Hebei province municipal trial examination questions
Instructions for answering questions;
1 This test paper is ***8, with a total score of 120 and an examination time of 120 minutes.
Please draw the correct answer on the machine-readable card with 2B pencil.
1. Multiple choice questions (there is only one correct answer to each small question, 1 point, 80 points for each question * * *)
1. Hundreds of people all over the world die every year because of eating poisonous mushrooms by mistake. Amanita is a toxin of poisonous mushrooms, and it is a cyclic octapeptide. If the average molecular weight of 20 amino acids is 128, the molecular weight of Amanita is about
1024
2. Which of the following phenomena belongs to specific immunity?
A. Lysozyme in tears can kill Chlamydia trachomatis B, and phagocytes in lymph nodes devour streptococcus invading human body.
C hydrochloric acid in gastric juice can kill some bacteria that enter the stomach. Smallpox antibodies in the body can protect against smallpox virus.
3. The following figure shows the biochemical reaction of Thiobacillus ferrooxidans in vivo, from which it can be judged that its metabolic type is
A. autotrophic anaerobic D. heterotrophic anaerobic C. white aerobic D. heterotrophic aerobic D.
4. In China, rubber trees can only be distributed in 24 ~ 40 north latitude, south and below 960m above sea level. The main ecological factors affecting rubber distribution are
A. sunlight B. moisture CO2 concentration D. temperature
5. The picture on the right shows the chromosome composition of two sperm cells taken from animal testis. If chromosome ear exchange is not considered, the speculation about the origin of these two sperm cells is wrong.
A it may come from spermatogonia or primary spermatocytes.
C. it may come from two primary spermatocytes. It may come from a secondary spermatocyte.
6. The green of pea pods is dominant to the yellow. After the pistil of hybrid green pea receives the pollen of yellow pea, the color of dozens of pods should be
A. They are all green. B. The ratio of green to yellow is close to 3: 1.
C. it's all yellow. D. the ratio of green to yellow is close to1:L.
7. A woman who used drugs for a long time gave birth to a brainless child. The most likely reason for this phenomenon is during embryonic development.
A. The development of blastocyst into gastrula is inhibited. B. The cleavage process is inhibited.
C. The formation of mesoderm is inhibited, and the development of N part of ectodermal cells is inhibited.
8. The latest genetic research shows that about 80% of the genes of human and mouse are the same, so the proportion of the same DNA base sequence of human and mouse is
A.40% B.80% C.20% D. Not sure.
9. The frequency of color blindness gene is 7%. A normal man marries a normal woman who is not related by blood. What is the possibility of his offspring suffering from color blindness?
b . 7/ 100 c . 3.5/400d . 13/400
10. At the junction of two ecosystems (grassland and forest), there is a transitional zone. Compared with two adjacent ecosystems, the biological characteristics of the transitional zone are as follows
A. there are many kinds of creatures. B. There are few kinds of creatures. C. there are few kinds of plants. D. there are many parasitic animals
1 1. The following statements about the genome are correct.
A there are no non-homologous chromosomes in genome d, and the genome only exists in somatic cells.
C. Sexual germ cells contain only one genome. D. there are no alleles in the genome.
12. Animals with ladder nervous system are
A. Protocorm B. Eucorm C. Two germ layers D. Three germ layers
13. Long-day plants are introduced from south to north, and their growth period changes and introduction requirements are as follows
A. shorten the growth period and introduce early-maturing variety B.
C. Prolonging the growth period and introducing early-maturing varieties.
14. Long-term malnutrition and decreased plasma protein will cause tissue edema. this is because
A. the rate of plasma infiltration into tissue fluid decreases. B. the lymphogenesis rate is reduced.
C. the permeability of tissue fluid decreases. D. Obstruction of lymphatic circulation
15. The callus cells were cultured for several hours in a medium containing all necessary substances (the medium contains cytosine labeled with tritium). If autoradiography is used to detect these callus cells, no radioactive substances will be found.
A. Mitochondrial ribosome nuclear vacuole
16. By analyzing the double-stranded DNA molecules of organisms, it is found that the sum of guanine and cytosine accounts for a% of all bases (A >; 0), in which guanine on one strand accounts for b% (b, 0) of all bases on the chain, and guanine on the complementary strand accounts for the whole DNA molecular base.
A.a/2%—b/2% B，a %—B % c .(a %—B %)/( 1—a %)d . B %—a/2%
17. The genotype of pea is Aa. Let it pollinate itself for three generations in a row. How often does a gene appear in its offspring?
12.5% 25% 50% d . 75%
18. The following statement about the origin of effector B cells is correct.
A. Most effector B cells come from B cells directly stimulated by antigens.
B. Memory cells can produce effector B cells after antigen treatment.
C. effector b cells are all produced after t cells present antigens.
D.b cells develop into effector b cells in thymus.
19. When fertilizing saline-alkali land, you should choose
A.(NH4)2s 04 B . nano 3 C . kno 3D . nh4no 3
20. In photosynthesis, the central molecule of photochemical reaction is
A. all chlorophyll a molecules in various states B.P700 and P680 chlorophyll molecules.
C. all chlorophyll molecules and carotenoid molecules D. enzyme molecules related to photosynthesis
2 1. It is known that the genotype of the individual is AaBb, and the following inference is correct.
A. If an individual has only one parent, its genotype must also be AaBb.
B. If an individual has two parent trees, their genotypes must be aabb and AABB respectively.
There must be four types and proportions of gametes produced by this individual, each accounting for 25%.
D. there must be aabb genotype individuals in the offspring produced by selfing.
22. Vasectomy is one of the methods of male birth control. If a fertile young man has a broken vas deferens due to trauma, and the vas deferens is reopened after the trauma is cured, it is found that there are normal amounts of sperm in his semen after the operation, but it is not alive. The most likely reason is that
A. the injury has affected the testis. D. Epididymis, prostate and other organs are damaged or not healed.
C. the corresponding antibody is produced in vivo. D. the communication operation was unsuccessful.
23. Thin people have the least lipid content.
A. phospholipid D. cholesterol C. sex hormone D. fat
24. The substance that can directly destroy the function of biofilm is
A. distilled water B. protease C. lipase D. carbon dioxide
25. The mammalian thermoregulatory center is located in which of the following structures?
A. cerebral cortex B. cerebellum C. hypothalamus D. medulla oblongata
26. If the ocean is slightly polluted by organic matter, the sequence of continuous changes is as follows
(1) oxygen content in water is reduced; ② Bacteria that decompose organic matter multiply rapidly; ③ The oxygen content in water increases,
④ Rapid propagation of phytoplankton ⑤ Increase of inorganic salt ions such as NH4+.
A.②①④⑤③ B.②①⑤③④ C.④③②⑤① D.②①⑤④③
27. The following statement about genes is incorrect.
A. As long as the conditions are met, it can be accurately replicated in vivo and in vitro.
The expression of the same gene in different cells is different.
There will be no similarity in the sequence of four base pairs between any different genes.
D. All genes have certain genetic effects.
28. Among the following biological characteristics that control the transfer of genetic material, those that do not follow Mendel's genetic law are
A. Human color blindness B. Inheritance of color of Lilium brownii plants
C. Inheritance of seed coat shape and cotyledon color of pea D. Inheritance of streptozotocin mitochondria
29. The following statements about cell structure and function are incorrect.
A. The active absorption of 5i by rice needs the assistance of the carrier on the root cell membrane.
B. The ability of thyroid cells to accept the regulation of thyroid stimulating hormone is related to the glycoprotein on their cell membranes.
C ribosome is the "assembly machine" of intracellular protein, which is composed of protein and mRNA.
D. Nuclear pore is a channel for substance exchange between nucleus and cytoplasm.
30. Besides mesophyll cells, which of the following C4 plants also contains chloroplasts?
A. vascular bundle sheath cells B. phloem cells in vascular bundle
C. leaf epidermal cells
3 1. The following figure is a pedigree diagram of a family genetic disease. The following statement is incorrect.
A. From the performance of 5×6→8 and 9, the disease is a dominant genetic disease, and 5 and 6 are heterozygotes.
B. Because 2, 4 and 8 people are all patients, the disease must be a sex-linked genetic disease.
The genotype of C.8 is not necessarily homozygous.
D.4 and 5 are collateral blood relatives, 1, 5 and 8 are direct blood relatives.
32. In prokaryotes, 1 base pair is inserted at the beginning of gene coding region. Near the insertion site, which of the following may have the least influence on the encoded protein structure?
A. replacing a single base pair B. adding four base pairs
C. deletion of 3 base pairs D. deletion of 4 base pairs
33. The following can be used to identify whether weeds are C: The simplest method for plants is
A, making temporary slices of leaf epidermis and observing the size of stomata; B, making a temporary blade cross section and observing the vein structure.
C, separating and measuring the content d of various pigments in leaves. Determination of starch content in leaves with iodine solution
34. Prepare tomato leaf cells and potato root tip cells into protoplasts, then mix them, and add dissolution promoter. Which of the following microscopes is most suitable for observing whether these two kinds of cells can fuse?
A. General optical microscope B. Fluorescence microscope C. Phase contrast microscope D. Electron microscope
35. If …CGUUUUCUUACGCCU… is a fragment of mRNA produced by a certain gene, if a base is added at a certain position in the sequence, expression may occur.
① The amino acid sequence of peptide chain towel was completely changed ② The peptide chain was interrupted in advance.
③ Prolonged peptide chain ④ No change ⑤ Cannot express peptide chain.
A.①②③④⑤ B.①②③④ C.①③⑤ D.②④⑤
36. Cell differentiation is a common life phenomenon in biology. The following is incorrect.
A. differentiation occurs in the whole life process of an organism.
B. the genetic material has changed in the process of differentiation.
C. Unseparated somatic cells will not show totipotency.
D differentiation is the result of selective expression of genes under specific time and space conditions.
37. The following technologies (methods) selected for biological research are inappropriate.
A feeding yeast cells with 3H-labeled cytosine ribonucleic acid to study DNA replication.
B, obtaining cell mitochondria by differential centrifugation, and studying its aerobic respiration function.
C.DNA fingerprinting technology to identify paternity.
D. Test the toxicity of a substance by animal cell culture.
38. All nitrogen-fixing organisms found at present do not have which of the following structures?
A. cell wall B. DNA and RNA C chloroplast n ribosome
39. The following statement about excitation conduction is correct.
A. The direction of local current flow in nerve fiber membrane is consistent with the direction of excitation conduction.
B. The excited part of nerve fiber will return to zero potential at rest.
C. Synaptosome completed the transformation of "chemical signal ~ ~ ~ electrical signal"
D. Neurotransmitters act on the postsynaptic membrane to excite it.
40. Under aseptic conditions, a proper amount of yeast was put into a sealed container with appropriate concentration of glucose solution, and after a period of constant temperature culture at 40℃, it was found that the air pressure in the container increased. The reason for the increase in air pressure is
A. yeast has aerobic respiration.
C. Yeast D germinated and propagated to produce a large number of cells, and a large number of yeast died and decomposed to produce a large number of carbon dioxide.
4 1. A foreign gene successfully transformed into a recipient cell by genetic engineering does not necessarily need which of the following to be stably expressed?
A. coding B. promoter C. intron D. terminator
42. The following organisms belong to single-celled organisms are
A. algae b, pneumococcus c, mold d, hepatitis virus
43. The following statement about cell membrane is correct.
A. The thickness is less than 1 nm, and a layer of protein is sandwiched between two layers of phospholipid molecules to form a sandwich structure.
B. It is about 8nm thick and consists of two layers of phospholipid molecules, each of which contains protein.
C is a semi-permeable membrane, so small molecules can pass through.
D. stable and firm, providing an effective barrier for cells.
44. The supercilious gene of Drosophila melanogaster is controlled by recessive gene on X chromosome. Hybrid female fruit flies mate with normal male fruit flies. White eyes will appear in
A. All offspring B. All male offspring, but no female offspring.
C. there are no female offspring, and 50% male offspring have D.
45. Which of the following statements about gene mutation is wrong?
Generally speaking, only mutations that occur in germ cells can be passed on to the next generation through gametes.
D. Gene mutation is not only reversible, but also most mutations are harmful.
C gene mutation occurs in the process of DNA replication between cell divisions.
D. because gene mutation has no directionality, gene a can be mutated into gene B.
46. Among the following four biological towels, which one is obviously different from the other three in cell structure?
A. lactic acid bacteria b yeast c strawberry d mushroom
47. If a gene is transcribed into RNA, the percentage of A+U is 30%. Then the percentage of G+C in this gene should be
A.70% B.30% C.50% D.60%
When some bacteria are treated with effective antibiotics, some individuals are still alive. The correct explanation for this phenomenon is
A. antibiotics make it resistant to mutation.
B. individuals with drug resistance genes in the population.
C. Antibiotics prevented the variation of drug resistance.
D. Antibiotics kill other bacteria and reduce competition with other bacteria, thus improving the chances of survival.
49. The following statements about nitrogen and phosphorus are correct.
A. Rhizobia and chromosphere nitrogen-fixing bacteria can transform nitrogen into N03.
B. When normal plants are transferred to a medium containing no N and P, the top leaves of the plants first appear element deficiency.
Carbon, nitrogen and phosphorus are one of the indispensable components of biofilm system.
D. Healthy teenagers are in the stage of growth and development. The amount of nitrogen and phosphorus absorbed is equal to the amount of nitrogen and phosphorus discharged.
50. The following statement about gene replication and expression is correct.
A. A codon can encode multiple amino acids.
Introns of genes can be translated into polypeptides.
Adding a base pair to the coding region will only change one amino acid in the peptide chain.
D. (C+T)/(A+C): 1 in the progeny DNA molecule after DNA molecule replication.
5 1. If the deer's food intake is 100%, the amount of feces and urine is 36%, and the respiratory capacity is 48%, then the deer's assimilation amount is
A.64% B.84% C. 16% D.52%
52. In natural biological communities, it is correct to say that a certain biological trophic level is
A. A species can only occupy one trophic level B? A species may occupy multiple trophic levels.
C. Carnivores are always in the second trophic level D, and the biomass of each trophic level remains unchanged.
53. In each forest type, the order of soil organic matter content from high to low is
A tropical rain forest, temperate broad-leaved forest and boreal coniferous forest B. boreal coniferous forest, temperate broad-leaved forest and tropical rain forest
C. temperate broad-leaved forest, boreal coniferous forest and tropical rain forest D. boreal coniferous forest, tropical rain forest and temperate broad-leaved forest
54. Which of the following substances needs to be transported through the intracellular membrane system?
A. Hemoglobin B. Myosin C. Respiratory enzyme D. Salivary amylase
55. Cells undergoing plasmolysis will gradually absorb water.
A. decrease B. increase C. constant D. equals 0
56. The following gene pedigree map is most likely to reflect hemophilia.
57. The following measures cannot remove the apical advantage of plants.
A. removing terminal buds
B. Put a piece of lanolin containing auxin on the broken door from which the terminal bud is removed.
C. Place a piece of lanolin containing cytokinin on the broken door with terminal bud removed.
D, putting agar small pieces on the fracture surface from which the terminal buds are removed.
58. Human congenital cataract is an autosomal dominant genetic disease, and hypocalcemia rickets is an X dominant genetic disease. A man with congenital cataract (normal hypocalcemia) married a woman with hypocalcemia rickets (normal eyeball) and gave birth to a normal girl. The couple gave birth to another boy and a girl twins.
The probability that both children are normal is
a . 1/ 16 b . 1/8 c . 1/32d . 1/64
59. The morphological structure and function of human nerve cells are different from those of liver cells. The fundamental reason is that these two kinds of cells are different.
A.DNA bases are arranged in different orders. Ribosomes are different.
C. different transport rnas. D. different messenger BNA
60. Plants with monomorphic stamens, dimorphic stamens and tetramorphic stamens are
A. Cruciferae, Malvaceae and Leguminosae
C. Leguminosae, Cruciferae and Malvaceae
6 1. What is the biggest relationship between the behavior of bees dancing figure-eight dance?
A. the distance of food source B. the direction of food source C. the richness of food D. the number of bees recruited
62. The color of ornamental plants is controlled by two pairs of alleles, which are located on two pairs of homologous chromosomes. A homozygous blue variety crosses a homozygous red variety, with P 1 being blue, P 1 selfing, and P2 being 9 blue: 6 purple: 1 red. If the purple plants in F: are pollinated with bright red plants, the phenotype and its ratio of offspring are
A.2 scarlet: 1 blue B.2 purple: 1 scarlet C. 1 scarlet: 1 purple D.3 purple: 1 blue.
63. The proportion of genes controlling O, A and B blood types in the population is 6: 3: 1. If married at random, the phenotypic proportions of blood groups A, B, O and AB are as follows.
A.0.45, 0. 13, 0.36 and 0.06b.0. 13, 0.45, 0.36 and 0.06.
C.0.06, 0.36, 0.45 and 0. 13d.0.45, 0.36, 0. 13 and 0.06.
64. Mendel's second law is manifested in
A. in the first division of meiosis
C. in the second division of meiosis.
65. Beans are plants pollinated by white flowers, and the color is dominant for white. A hybrid colorful kidney bean Cc lives on this island. If there are no other kidney bean plants on the island, and kidney beans are annual plants, then after three years, the ratio of colored kidney bean plants to colorless kidney bean plants on the island is
1 b . 15:7 c . 9:7d . 15:9
66. The metabolism of three nutrients is closely related to human health. The following statement is incorrect.
A high-fat and high-sugar diet may lead to fat accumulation in the liver, forming fatty liver.
B. Too much sugar and fat and protein in the human body may lead to obesity.
C. While rice is the staple food, the utilization rate of protein can be improved by matching beans.
Glycine is an essential amino acid. If the absorption is insufficient, the synthesis of protein will be hindered.
67. Which of the following is not a photoreceptor of plants?
A. cryptochrome1b. cytochrome e c. phytochrome a d. phytochrome b.
68. The organ that synthesizes urea is
A. kidney b liver c muscle d pancreas
69. In a cross involving three pairs of alleles in Drosophila melanogaster, a hybrid female Drosophila melanogaster with genotype (AaBbCe) crossed with a homozygous recessive male Drosophila melanogaster to obtain the following phenotype.
According to the result of this hybridization, we can draw a conclusion.
A.a and b genes are linked and freely combined with c gene.
B.a and c genes are linked and freely combined with b gene.
C. Genes A, B and C are not complete linkage, and the relative sequence of gene linkage is A-B-C.
The three genes D.A., B and C are not complete linkage, and the relative sequence of gene linkage is B-A-C.
70. Which of the following has nothing to do with the resolution of the microscope?
A. Wavelength of light wave B. Magnification of objective lens
C. refractive index of substance between sample and lens D. numerical aperture of lens
The function of 7 1. chromosome telomerase is
A. prevent DNA from degrading from telomeres; B' degrade RNA primers left after DNA replication.
C. prevent DNA from shortening due to replication process D. synthesize RNA primers.
72. What are the characteristics of the life history of fungi compared with the biological history of plants?
A. No sexual reproduction B. No diploid C. Rare meiosis D. Binuclear stage
73. The lysogenic virus is a kind of ().
A. nucleic acids can be integrated into chromosomes of host cells. B. it can be replicated immediately after entering cells.
C. contains ATP required for self-replication and contains enzymes required for self-replication.
74. The following do not belong to the physiological adaptation countermeasures of warm animals to low temperature environment.
A. Allen's law B. Reverse heat flow exchange mechanism C. Heat production D. Local inhomogeneity
75. In the life history of the following algae, the heterotypic generations dominated by sporophytes alternate as follows
A. Ulva yunnanensis, a polychaete.
76. Pasteurella is
A. Telomere B. Agglutinated X chromosome C. Satellite D. Giant chromosome
77. Before barley seeds germinate, embryos are removed and starch in the seeds cannot be hydrolyzed. If applied to it, which substance can most effectively make the seeds regain the ability to hydrolyze starch?
A. amylase b gibberellin c carbohydrate d deoxyribonuclease
78. A butterfly suddenly spread its wings, revealing bright black and red rings. What kind of behavior is this?
A. mimicry B. warning color C. intimidation D. escape
79. Which of the following statements about quadruped clavicle is correct?
A. The clavicle is a part of the forelimb bone, connecting the scapula and the sternum.
B. The clavicle is a part of the shoulder strap, which is directly connected with the thoracic vertebra.
The clavicle is a part of the forelimb bone, which connects the forelimb bone with the scapula.
D. The clavicle is a part of the shoulder strap and has no direct relationship with the spine.
80. Which of the following groups of glands or gland cells has no ducts?
A. Hartmann gland, prostate, infraorbital gland, thymus
B. Submandibular gland, parathyroid gland and urethral gland
C. lacrimal gland, thyroid gland, fish testis and fish ovary
D. Mammalian ovary, interstitial cell, islet, thyroid gland
Second, indefinite multiple-choice questions (each question has one or more correct answers, and multiple or fewer choices are not scored, and each question has 2 points, ***40 5- 1')
8 1. Which two diseases are similar in pathology?
A. Dementia B. AIDS C. Hemophilia D. Rheumatic heart disease
82. When a gene mutation occurs in an individual organism, which of the following changes will surely occur?
A. base sequence in A.DNA or RNA B. codon on B.mRNA
C. Types of amino acids in peptide chains D. Genetic information
83. The following narrative about genetic engineering is wrong.
A.DNA ligase connects base pairs at the sticky end.
D gene probe refers to DNA molecules labeled with radioisotopes or fluorescent molecules.
C gene therapy is mainly to repair Liu's defective cells
D the amino acid sequence in protein is called' providing information for the synthesis of the target gene'.
84. DNA molecules that can be used for genetic engineering are
A. bacterial pseudonuclear DNA B. viral DNA C. phage DNA D. plasmid DNA
85. According to the principle of energy pyramid drawing, which ecosystem towel producers and consumers in column F are likely to form an inverted pyramid?
A. city B. natural lake C. swamp D. artificial breeding pond
86. Teenagers are in a critical period of growth and development, and they need a certain amount of protein every day. The following description of protein's role in the human body is correct.
A is the basic substance that constitutes human cells. B is the main energy-supplying substance of human body.
C. It can provide energy for people's physiological activities D. protein is indispensable for people's growth, development and tissue renewal.
87. The following statement about biological control is correct.
A. the advantage of biological control is that it will not cause environmental pollution.
B. biological control is a technology that uses biology to control pests and diseases.
C biological control methods include pest control, bird control and bacterial control.
D. The combination of biological control and pesticide control will not affect biology and environment.
88. The main differences between chromosome structural variation and gene mutation are as follows.
A. Chromosome structural variation is the change of relatively large segments of chromosomes, while gene mutation is the change of single gene structure on DNA molecules.
B. Gene mutation can cause reversion mutation, but chromosome structural variation is difficult to cause reversion.
C gene mutation is generally a small mutation with small genetic effect, while chromosome structural variation is a big mutation with large genetic effect.
The structural variation of D chromosome can be identified by cytology, but gene mutation cannot be identified by cytology.
89. The absorption of mineral elements by plants is influenced by internal and external factors. The following statement is correct.
A. Respiratory inhibitors can reduce the absorption of mineral elements by plants.
B In a certain range, the absorption of mineral elements by plants increases with the increase of temperature.
There is no correlation between the absorption of water and mineral elements by roots.
D mineral elements must be in ionic state to be absorbed by roots.
90. In the following statement about photosynthesis, the fact is that
A. Photolysis of water occurs on thin films with layered structure.
B. There are many enzymes involved in both light reaction and dark reaction.
C when the temperature drops to 0℃, there are still plants that can carry out photosynthesis.
D.NADPH plays a reducing role in dark reactions and can transfer energy to sugar molecules.
9 1. Which of the following descriptions about DNA and mRNA is correct?
A.mRNA is easy to hydrolyze, while DNA is relatively stable.
B.DNA can be paired to form a double-stranded structure, while mRNA cannot.
C. Under certain conditions, both DNA and mRNA can form a double-stranded structure.
D. the mRNA of bacteria is as stable as its DNA.
92. When an ecosystem develops to a mature stage, which of the following characteristics are correct?
A. the total yield is greater than the community respiration. B. the net yield is high.
C. the food chain is dominated by clastic food chain d, with high species diversity.
93. Among the following foods, fruits are
A. Watermelon seeds B. Sunflower seeds and peanuts D. Corn kernels
94, in the carbon cycle, the physiological function of inorganic environment and biological community is
Photosynthesis B. respiration C. transpiration D. chemical synthesis
95. The following is the succession process.
A. emergent plants grow step by step in deep-water ponds. B. abandoning the DPRK: the growth of small plants in farmland.
C. The increase in the proportion of shrubs on grassland D. Changes caused by forest fires
96. The following statements about cell differentiation, senescence and death are correct.
A. Cell differentiation is a process in which cell offspring are different in morphology, function and genetic material.
B. Cell senescence will lead to the decrease of mitochondria, the decrease of enzyme activity and the increase of nuclear volume.
C. Cell differentiation occurs in the embryonic stage of multicellular organisms, and cell senescence and death occur in the old age.
D. In human body, apoptosis is a normal physiological process.
97. The following statement about the relationship between hormones and behavior is correct.
A. A hormone can only affect one kind of behavior D. The process of hormone starting behavior is independent of the nervous system.
C. hormone levels are sometimes affected by behavior. D. the regulatory effect of hormones on behavior is related to genetic factors.
98. The frequencies of genotypes in four different populations are as follows. Which are the balanced populations?
A. 0.36 aluminum: 0.48 aluminum 2:0. 16a2a 2 b. 0.25 aluminum: 0.50 aluminum 2:0.25A2A2
c . 0.04 a 1Al:0.32 ala 2:0.64 a2 a2 d . 0.09 alal:0.49 ala 2:0.42 a2 a2
99. Of the following descriptions of nucleic acids, the correct one is correct.
A. nucleic acids have both phosphate groups and alkaline groups, so they are amphoteric electrolytes. Phosphoric acids are usually acidic because they are very acidic.
B. hypochromic effect will appear after denaturation of nucleic acid, but the color increasing effect will appear when renaturation.
The highest ultraviolet absorption peak of nucleic acid is around 280nm.
The higher the content of D. G-C base pairs, the higher the ionic strength of the medium and the higher the Tm value of nucleic acid.
100. Which of the following statements about the characteristics or functions of sympathetic nerves is correct?
A. controlled by consciousness B. inhibiting gastrointestinal peristalsis C. promoting pupil dilation D. thoracic segment originating from spinal cord
2009 National Biology Competition for Middle School Students (Preliminary Competition)
Answers to municipal trial questions in Hebei Province
The total score of this paper is 120.
1. Multiple choice questions (there is only one correct answer to each small question, 1 point, 80 points for each question * * *)
1-5 CDCDD 6- 10 ADDDA 1 1- 15 DDBCD 16-20 acbab
2 1-25 ACCBC 26-30 DCDCD 3 1-35 BDBCA 36-40 BACAB
4 1-45 CBBCD 46-50 AABCD 5 1-55 ABBDB 56-60 BBADB
CDAAC
Two, indefinite multiple-choice questions (each question has one or more correct answers, multiple or less choices do not score, each question 2 points, ***40 points)
8 1-85 BD AD AC BCD AD 86-90 ACD ABC ABCD ABD ABCD
9 1 ~ 95 AC CD BD ABD ABC 96— 100 BD CD ABC AD BC
There are many online, you can find them yourself.