Thread theory
1. Biological science is a science that studies life phenomena and the laws of life activities.
Second, the basic characteristics of biology
(1) has the same material basis and structural basis.
* * * Same substance composition: protein and nucleic acid.
Structural basis: cell structure (except virus)
(2) Both of them have metabolism.
There is an exchange of matter and energy between organisms and the external environment.
The basis of all life activities, the most essential feature that distinguishes living things from nonliving things.
(3) Both are irritable.
Roots of Plants: Geotropism, hydrotropism and Fertility.
Stems of plants: phototropism, shadow
Animals: Avoid harmful stimuli and tend to favor them.
(4) all have growth, development and reproduction.
Reasons for growth: Assimilation is greater than alienation.
Growth performance: the increase of cell number and cell volume.
Starting point of individual development: fertilized egg
The purpose of reproduction: to continue the race
(5) Both have the characteristics of heredity and variation.
Heredity: "Dragon begets dragon, phoenix begets phoenix, and the son of a mouse can dig a hole" and "As you sow, you reap melon"-maintaining racial stability.
Variation: "One pig gives birth to nine babies, even ten mothers"-beneficial to biological evolution.
(six) can adapt to and influence a certain environment (such as lichen).
Third, the development of biological science.
(1) Descriptive biological stage:
1.65438+In 1930s, German botanist Schleiden and zoologist Wang Shi put forward the cell theory.
2. 1859, British biologist Darwin published the Origin of Species.
(2) experimental biology stage:
1900, Mendel's law of heredity was put forward again, marking the beginning of the stage of experimental biology.
(3) molecular biology stage:
1. 1944, American biologist Avery first proved that DNA is genetic material.
2. 1953, Watson of the United States and Crick of the United Kingdom proposed the DNA double helix structure model. (marks the beginning of the stage of molecular biology)
Fourth, the development direction of contemporary biology.
Microscopic direction: from cytological level to molecular level.
Macro direction: the development of ecology solves the global environmental and resource problems.
Chapter 1 Material Basis of Life-Chemical Elements and Compounds that Constitute Organisms
1. Chemical elements that make up organisms can be found in inorganic nature, and none of them are unique to the biological world. This fact shows that the biological world and the non-biological world are unified.
2. The fact that the content of chemical elements that make up an organism is quite different between organic and inorganic nature shows that there are still differences between the biological world and the abiotic world.
3. The basic elements that make up an organism are C, H, O and N, and the most basic element is C.
4. Macroelements: carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur, potassium, calcium and magnesium.
5. Trace elements: iron, manganese, copper, zinc, molybdenum and boron. Iron is a semi-trace element.
6. The main elements that make up an organism (rabbit) are C, H, O, N, P and S, and the most abundant element is O.
7. Plants are "flowery but not solid" because of boron deficiency.
8. The most abundant compound in various organisms is water, which exists in free water and combined water.
9. People will have convulsions due to calcium deficiency, indicating that inorganic salt ions can maintain the life activities of organisms.
10. Sugar is the main energy substance for organisms to carry out life activities, and glucose is an important energy substance for life activities.
1 1. The substance that stores energy in plant cells is starch, the substance that stores energy in animal cells is glycogen, and the main substance that stores energy in organisms is fat.
12. Lipids include fats, lipids (phospholipids form cell membranes) and sterols (cholesterol, sex hormones and vitamin D).
13. protein is the embodiment of life activities, and its structural unit is amino acid. The general structural formula is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
Amino acids undergo dehydration and condensation to form peptide bonds, which are connected to form polypeptides.
14. The diversity of protein depends on the type, quantity, arrangement order of amino acids and the spatial structure of protein.
15. nucleic acid is the genetic material of all living things and the decisive factor of life activities, and its structural unit is nucleotide. There are two types of nucleic acids: DNA and RNA. DNA exists in nuclei, mitochondria and chloroplasts.
Chapter II Cell, the Basic Unit of Life
16. Cell membrane is based on phospholipid bilayer, and its structural feature is that it has certain fluidity. The function of cell membrane is material exchange and protection, and its functional feature is selective permeation. Active transportation requires carrier and ATP.
17. The chemical components of cell wall are cellulose and pectin, which support and protect plant cells.
18. Cytoplasmic matrix is the main site for metabolism of living cells, which provides necessary substances (enzymes, ATP, etc. ) and certain environmental conditions for metabolism.
19. Mitochondria are the main places for aerobic respiration of living cells. Chloroplast is the place where green plants carry out photosynthesis.
20. The endoplasmic reticulum is related to the synthesis of protein, lipids and sugars, and it is also the transport channel of protein, which increases the membrane area in cells.
2 1. Ribosome is the place where protein is synthesized in cells. Prokaryotic cells only have ribosomes as organelles.
22. Golgi apparatus in cells is related to the formation of cell secretions, and is mainly used for processing and transporting protein; Golgi apparatus is related to the formation of cell wall during plant cell division.
23. Centrosomes are unique organelles of animals and lower plant cells. During mitosis, starlight is emitted to form a spindle.
24. Chromatin and chromosome are two forms of the same substance in cells at different times.
25. The nucleus is the place where genetic materials are stored and copied, and it is the control center of cell genetic characteristics and cell metabolic activities.
26. Only when cells maintain their integrity can they normally complete various life activities.
27. Cells proliferate in the form of division, and cell proliferation is the basis for the growth, development, reproduction and inheritance of organisms.
28. The significance (characteristic) of cell mitosis is that the chromosomes of the mother cell are accurately and evenly distributed to the two daughter cells after replication, thus maintaining the stability of genetic traits between biological parents and offspring, which is of great significance to the inheritance of organisms.
29. Cell differentiation is a permanent change, which occurs in the whole life of an organism, but reaches its maximum in the embryonic period.
30. Highly differentiated plant cells still have the potential to develop into complete plants, that is, to maintain cell totipotency.
Chapter III Biological Metabolism
3 1. Metabolism is the most basic feature of living things, and it is also the most essential difference between living things and nonliving things.
32. Enzyme is a biocatalytic organic substance produced by living cells, most of which are protein and a few are RNA.
33. Enzyme catalysis has high efficiency and specificity; It needs proper temperature and pH value.
34.ATP (adenosine triphosphate) is the direct source of energy needed for metabolism. Simple structure: a-p ~ p ~ p
35. Photosynthesis refers to the process that green plants use light energy through chloroplasts to convert carbon dioxide and water into energy-storing organic matter and release oxygen. All oxygen released by photosynthesis comes from water.
36. Infiltration must meet two conditions: one is to have a semi-permeable membrane, and the other is to have a concentration difference between the solutions on both sides of the semi-permeable membrane. When mature plant cells are in 30% sucrose solution, mature plant cells will undergo osmotic dehydration, showing the phenomenon of plasma-wall separation. The driving force for absorbing and transporting water is transpiration. More than 95% of the water absorbed by plants is lost through transpiration, and a small amount is used for life activities.
37. The absorption of mineral elements by epidermal cells in the mature area of plant roots and osmotic water absorption are two relatively independent processes. The way to absorb mineral elements is active transportation. Breathing provides power for the absorption of mineral elements, and transpiration is the power for transporting mineral elements.
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39.
For organisms, the physiological significance of breathing is manifested in two aspects: one is to provide energy for the life activities of organisms, and the other is to provide raw materials for the synthesis of other compounds (such as amino acids) in the body.
4 1. Respiration can be divided into aerobic respiration and anaerobic respiration. 1mol glucose releases 2870KJ of energy by aerobic respiration, and 1 16 1KJ of energy is stored in ATP.
Chapter IV Adjustment of Life Activities
42. The phototropism experiment found that the part that feels light stimulation is at the top of coleoptile, the part that produces auxin is at the top of coleoptile, and the part that bends towards light is at a section below the top.
43. The effects of auxin on plant growth are usually twofold. This is related to the concentration of auxin and the type of plant organs. Generally speaking, low concentration promotes growth and high concentration inhibits growth.
44. Seedless fruit can be obtained by coating a certain concentration of auxin solution on the pistil stigma of unpolluted tomatoes (cucumbers, peppers, etc.). ).
45. Auxin can promote fruit development, and ethylene can promote fruit ripening.
46. Hypothalamus is the center of the body to regulate endocrine activities. Growth hormone deficiency in childhood will show dwarfism; Childhood thyroid hormone deficiency can manifest as dementia. Adults with too much thyroid hormone will develop hyperthyroidism.
47. Related hormones have synergistic effects (such as growth hormone and thyroid hormone) and antagonistic effects (insulin and glucagon).
48. The basic way for the nervous system to regulate various activities of animals is reflex. The structural basis of reflex activity is reflex arc (consisting of five parts: receptor, afferent nerve, nerve center, efferent nerve and effector).
49. Neurons can generate and conduct excitement after being stimulated; The transmission of excitement on nerve fibers is bidirectional; Excitement is transmitted between neurons through synapses (composed of presynaptic membrane, postsynaptic membrane and synaptic gap), and the transmission of excitement between neurons can only be one-way.
50. In the central nervous system, the higher center that regulates the physiological activities of human beings and higher animals is the cerebral cortex. The motor center of the body is in the anterior central gyrus. Motor aphasia (inability to speak) will occur when S area is injured, and auditory aphasia (inability to understand others) will occur when H area is injured.
5 1. Prolactin secreted by pituitary gland can not only regulate the care behavior of animals for their young, but also promote the development of some synthetic food organs and the completion of physiological functions, such as promoting the development and lactation of mammalian mammary glands and the secretion of pigeon milk from pigeon crop.
52. In the acquired behavior of animals, life experience and learning play a decisive role in the formation of behavior. The main way for animals to establish acquired behavior is conditioned reflex. Animal imprinting learning only happens when it is just hatched.
53. Judgment and reasoning are the most advanced forms of animal acquired behavior development. In animal behavior, humoral regulation and neuromodulation are coordinated, but neuromodulation is still dominant.
Chapter V Reproduction and Development of Organisms
54. There are fission propagation (amoeba, paramecium and bacteria), budding propagation (yeast, hydra), spore propagation (Penicillium, Adiantum), vegetative propagation (potato tuber, strawberry stolon), tissue culture and cloning.
55. The offspring produced by sexual reproduction have the genetic characteristics of their parents and have greater vitality and variability, so they are of great significance to the survival and evolution of organisms.
56. Asexual reproduction enables offspring to retain all the characteristics of their parents.
Because of meiosis, the number of chromosomes in sperm and egg cells is half that of somatic cells. Chromosomes in daughter cells obtained by mitosis are equal to those in somatic cells.
58. In the late stage of the first meiosis, homologous chromosomes are separated and non-homologous chromosomes are freely combined.
59. During meiosis, the number of chromosomes is halved in the first meiosis.
60. A spermatogonia undergoes meiosis to form four sperm cells, which undergo complex changes to form sperm.
6 1. Oocytes undergo meiosis to form only one egg cell.
62. For sexually reproducing organisms, meiosis and fertilization are very important for maintaining the number of chromosomes in somatic cells of each offspring, as well as for the inheritance and variation of organisms.
63. For sexually reproducing organisms, the starting point of individual development is the fertilized egg and the end point is the sexually mature individual. In the process of angiosperm seed formation, the ovary develops into fruit, the ovule develops into seed, the fertilized egg develops into embryo, and the fertilized polar nucleus develops into endosperm.
64. Many dicotyledonous plants (soybean, peanut, shepherd's purse) have no endosperm in their mature seeds, because endosperm is absorbed by embryos during the development of embryos and endosperm, and nutrients are stored in cotyledons for later seeds to germinate. Most monocotyledonous plants (corn) have endosperm in their mature seeds.
65. The formation of plant flower buds marks the beginning of reproductive growth.
66. The individual development of higher animals can be divided into two stages: embryonic development and post-embryonic development. Embryo development refers to the development of fertilized eggs into larvae. Post-embryonic development means that larvae hatch from egg membrane or develop into sexually mature individuals from maternal endogenous sources (frog's post-embryonic development is metamorphosis). The individual development of angiosperms can be divided into two stages: seed formation and germination, and plant growth and development.
67. The gastrula has three layers of germ layers: ectoderm, mesoderm and endoderm. The amniotic membrane and amniotic fluid of animals (reptiles, birds and mammals) not only ensure the water environment for embryo development, but also have the function of earthquake protection.
Chapter VI Inheritance and Variation
68. The DNA of S-type bacteria can make R-type bacteria produce S-type bacteria, and various characteristics of phage are also passed on to future generations through DNA. These two experiments prove that DNA is genetic material.
69. Modern scientific research has proved that genetic material contains RNA in addition to DNA. Because the genetic material of most organisms is DNA, DNA is the main genetic material. The genetic material of tobacco mosaic virus and SARS virus is RNA.
70. 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. This explains why organisms have diversity and specificity at the molecular level.
7 1. The transmission of genetic information is accomplished by the replication of DNA molecules. The replication of DNA is a process of melting and replication.
72. The regular double helix structure of DNA molecules provides an accurate template for replication. Through base complementary pairing, replication can be accurately guaranteed. The way of DNA replication is called semi-conservative replication.
73. Descendants are similar to their parents in traits, because they have obtained copies of DNA copied by their parents.
74. Genes are DNA fragments with genetic effects. Genes are arranged in a straight line on chromosomes, which are the carriers of genes.
75. All genetic traits of organisms are controlled by genes. Gene expression is achieved by DNA controlling the synthesis of protein. The process of gene controlling protein synthesis includes two stages: transcription (in the nucleus) and translation (in the cytoplasm).
76. Because different genes have different deoxynucleotide sequences (base sequences), different genes contain different genetic information. (that is, the deoxynucleotide sequence of a gene represents genetic information).
77. The sequence of deoxynucleotides in DNA molecules determines the sequence of ribonucleotides in messenger RNA, and then determines the sequence of amino acids, and finally determines the specificity of protein's structure and function, thus making organisms show various genetic characteristics.
78. The phenomenon of gene segregation: When two organisms with a pair of relative characters are hybridized, the first generation only shows dominant characters; In the second generation, the phenomenon of character separation appeared, and the quantitative ratio of dominant characters to recessive characters was close to 3: 1.
79. The essence of the phenomenon of gene segregation is that when an organism forms a gamete through meiosis, the alleles will separate with the separation, enter two gametes respectively, and be passed on to the offspring independently with the gametes.
80. Genotype is the internal determinant of phenotype, and phenotype is the external expression of genotype. Phenotype = genotype+environment.
The essence of the law of free combination of 8 1. genes is that in the process of meiosis to form gametes, alleles on homologous chromosomes are separated from each other, and non-alleles on non-homologous chromosomes are freely combined.
82. There are two main methods to determine biological sex: one is XY type and the other is ZW type. Red-green color blindness and hemophilia are X recessive genetic diseases.
83. Genetic variation comes from three sources: gene mutation, gene recombination and chromosome variation. The only source of bacterial genetic variation is gene mutation.
84. Gene mutation is of great significance in biological evolution. It is the fundamental source of biological variation and provides raw materials for biological evolution. Whether gene mutation is harmful or beneficial depends on its environment.
85. Genetic recombination through sexual reproduction provides an extremely rich source of biological variation. This is one of the important reasons for the formation of biodiversity and is of great significance to biological evolution.
86. The function of colchicine is to inhibit spindle formation and double the number of chromosomes. The plants obtained from anther culture in vitro are all haploid plants. Haploid plants treated with colchicine must be homozygous. The advantage of haploid breeding is that the breeding cycle is obviously shortened.
The measures to promote eugenics include: forbidding consanguineous marriage (the simplest and most effective method), conducting genetic counseling, advocating "childbearing of appropriate age" (female aged 24-29) and prenatal diagnosis.
Chapter VII Evolution of Organisms
88. The process of biological evolution is essentially a process of changing the gene frequency of a population. The basic content of modern biological evolution theory: population is the unit of biological evolution; Mutation and gene recombination are raw materials for evolution; Natural selection determines the direction of biological evolution; Isolation leads to speciation. (If AA=30, Aa=60 and aa= 10, the gene frequency of A is (60+10 * 2)/100 * 2 = 40%).
89. The core of modern biological evolution theory is the theory of natural selection. Its basic view is that population is the basic unit of biological evolution, and the essence of biological evolution lies in the change of population gene frequency. Mutation and 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.
Chapter VIII Biology and Environment
90. In a certain area, the distribution of total precipitation and rainy season in a year are important factors to determine the distribution of terrestrial organisms. Food supply in winter is the key factor affecting deer survival.
9 1. Ecological factors can be divided into abiotic factors and biological factors (intraspecific relationship and interspecific relationship). Intraspecific relationship includes intraspecific struggle and intraspecific mutual assistance; Interspecific relationships include mutualism, parasitism, competition and predation.
92. In a certain area, individuals of the same species form a population. All populations in the same area form a community. Population has four characteristics: population density, birth rate and death rate (which determine population density and population size), age composition (growth, stability and decline, which can be used to predict population trends) and sex ratio (which affects population density to some extent).
93. Population growth curve: S-shaped growth curve and J-shaped growth curve. Under the ideal conditions of sufficient food, sufficient space, suitable climate and no heaven and earth, the population growth is J-shaped; Under natural conditions, environmental conditions are limited. With the increase of population, intraspecific struggle, interspecific competition and predators increase, which makes the population growth rate decrease. When the population reaches the maximum value (k value) allowed by environmental conditions, the population stops growing. In this process, the growth first increases and then decreases, so the growth curve is S-shaped.
94. The largest ecosystem on earth is the biosphere. There are many kinds of animals and plants in forest ecosystem, and the community structure is complex, and the population density and community structure are in a stable state for a long time. Most animals in grassland ecosystem have the characteristics of digging holes or running fast. The main feature of farmland ecosystem is that people play a key role, and crops planted by people are the main members of farmland ecosystem. Abiotic factors affecting marine life are mainly sunlight, temperature and salinity of seawater.
95. Composition of ecosystem: abiotic substances and energy, producers (main components), consumers and decomposers. Food chain and food web are the nutritional structure of ecosystem. The organisms in the third trophic level in the food chain must be secondary consumers. The total amount of solar energy fixed by producers is the total energy flowing through this ecosystem. These energies flow step by step along the food chain (net).
96. The energy flow in the ecosystem is characterized by one-way flow and decreasing. Characteristics of material circulation: it can be reused.
97. The more species of organisms at different trophic levels in the ecosystem, the more complex the trophic structure, the stronger the self-regulation ability and the greater the stability of resistance. For an ecosystem, the relationship between resistance stability and resilience stability is often the opposite.
98. Biodiversity (genetic diversity, species diversity and ecosystem diversity) is the basis of human survival and development. The main reason that biodiversity in China is threatened is the change and destruction of living environment. For rare and endangered species, it is necessary to strictly protect them and prohibit all forms of hunting, mining and trading.
99. Excessive SO2 in the atmosphere is the main cause of acid rain. Sources of SO2 in the atmosphere: combustion of fossil fuels, volcanic eruption and decomposition of microorganisms. Acid rain is called "death in the air".
100. The stable state of biosphere is the foundation of sustainable development of human society and economy. In production and life, human beings should establish a waste-free production system, that is, change the traditional "raw material-product-waste" production mode into "raw material-product-raw material-product".