients have no hair ears.

Fourthly, the judgment of gene map.

Key to pathogenic genes

A 1 has atavism. ..................................................................................................................................................................

B 1 Regardless of sex (the incidence of male and female is equal) ....................................................................................................................................................

B2 is related to gender.

C 1 Men are all patients with ...............................................................'s Y chromosome.

C2 males have more X chromosomes than females.

There is no atavism (generational occurrence) .....................................................................................................................................................................

D 1 has nothing to do with sex.

D2 is related to gender.

All men are patients. ........................'s Y chromosome.

In E2 area, there are more women than men (about twice as many as men). .............................................................................................................................................................

Chapter III Nature of Genes

Transformation experiment of pneumococcus

evidence

The bacterial test gene infected by phage is a DNA fragment with genetic effect;

Gene is the most basic unit to control biological characters;

The structural essence of double helix DNA, in which four deoxynucleotides are arranged smoothly.

Genetic information expressed by sequence.

Replication of semi-reserved DNA

First of all, DNA is the main genetic material.

1. Transformation experiment of pneumococcus

(1) in vivo transformation 1928 Griffith, England

① Living R, non-toxic live mice.

② Live rats, poisonous rats and dead rats; Isolate live s

③ The killed S is a non-toxic live mouse.

④ S was killed by living R+△, but it was not toxic to dead rats; Isolate live s

What is the transformation factor?

(2) 1944 in vitro transformation of American Avery.

Polysaccharide or protein R type

In vivo S DNA+R medium r type +S type

DNA hydrolysate r form

The transforming factor is DNA.

2. Electron microscopic observation and isotope tracing test of bacteriophage infected bacteria 1952 Hershey and Cai Ming.

32P-labeled DNA

35S-labeled protein DNA has continuity and is genetic material.

3. The experimental RNA of tobacco mosaic virus is also genetic material.

Second, the molecular structure of DNA.

1. nucleotides nitrogenous bases: a, t, g, c, u.

Pentose phosphate: ribose, deoxyribose

2. 1950 Pauling 195 1 year Wilkins+Franklin 1952 Chagov

3.3 structure. Deoxyribonucleic acid

① (right hand) double helix

② skeleton

③ Pairing: A = T/U

G = C

4. Features

① Stability: The sequence of alternating arrangement of deoxyribose and phosphoric acid is stable.

② Diversity: The sequences of base pairs are different.

③ Specificity: Each DNA has its own unique base pair sequence.

calculate

1. The ratio of two complementary chains is mutual.

2. In the whole DNA molecule, the sum of purine bases = the sum of pyrimidine bases.

3. In the whole DNA molecule, the ratio is the same as that of each chain in the molecule. Third, the replication of DNA.

1. location: nucleus; Time: the interval of cell division.

2. Features: ① semiconservative replication with edge retreating.

3. Basic conditions: ① template: two single-stranded DNA molecules that begin to melt;

② Raw materials: free deoxynucleotides in nuclear fluid.

③ Energy: provided by ATP hydrolysis;

④ Enzyme: Enzyme refers to an enzyme system, not just helicase.

4. Significance: To transmit genetic information from parents to offspring, so as to maintain the continuity of genetic information.

4. Genes are DNA fragments with genetic effects.

Genes are DNA fragments, which are distributed discontinuously on DNA and separated by base sequences.

It can control traits and has specific genetic effects.

△ Gene structure of prokaryotic and eukaryotic cells

① Contact information: coding area+non-coding area

(2) Prokaryotes: The coding region is continuous without interval.

Eukaryote: The coding region can be divided into exons and introns, so it is discontinuous and discontinuous.

Chapter IV Gene Expression

There is genetic effect in controlling mRNA protein.

Protein structure characteristics of DNA fragments affect the environment.

It is to control the synthesis of biological enzymes and control metabolism.

Basic unit center principle

1. gene directs the synthesis of protein.

1. transcript

(1) The process of synthesizing mRNA using one of the DNA double strands in the nucleus as a template.

(2) ① The messenger (mRN A) that transmits the genetic information in the gene to protein is chain-shaped;

Rna (2) Transport RNA(tRNA), clover structure, recognizing genetic code and carrying specific amino acids;

(Single-stranded) ③ Ribosomal RNA(rRNA) is RNA in ribosomes.

(3) Process (location, template, conditions, raw materials, products, destination, etc. )

2. Translation

(1) On the ribosome of cytoplasm, protein with a certain amino acid sequence was synthesized using mRNA as a template.

(2) Essence: The base sequence in mRNA is translated into the amino acid sequence of protein.

(3)(64) Codon: Three adjacent bases on mRNA that determine amino acids.

Where AUG, this is the starting password; UAG, UAA and AGA are termination passwords.

(4) Genetic information

① Narrow sense: deoxynucleotide sequence that controls genetic traits in genes.

② Wide: The signals obtained by offspring from their parents to control genetic traits are expressed by deoxynucleotide sequences of DNA on chromosomes.

③ Central rule:

(5) Translation process

Third, gene control of traits.

1.

Protein of DNA RNA (trait)

Deoxynucleotide sequence ribonucleotide sequence amino acid sequence

Genetic information genetic code

2. The relationship among genes, protein and traits.

(1) gene controls the metabolic process by controlling the synthesis of enzymes, and then controls biological characters, such as albinism.

(2) Genes can also directly control the characters of organisms by controlling the structure of protein, such as sickle cell anemia.

Gene mutation and other variations

inherited

Mutation, chemical and biological mutation breeding of mutant genes

Genetic recombination hybrid breeding

Chromosome variation polyploid and haploid breeding

I. Gene mutation

1. Definition: Changes in gene structure caused by substitution, addition and deletion of base pairs in DNA molecules.

2. Time: In the process of DNA replication between mitosis or the first meiosis.

External factors: physical, chemical and biological factors. Internal factors: variability.

4. Features: ① universality ② randomness, directionless ③ low frequency ④ harmfulness.

5. Significance: ① The origin of new genes ② The basic source of variation ③ The original materials of evolution.

6. For example: sickle cell anemia

Second, gene recombination.

1. Gene recombination controlling different traits during sexual reproduction.

2. Time: the prophase or anaphase of meiosis.

2. Significance: ① Generation of new genotypes ② One of the sources of biological variation ③ Significance to evolution.

Third, chromosome variation.

1. 19 17 Drosophila meow syndrome without carved wings.

Structural variation repeats the rod-shaped wings of Drosophila in 19 19.

Translocation 1923 chronic myeloid leukemia

Inverted horizon

Variation of quantitative structure: individual chromosome; Increase or decrease of genome

2. Genome

A group of non-homologous chromosomes with different shapes and functions in cells carry all genetic information that controls the growth, development, inheritance and variation of organisms. For example, human is 22 constant +X or 22 constant+y.

△ Karyotype (Karyotype) refers to the number, size and morphological characteristics of all chromosomes of a biological cell species; Such as: human karyotype: 46, XX or XY.

3.

Diploid female gamete

Haploid direct development zygote organism

Polyploid male gamete (colchicine)

Fourth, human genetic diseases.

1. autosome

Recessive gene sickle anemia, albinism, congenital deaf-mute red-green color blindness

Monogenic genetic disease dominant genes polydactyly, syndactyly and achondroplasia resist VD rickets.

Polygenic genetic diseases: essential hypertension, coronary heart disease, asthma, juvenile diabetes.

Chromosome abnormality: 2 1 trisomy syndrome

2. Premarital examination and genetic counseling.

Monitoring and prevention of prenatal diagnosis: amniotic fluid, B-ultrasound, maternal blood cell examination, gene diagnosis.

3. Human Genome Project (HGP): All genetic information carried by human DNA.

① Proposal: 1986 American biologist Du Bailey.

② Main contents: Draw four maps of human genome: genetic map, physical map, sequence map and transcription map.

③ 1990 10.

④ China participated in the explanation of 30 million bases on the short arm of chromosome 3, accounting for 1%.

⑤ On June 20th, 2000, the working sketch was preliminarily completed.

⑥200 1 February, sketch publishing ⑥ completed successfully in 2003.

△ lineal blood relatives refer to pushing up three generations from themselves and pushing down three generations; ,

△ Collateral blood relatives refer to other relatives born in the same blood as grandparents except immediate family members. △ Gene diagnosis uses DNA molecules labeled with radioisotopes and fluorescent molecules as probes and uses the principle of DNA molecular hybridization.

Identify the genetic information of the detected samples to achieve the purpose of detecting diseases. △ Gene therapy is to introduce healthy foreign genes into gene-deficient cells to achieve the purpose of treating diseases.

Chapter VI Breeding Methods

monoploid

Selection breeding, cross breeding, mutation breeding and polyploid transgenic.

First, compare the culture in No.4 Middle School.

Conventional breeding, mutation breeding, polyploid breeding and haploid breeding.

Processing P F 1 F2

Using radiation, laser,

Chemical treatment with colchicine.

In vitro culture of anthers of germinated seeds or seedlings

Principle gene recombination,

Artificial induced combination of excellent trait genes

Mutation destroyed the formation of spindle,

The doubling of chromosome number induces the direct development of pollen,

Use colchicine again

excellent

lack

The dot method is simple,

Very predictable,

However, the long cycle accelerates breeding and improves traits, but there are not many beneficial individuals and a large number of organs and nutrients need to be treated.

High content, but slow development, low seed setting rate and shortened breeding cycle,

But this method is very complicated,

The survival rate is very low

Examples of Rice Breeding Breeding Breeding of Seedless Watermelon Plants with High Penicillin Yield

Second, genetic engineering.

Scissors for extracting target gene: restriction endonuclease

The combination of target gene and vector: plasmid, phage and virus.

The target gene was introduced into recipient cells: Escherichia coli, Bacillus subtilis, Agrobacterium tumefaciens, yeast and cells.

Detection and expression of target gene: The recipient cells showed specificity.

Chapter VII Evolution Theory

Lamarck: Utilization, Consumption, Acquired Inheritance

Darwin: Survival of the fittest, elimination of the unfit (natural selection theory)

Basic unit: population

Essence: the change of gene frequency

Raw materials: mutation and recombination

Modern evolutionism forms species and determines the direction: natural selection.

Necessary conditions: isolation

Biodiversity: Genes, Species and Ecosystems

Synergy (brutal competition versus co-evolution) neutral theory (accident versus necessity)

Supplement punctuated equilibrium's catastrophe theory (gradual versus sudden) (gradual versus sudden)

I. Biological evolution

Study the general laws of the historical development of biology, such as

The emergence and development of the biological world: the origin of life, species and human beings

Evolutionary mechanism and theory: heredity, variation, direction and speed

The relationship between evolution and environment ④ The history of evolution: schools and debates.

Second, the origin of modern evolutionary theory

1. creationism+species invariance theory (creationism)

2. French Lamarck 1809 Animal Philosophy

(1) creatures evolved from ancient creatures; (2) Gradually evolving from low to high.

③ The formation of biological adaptive characteristics is due to utilization, exclusion and acquired inheritance.

3. British Darwin's theory of natural selection in the Origin of Species 1859.

Overreproduction and population constancy+limited living conditions

Survival competition+heredity and variation

Natural selection, survival of the fittest+acquired inheritance.

New organism

4. Modern evolutionism: taking the theory of natural selection as the core content.

Third, the content of modern evolutionary theory

Keywords mutant allele, sexual reproduction gene recombination, no directional mutation, small favorable mutation selection

Multiple selection and genetic accumulation are of great benefit to the change of mutation gene frequency and the directional evolution of new species.

Basic viewpoint: population is the basic unit of biological evolution, and the essence of biological evolution is 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 action, the population differentiates and eventually leads to the formation of new species. In this process, mutation and gene recombination produce 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.

4. Species: A group of organisms that can mate with each other under natural conditions and produce fertile offspring.

A small population (producing many varieties) and a new species.