The first chapter close to the cell
1. (2) From small to large, the structural levels of life systems are: cells, tissues, organs, systems, individuals, populations, communities, ecosystems and biospheres.
Among them, it is very important to distinguish between population, community and ecosystem. A population is all individuals of the same organism in a certain area; Community is all living things in a certain area, including plants, animals and microorganisms; Ecosystem is the sum of all living and inorganic environments in a certain area.
2.(b) Use a high-power microscope. How to use a microscope, it is important to use a high-power mirror. Common test sites include: the steps of replacing the high-power lens (moving the object image to the center, rotating the converter, dimming and adjusting the focusing screw), the changes of the object image after replacing the high-power lens (the object image becomes larger, the field of view becomes smaller and the field of view is darker than before), and the problem of slide movement.
3.(b) Scientists divide cells into prokaryotic cells and eukaryotic cells according to the nuclei wrapped by nuclear-free membranes:
Unity of differences
An unformed nucleus of a prokaryotic cell (nuclear-free membrane-pseudonucleus)
Chromosome-free (only circular DNA)
There is only one kind of organelle-ribosome 1. They all have cell membranes and cytoplasm.
2. Both contain DNA.
3. Everyone has ribosomes.
Eukaryotic cells have a shaped nucleus (with a nuclear membrane)
There are chromosomes (protein on DNA)
There are many kinds of organelles.
The cell wall of prokaryotic cells does not contain cellulose and pectin, but mainly peptidoglycan.
Cell membranes are similar to eukaryotes.
4. (1) Differences between prokaryotes and eukaryotes: Prokaryotes include bacteria, cyanobacteria, mycoplasma, chlamydia and actinomycetes. (Memory formula: blue sweater)
Among them, fungi (yeast, mold, mushrooms, etc. ) and algae (Chlamydomonas, etc. ) is often difficult to distinguish in eukaryotes.
5. (1) Cyanobacteria: Prokaryotes are autotrophic because they can carry out photosynthesis (but there are no chloroplasts, no mitochondria, etc.). ), and there is only one kind of organelle ribosome with a layer of cell wall outside (many prokaryotes have it, but its composition is different from that of plant cell wall).
6. (1) Cell theory reveals the unity of cells and biology.
7. (1) Cell is the most basic life system and the basic unit of organism structure and function.
Note: The virus has no cell structure and belongs to neither eukaryote nor prokaryote, and its nutritional mode is parasitism.
8.(A) From biosphere to cell, life systems are interdependent at different levels, and each system has its own specific composition, structure and function.
Chapter II Molecules Constituting Cells
1, (a) Macroelements and trace elements that constitute organisms and their important functions.
1, a large number of elements: CHON (basic element) CHONPS (main element) KCaMg
The most basic element of an organism is c; The element that makes up most organisms is O.
Biological macromolecules are based on carbon chains, so "C is the core element of life"
2. Trace elements: essential elements for organisms, but the required amount is very small.
For example, when plants lack B (element), anther filaments contract and pollen development is poor. (flashy)
3. The types of chemical elements that make up organisms are basically the same, but the element contents of different organisms are quite different.
4. There are:
Unity: the elements that make up an organism can be found in inorganic nature, and no element is unique to an organism.
Difference: The content of elements that make up an organism is very different between organisms and inorganic nature.
2.(b) Compounds constituting cells
Inorganic substances: ① water (about 60-95%, which is the most abundant compound in all living cells) ② inorganic salts.
Organic matter: ③ sugars ④ nucleic acids ⑤ lipids.
⑥ protein (the most abundant organic substance in all living cells and the most abundant compound in stem cells).
3.(b) Identification of reducing sugar, fat and protein in biological tissues.
(1) Reducing sugar (glucose, fructose, maltose)+phenanthrene → light blue brown brick red precipitate.
(1) Before being added to the sample solution, Solution A and Solution B in Linfei reagent must be evenly mixed in the same amount, and the sample solution is now ready for use.
(2) It must be heated in a water bath (50-65℃).
(2) Fat was dyed orange by Sudan III; Dyed red by Sudan IV, commonly used materials: peanut cotyledons or sunflower seeds.
(3) Common materials for purple reaction between protein and biuret: egg white, soybean tissue sample solution and milk.
Precautions: ① Add 2ml of solution A first, and then add 3 ~ 4 drops of solution B. Do not heat it.
② Before identification, set aside some tissue sample solutions for comparison.
4.(c) The chemical structure, basic units and functions of protein.
Protein consists of C, H, O, N elements, and some contain S.
① Basic unit: structural characteristics of about 20 amino acids: each amino acid contains at least one amino group and one carboxyl group, and they are all connected to the same carbon atom. General structural formula:
The types of amino acids are determined by R groups (side chain groups).
② peptide bond: it is formed by dehydration and condensation of amino acids, and its molecular formula is -CO-NH-
③ Correlation calculation: dehydration number = peptide bond number = amino acid number n–chain number m.
Protein molecular weight = amino acid molecular weight ╳ number of amino acids–dehydration ╳ number 18.
The minimum value of amino group or carboxyl group in single-chain protein is1; The minimum value of amino group or carboxyl group in m peptide chain is m.
④ Reasons for the molecular diversity of protein: The variety, quantity and arrangement order of amino acids that make up protein, as well as the spatial structure of peptide chains lead to the structural diversity of protein. The structural diversity of protein leads to the functional diversity of protein.
⑤ Function: 1 Some protein are important substances that constitute cells and organisms. 2 catalysis, that is, enzyme.
3 transport, such as hemoglobin transport, oxygen 4 regulation, such as insulin and growth hormone.
5 immune functions, such as antibodies
⑥ protein is the undertaker of life activities.
5.(b) Chemical composition and basic unit of nucleic acid
Nucleic acid consists of carbon, hydrogen, oxygen, nitrogen and phosphorus.
① Basic unit: nucleotide
Structure: one molecule of phosphoric acid, one molecule of five-carbon sugar (deoxyribose or ribose),
One molecule of nitrogenous bases (there are five kinds) A, T, C, G and U.
Deoxyribonucleic acid (DNA): mainly exists in the nucleus, including four bases (A, T, C, G), and the basic unit is four deoxynucleotides.
Ribonucleic acid (RNA): mainly exists in cytoplasm, including four bases (A, U, C, G), and the basic unit is four ribonucleotides.
The nucleic acid * * * has five bases and eight nucleotides.
③ Function: It has genetic function and is closely related to the genetic variation of organisms and the synthesis of protein.
6. (1) Among the dyes of Pyrone Red and Methyl Green, Methyl Green can make DNA appear green, and Pyrone Red can make RNA appear red.
In this experiment, the role of hydrochloric acid is to change the permeability of membrane and accelerate the entry of pigment into cells.
Taking human oral epithelial cells as experimental materials, the experimental steps are slicing, hydrolysis, smear washing, staining and observation.
7. Important sugars and lipids in animals and plants and their functions
1, (b) Carbohydrates C, H and O are the main energy substances.
Category: ① monosaccharides: glucose (an important energy source), fructose, ribose & etc. Deoxyribose (constituting nucleic acid), galactose
2 disaccharides: sucrose and maltose (plant); Lactose (animal)
③ Polysaccharides: starch and cellulose (plant); Glycogen (animal)
Disaccharide and polysaccharide are formed by dehydration and connection of two or more monosaccharides.
Seven energy sources: ① important energy source: glucose ② main energy source: sugar ③ direct energy source: ATP.
④ Basic energy: sunlight ⑤ Energy storage substance of plant cells: starch.
⑥ Energy storage substance of animal cells: glycogen ⑥ Biologically good energy storage substance: fat.
2. (1) Lipids are composed of C, H and O, and phospholipids contain P.
Classification: ① fat ② phospholipid: an important component of membrane structure (cell membrane, vacuole membrane, mitochondrial membrane, etc.). )
③ Sterols: including cholesterol, sex hormones and vitamin D;
8. (1) Polysaccharide, protein and nucleic acid are all biological macromolecules, also called multimers, and their basic unit is called monomer. The monomer that constitutes polysaccharide is called monosaccharide, the monomer that constitutes protein is called amino acid, and the monomer that constitutes nucleic acid is called nucleotide.
9. (a) The existing forms of water in cells and the significance of water to living things.
1, bound water: It combines with other substances in the cell and is an integral part of the cell structure.
2. Free water: mostly, physiological functions: ① good solvent; ② Transport nutrients and metabolic wastes; ③ The raw materials of many biochemical reactions in cells, such as photosynthesis of plants, need the participation of water.
3. The greater the ratio of free water to bound water, the more active the metabolism.
10, (1) the importance of inorganic salt ions to organisms
1, an important component of some complex compounds in cells. For example, Fe2+ is the main component of hemoglobin; Mg2+ is an important component of chlorophyll.
2. Maintain cell life activities (including cell morphology, osmotic pressure and acid-base balance).
If the blood calcium content is low, it will twitch.
Chapter III Basic Structure of Cells
1, (b) the submicroscopic structure patterns of animal cells and plant cells (page 46)
2. (1) Structure and function of cell membrane
Chemical composition: protein and lipid (phospholipid) molecules, and a small amount of sugar.
Structure: The phospholipid bilayer is the basic skeleton, embedded in the middle, penetrating and wrapping protein.
Features: The structural feature is certain fluidity, and the functional feature is selective penetration.
Phenomena that can prove the fluidity of cell membrane: phagocytosis, deformation movement of amoeba, fusion experiment of human and mouse cells, etc.
Functions: 1, protection of cell interior 2, exchange of transport substances 3, intercellular recognition, immunity (related to cell glycoprotein)
Experimental material for preparing pure cell membrane: mature red blood cells of mammals.
3.(a) Function of cytoplasmic matrix: It is the main site for metabolism of living cells.
(A) the basic structure and main functions of mitochondria and chloroplasts
Mitochondria: (both animals and plants), rich in functions. It has a double-layer membrane structure, and the inner membrane protrudes inward to form a "ridge". There are enzymes related to aerobic respiration on the matrix and particles of the inner membrane, which is the place for the second and third stages of aerobic respiration. 95% of the energy of the living body comes from mitochondria. Contains a small amount of DNA and RNA.
Chloroplast: Only exists in mesophyll cells of plants. Double membrane structure. There are pigments on the substrate, and the substrate and the substrate contain enzymes related to photosynthesis, which is the place of photosynthesis and can synthesize sugars. Contains a small amount of DNA and RNA.
5. (b) Comparison of organelle knowledge
Distribution of chloroplasts and vacuoles in plant-specific organelles
The unique organelle centrosome of animals and lower plants (related to cell mitosis)
The organelle ribosome (the synthesis site of protein) found in eukaryotic cells and prokaryotic cells.
The organelles with monolayer membrane structure include endoplasmic reticulum, vacuole, lysosome and Golgi apparatus.
Mitochondria and chloroplasts of organelles have double membrane structures.
Ribosomes and centrosomes of organelles without membrane structure
Chloroplasts and vacuoles of organelles containing pigments.
Cell organelles, mitochondria and chloroplasts are related to energy conversion.
The organelles (structures) related to protein secretion include ribosomes, endoplasmic reticulum, Golgi apparatus, (cell membrane) and mitochondria.
Golgi apparatus, organelles with the same shape but different functions in animal and plant cells (plant cells are related to the formation of cell walls; Animal cells are related to the formation of secretions)
There are no organelles such as chloroplasts, centrosomes and vacuoles in apical meristem.
Organelle ribosomes (synthetic carriers) and mitochondria (providing energy) related to active transport.
Another name for various organelles.
Don't call it energy conversion protein.
Processed vegetable protein
Assembler organic matter
Synthetic workshop unit
Enzyme warehouse cell
Storage of water and salt
Light energy conversion station power plant
Organelle chloroplast mitochondria Golgi body ribosome endoplasmic reticulum lysosomal vacuole
Organelles that can produce water and their corresponding physiological functions;
Cell organelle name Physiological function of cell type
Ribosome condensation of animals and plants
The third stage of aerobic respiration of mitochondrial animals and plants
Dark reaction of photosynthesis in chloroplast plants
ATP-producing structure and its corresponding physiological function;
Structural Name Physiological Function of Cell Types
The first stage of anaerobic respiration or aerobic respiration of animals and plants in cytoplasmic matrix
The second and third stages of aerobic respiration in mitochondrial animals and plants
Photoreaction of photosynthesis in chloroplast plants
Organelles related to cell mitosis and their corresponding physiological functions;
Physiological function of organelles in naming cell types
Synthesis of ribosome-related proteins between animal stage and plant stage.
Early spindle formation in centrosomes and lower plants
Formation of cell wall in Golgi plants at the end stage
Mitochondrial animals and plants provide energy throughout the period.
6. (1) Experiment in this chapter: Observing the flow of cytoplasm can be marked by the movement of chloroplasts in the cytoplasm matrix.
7. (1) biofilm system's concept: Cell membrane, nuclear membrane and membranes of various organelles make up the biofilm system.
Various biomembranes are not only related in structure, but also in function.
8.(a) The cell wall is completely permeable and consists of cellulose and pectin.
9.(b) Structure and function of eukaryotic cell nucleus
1. Structure: Eukaryotic cell nucleus includes nuclear fluid, nuclear membrane (with nuclear pores), nucleoli and chromatin.
① The nuclear membrane is composed of a double-layer membrane with nuclear pores, which is the channel for material exchange and information exchange between the nucleus and cytoplasm.
② Nucleoli are related to the synthesis of some RNA and the formation of ribosomes.
③ Chromatin is mainly composed of DNA and protein, which can be dyed dark by alkaline dyes. During mitosis, chromatin is filamentous; Chromatin spirals into a cylindrical or rod-shaped chromosome during mitosis, so chromatin and chromosome are two forms of the same substance in cells at different times.
2. Function: It is the place where genetic materials are copied and stored, and it is the control center of cell metabolism and heredity.
Chapter IV Material Input and Output of Cells
1, (b) the principle of osmosis, water absorption and water loss of cells.
1, osmotic water absorption conditions: there is a semi-permeable membrane, and the solution on both sides of the membrane has concentration difference.
Water molecules or other solvent molecules, but not solute molecules, diffuse in the process of osmosis.
2. Protoplast: cell membrane, vacuole membrane and cytoplasm between the two membranes.
3. Plant protoplasm is a selectively permeable membrane. When there is concentration difference inside and outside the membrane, cells absorb (lose) water.
Principle: whoever has high concentration will have water.
4. The separation between plasma and wall is an important experimental site. ① Causes (the internal cause is that the protoplasm layer is more flexible than the cell wall, and the external cause is the poor concentration), ② Conditions (living mature plant cells), ③ Application (identifying whether it is a living cell; (4) Phenomena (vacuole becomes smaller, cell fluid concentration becomes darker, protoplasm layer is separated from cell wall).
2, (a) the way in and out of the cell membrane:
1, free diffusion: high concentration is transported to low concentration without carrier and energy (water, CO2, O2, N2, ethanol, glycerol, benzene, fatty acids and vitamins).
2. Auxiliary diffusion: high concentration is transported to low concentration, which requires a carrier and does not require energy (red blood cells are often tested to absorb glucose).
3. Active transportation: Transportation from low concentration to high concentration requires carriers and energy. (mainly nutrition and ion absorption, often test the absorption of amino acids and glucose in the small intestine; Red blood cells absorb potassium ions and roots absorb mineral ions)
4. Phagocytosis and vomit cells: The way of macromolecular substances entering and leaving cells requires energy, and no carrier is needed, which proves the fluidity of cell membrane.
Chapter V Energy Supply and Utilization of Cells ★ (Read and write the questions carefully)
1, (b) The concept of enzyme: a kind of organic matter with biocatalysis produced by living cells (most enzymes are protein, and a few are RNA). As long as the conditions are right, it can work inside and outside the cell.
2. (3) Characteristics of the enzyme: ① specificity
② High efficiency (compared with inorganic catalysts, enzymes have a more significant effect on reducing activation energy, so the efficiency is high).
③ Appropriate temperature and PH are needed for enzyme catalysis: if the temperature and pH are too high or too low, the activity of enzyme will be obviously reduced. In fact, peracid, overbase and high temperature will destroy the molecular structure of enzyme and make it lose its activity. High temperature inactivates the enzyme; Low temperature reduces the enzyme activity, and it can be restored at a suitable temperature.
Pepsin can only catalyze in acidic environment (optimum pH = 2). Trypsin can only work in alkaline environment (optimum pH=7.8).
(B)ATP: the role of adenosine triphosphate: the direct source of energy needed for metabolism.
Structural formula: A-P ~ P ~ P, where a stands for adenosine, p stands for phosphate group, and "~" stands for high-energy phosphate bond. The content of ATP in living cells is very small, and the content of ATP has been in a dynamic equilibrium state, which is far from the break of phosphate bond of A during hydrolysis.
4. (b) Mutual transformation between ATP and ADP
ATP←→ADP+Pi+ energy (irreversible)
The equation goes from left to right, and energy represents released energy, which is used in all life activities.
When the equation goes from right to left, energy represents the transferred energy. In animals, the energy transmitted by respiration is mainly located in mitochondria. In plants, chloroplasts and mitochondria are responsible for photosynthesis and respiration respectively.
★★★★ Photosynthesis
1, equation: CO2+H2O18 —→ (CH2O)+O218.
Note: All oxygen released by photosynthesis comes from water.
2. Pigment: It includes chlorophyll and carotenoid, and the pigment is distributed on thylakoid membrane.
Pigment distribution map:
Pigment extraction experiment: acetone extracts pigment;
Silicon dioxide makes grinding more thorough.
Calcium carbonate prevents pigment from being destroyed.
Experimental principle: Pigment in green leaves can be dissolved in chromatographic solution, and the solubility in chromatographic solution is different, and the high solubility spreads rapidly on filter paper with chromatographic solution.
Chlorophyll mainly absorbs red light and blue-violet light, while carotenoids mainly absorb blue-violet light. Photosynthesis is strongest in white light, followed by red light and blue-violet light, and weakest in green light.
3.★ Photoreaction stage
Setting: Conditions of chloroplast thylakoid membrane: there must be light, pigment and photosynthetic enzyme.
Steps: ① photolysis of water, that is, decomposition of water into oxygen and reduction of hydrogen 2h2o-→ 4 [h]+O2 =
②ATP is generated, ADP and Pi receive light energy and become ATP.
Energy change: Light energy becomes active chemical energy in ATP.
4, ★ dark reaction stage
Setting: Chloroplast substrate conditions: light or no light, carbon dioxide, energy, enzyme.
Steps: ①CO2 is fixed, and CO2 and C5 combine to generate two C3's.
(2) C3 reduction, accepting the reduced hydrogen, enzyme and ATP to generate C5 and (CH2O).
Energy change: ATP active chemical energy is converted into stable chemical energy in the compound.
Relationship: Photoreaction provides ATP and [H] for dark reaction.
5.★ Factors affecting photosynthesis
⑴ Effect of light intensity on photosynthesis: The photosynthesis intensity of plants is within a certain range.
It increases with the increase of light intensity, but when the light intensity reaches a certain level, it is restricted by other conditions.
The intensity of photosynthesis no longer increases with the increase of light intensity.
Meaning of each point: A represents the amount of CO2 released by respiration when the intensity of photosynthesis is 0;
B indicates that the intensity of photosynthesis is equal to the intensity of respiration; C stands for the light intensity at point C.
Photosynthesis is maximized.
(2) Low temperature affected the activity of enzymes and the photosynthetic rate was low. With the increase of temperature,
When the photosynthetic rate is accelerated, too high temperature will affect the activity of enzymes and the photosynthetic rate will decrease. produce
Increase the temperature during the day, enhance photosynthesis, lower the room temperature at night, and inhibit the accumulation of respiration.
Tired organic matter.
(3)CO2 concentration: In a certain range, the photosynthesis intensity of plants increases with the increase of CO2 concentration.
But after reaching a certain concentration, the intensity of photosynthesis no longer increases. in production
Make the site well ventilated and provide sufficient CO2.
(4) Water supply: When the leaves of plants are short of water, the stomata will be closed to reduce water.
At the same time, the loss of carbon dioxide affects the entry of carbon dioxide into leaves, the dark reaction is blocked, and photosynthesis is reduced.
Plants have a lunch break. Irrigation should be done in time during production to ensure plant growth.
C3 C5 [H] ATP
Carbon dioxide concentration = = ↓↓↓
Carbon dioxide concentration Ⅳ
Light intensity = ↓ =
luminous intensity
The required moisture.
Summary:
6. Significance: ① Making organic matter; ② converting and storing solar energy; ③ Maintain the relative stability of CO2 and O2 in the atmosphere.
6. Respiratory function
1, setting: anaerobic respiration in cytoplasmic matrix; The first stage of aerobic respiration is in the cytoplasmic matrix, the second stage is in the mitochondrial matrix, and the third stage is in the mitochondrial inner membrane.
2. Anaerobic respiration: The first stage of anaerobic respiration is exactly the same as the first stage of aerobic respiration.
The total reaction formula is: C6H 12O6CO2+2C2H5OH (alcohol)+a little energy (plant cells, yeast).
C6H 12O6 2C3H6O3 (lactic acid)+a little energy (animal, human, potato tuber cell, beet tuber)
A small part of the energy produced by anaerobic respiration is used to produce ATP, and most of it is stored in lactic acid or alcohol.
3. Aerobic breathing:
Step 1: 1 molecule of glucose is decomposed into 2 molecules of pyruvate, [H] and a small amount of energy (in the cytoplasmic matrix).
Step 2: Pyruvate combines with water to generate CO2, [H] and a small amount of energy (in mitochondrial matrix).
Step 3: [H] in the first two steps combines with inhaled oxygen to generate water and a lot of energy (on the inner membrane of mitochondria).
Part of the energy released by aerobic respiration is used to produce ATP, and most of it is lost in the form of heat energy.
4. Summary:
① When the same amount of glucose is consumed, the ratio of CO2 produced by anaerobic respiration to CO2 produced by aerobic respiration is1:3;
② If the amount of CO2 produced by the organism is equal to the amount of O2 consumed, then the organism only carries out aerobic respiration; If an organism does not consume O2 but only produces CO2, then it only breathes anaerobically; If the organism releases more CO2 than absorbs O2, aerobic respiration and anaerobic respiration are carried out simultaneously.
The physiological processes of ATP production include aerobic respiration, photoreaction and anaerobic respiration.
7, (b) the basic types of metabolism
1. Assimilation: Transforming nutrients ingested from the outside into their own components and storing energy.
① Autotrophic type: including photoautotrophic (such as green plants and algae) and chemoautotrophic (mainly referring to nitrifying bacteria).
② Heterotrophic (direct intake of organic matter) people, animals, parasitic and saprophytic bacteria and fungi.
2. Alienation: break down a part of its own components and release energy.
① Aerobic (aerobic breathing) people, most animals, plants, bacteria and fungi.
(2) anaerobic (anaerobic respiration) parasites, lactic acid bacteria and other anaerobic bacteria.
Facultative anaerobic bacteria: yeast, which carries out aerobic respiration under normal conditions and alcohol anaerobic respiration under anoxic conditions.
Chapter VI Life Course of Cells
1 (1) The concept and characteristics of cell cycle
Cell cycle: A constantly dividing cell, from the completion of one division to the completion of the next division.
Features: Long mitotic interval.
2. (3) Mitotic process of animals and plants and their comparison.
1. Process characteristics: interphase: chromosome replication (including DNA replication and protein synthesis).
Prophase: Chromosome appears, arrangement is disordered, spindle appears, nuclear membrane and nucleolus disappear (two missing and two appearing).
Metaphase: Centromeres of all chromosomes are arranged neatly on the equatorial plate (chromosome observation and counting).
The best time for statistics)
Late stage: centromere breaks, sister chromatids separate, and move to cell poles (chromosome number is temporary).
Double time)
At the end stage: chromosomes and spindles disappear, and nuclear membranes and nucleoli appear (two exist and two are missing).
Note: ① There are homologous chromosomes in all stages of mitosis, but there is no combination and separation of homologous chromosomes.
② The equatorial plate is a virtual "plate", but the cell plate is real.
2. Variation characteristics of chromosomes, chromatids and DNA: (assuming the somatic chromosome is 2N)
Chromosome changes: doubled in late stage (4N) and unchanged in normal stage (2N).
DNA changes: the interval doubled (2N→4N) and the terminal decreased (2N).
Chromatid changes: It appears at interphase (0→4N) and disappears at later stage (4N→0), and the number of chromatids is the same as that of DNA.
Note: ① Chromosome number = centromere number.
② When the chromosome contains no sister chromatids, a chromosome contains only one DNA molecule; When a chromosome contains sister chromatids, a chromosome contains two DNA molecules.
3, the difference between animal and plant mitosis
Prophase: Plants form spindles from spindle filaments, while animals emit stars from centrosomes.
Thread forming spindle
Late stage: (Cytoplasmic division is different) Cell plate appears in the middle of the plant; Animals sag and crack from the outside to the inside.
3 (a) Three ways of eukaryotic cell division
1, mitosis: the division of most biological cells and fertilized eggs.
Essence: The chromosomes of the mother cell are copied and evenly distributed to the two daughter cells.
Significance: To maintain the stability of genetic traits between parents and children.
2. Meiosis: special mitosis of generative germ cells.
Essence: Once the chromosome is copied, the cell divides twice continuously, and the chromosome number of the new cell is halved.
3, amitosis: no chromosomes and spindles. For example, the red blood cell division of frogs.
4. (2) The concept and significance of cell differentiation
Cell differentiation: the process in which the offspring of the same cell have different morphology, structure and physiological function stability during individual development.
Cell differentiation stage: occurs in the whole life process of an organism and reaches its maximum in the embryonic stage.
Characteristics of cell differentiation: stability, persistence and irreversibility.
The cause of cell differentiation: the result of gene selective expression under specific time and space conditions.
Comparison of cell differentiation degree: somatic cell >; Germ cell > fertilized egg
Cell totipotency: Highly differentiated plant cells still have the ability to develop into complete plants. In all kinds of biological cells, fertilized eggs have the highest totipotency.
5. (1) Characteristics and carcinogenic factors of cancer cells
1, cancer cell characteristics: infinite proliferation, morphological structure changes, cancer cell surface changes (so it is easy to spread and metastasize).
2. Carcinogenic factors: physical carcinogens (radiation), chemical carcinogens and viral carcinogens.
Internal cause of canceration: mutation of proto-oncogene and tumor suppressor gene.
6, (a) the main characteristics of aging cells
Intracellular moisture decreased; The enzyme activity decreased; Pigment accumulation; Breathing slows down and nuclear volume increases; Changes in membrane permeability.
7, this chapter (a) experiment:
Mitotic mounting: dissociation (15% hydrochloric acid and 95% alcohol) → rinsing → dyeing (basic gentian violet) → production.
Two review points for compulsory exams
Chapter 1 Discovery of Genetic Factors
1.(a) Mendel used "hypothesis deduction" in his genetic experiment, so what is the reason for his success?
Correct selection of experimental materials; Research methods from single factor to multi-factor; The experimental results are analyzed by statistical method. The design of experimental scheme is scientific.
2. (2) Basic concepts
1. Relative traits: Different manifestations of the same trait of an organism, such as smoothness and shrinkage of seeds.
Dominant traits: Mendel called the traits that appeared in the first generation of hybrid seeds dominant traits;
Recessive traits: the traits that are not revealed in the first generation of hybrid seeds are called recessive traits.
2. Alleles: Genes that control relative traits are called alleles. Such as d and D. 1: 1
Non-allelic genes: different genes that exist in different positions of non-homologous chromosomes or homologous chromosomes and control different traits.
3. Heterozygote: individuals with different genetic factors, such as Dd and AaBB. (unable to inherit stably, and the offspring are separated)
Homozygote: individuals with the same genetic composition, such as AA and AAbb. (stable inheritance, no character separation)
4. Character separation: The phenomenon that both dominant and recessive characters appear in hybrid offspring is called character separation.
5. Phenotype: the characteristics of individual organisms (such as long-stemmed peas).
Genotype: the composition of genes related to phenotype. (e.g. dd, Dd)
The phenotype is the same, but the genotype is not necessarily the same. Genotype is the same, if the environment is the same, the phenotype is the same; If the environment is different, the phenotype is not necessarily the same.
6. Test crossing: F 1 hybridizes with recessive homozygote. The segregation ratio of offspring traits is 1: 1.
It can be used to detect whether dominant traits are homozygous or heterozygous.
Cross: refers to the cross between individuals of different genotypes, which is manifested by pollination of different plants and mating between different individuals of animals.
Self-pollination refers to the hybridization between individuals with the same genotype, plants pollinate themselves, and animals are between individuals with the same genotype.
Mate with ...
3.(a) Six basic mating combinations (taking tall stem D and short stem D of pea as examples)
①DD×DD→DD tall stem ②Dd×Dd→DD:2Dd:dd =3 height: 1 short; ③dd×dd→dd short stem.
④Dd×dd→Dd:dd= 1 height: 1 height: 5 DD× DD → tall stem: 6 DD× DD → DD: DD tall stem.
The hybrid offspring of homozygotes are not necessarily homozygotes, and the hybrid offspring of heterozygotes are not necessarily heterozygotes.