What are the Top 04 1st-semester question papers and answers for 9th-grade Biology? What are the rights of 9th-grade students in Vietnam when studying Biology?
What are the Top 04 1st-semester question papers and answers for 9th-grade Biology?
Download Top 04 1st-semester question papers and answers for 9th-grade Biology
Students may refer to the following Top 04 1st-semester question papers and answers for 9th-grade Biology:
1st-semester question papers and answers for 9th-grade Biolog
1. A gene on a double-stranded DNA has 120 helical turns. How many nucleotides does this gene have?
a. 3600
b. 1200
c. 120
d. 2400
2. Let A, T, G, X be the respective amounts of corresponding nucleotides on a double-stranded DNA molecule. According to the complementary principle, which expression below is correct?
a. A + T = G + X
b. A/X = G/T
c. X + T = A + G
d. X - G = A + T
3. Which mutation below does not change the number of nucleotide types in the gene?
a. Adding one pair of A - T
b. Replacing A – T pair with G - X pair
c. Losing one pair of G - X
d. Losing one pair of A – T and adding 2 pairs of G - X
4. Which method can help us determine the role of the environment and genotype in the formation of traits?
a. Reciprocal cross
b. Pedigree analysis
c. Inducing artificial mutations
d. Study of identical twins
5. Which of the following traits is dominant in humans?
a. Long eyelashes
b. Straight nose
c. Even teeth
d. All of the above options are correct
6. What role does a hormone play?
a. Carries genes, determines the physical and chemical properties in the cell.
b. Structures the organelles within the cell.
c. Catalyzes the metabolic processes in the cell and body.
d. Regulates the metabolic processes in the cell and body.
7. A chromosome has the gene sequence XYZT. After mutation, the chromosome has the gene sequence: XYZTZT. What type of mutation is this?
a. Gene mutation
b. Chromosome fragment duplication
c. Chromosome fragment inversion
d. Chromosome fragment deletion
8. Chromosomes exist singly in which type of cell?
a. Primitive germ cell
b. Somatic cell
c. Gamete
d. Mature germ cell
9. What is the primary cause of structural chromosome mutations?
a. Change in light intensity
b. Sudden change in the living environment
c. Effects of physical and chemical agents from the environment
d. Intracellular physiological changes
10. Genes and proteins are linked through an intermediary molecule, what is it?
a. tRNA
b. mRNA
c. rRNA
d. Ribosome
B. Essay
1. Compare and contrast mitosis and meiosis (4 points)
2. The codon sequence of a gene segment is as follows:
…– T – A – X – G – T – T – A – G – X – …
This gene segment undergoes a mutation. Write the mRNA strand aggregated from this gene segment in the case where the gene segment loses a nucleotide pair at the third position from the left in the sequence under review. (1 point)
3. Why are gene mutations often harmful to the organism itself? (1 point)
Answers
A. Multiple Choice
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d. 2400 (Each helical turn on double-stranded DNA has 20 nucleotides. Thus, this gene has: 20.120 = 2400 nucleotides)
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c. X + T = A + G (since A links with T and vice versa, the number of A = T, similarly, the number of G = X, so X + T = A + G)
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b. Replacing A – T pair with G - X pair (replacement thus does not change the quantity)
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d. Study of identical twins (Since twins have identical genotypes, if any traits differ due to living in different conditions, it indicates that trait is greatly influenced by the environment and vice versa)
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a. Long eyelashes
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d. Regulates the metabolic processes in the cell and body.
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b. Chromosome fragment duplication
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c. Gamete (carries half the chromosomes of the mature germ cell (2n) thus having a haploid set of chromosomes (n) meaning the chromosomes exist singly)
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c. Effects of physical and chemical agents from the environment
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b. mRNA
B. Essay
1. Compare and contrast mitosis and meiosis
A. Similarities:
- Both are processes of cell division involving spindles: Chromosomes divide first, followed by cytoplasmic division (0.25 points)
- Both go through 4 phases: prophase, metaphase, anaphase, telophase, with similar sequences regarding chromosome status and movement through phases (especially mitosis and meiosis 2) (0.25 points)
B. Differences:
| Comparison Criteria | Mitosis | Meiosis |
| Type of cells where it occurs | Primitive germ cells and somatic cells | Mature germ cells (0.5 points) |
| Number of DNA replications | 1 time | 2 times (0.25 points) |
| Number of cell divisions | 1 time | 2 times (0.25 points) |
| Sequence | - Metaphase: Chromosomes align in a single row at the equatorial plane of the spindle - Anaphase: From double chromosomes split into single chromosomes, each moving to an opposite pole of the cell - Telophase: Division of cytoplasm forming daughter cells that retain the diploid chromosome set 2n in a single state |
- Metaphase 1: Double chromosomes align in two rows at the equatorial plane (0.5 points) - Anaphase 1: Each double chromosome in homologous pairs moves towards one pole of the cell (0.5 points) - Telophase 1: Division of cytoplasm creating daughter cells with a haploid chromosome set n in a double state (0.5 points) |
| Result | From one parent cell, two daughter cells are created with the same chromosome set as the parent (2n) | From one parent cell (2n), four daughter cells are generated, each with a haploid chromosome set (n) (0.5 points) |
| Significance | Helps maintain the characteristic chromosome set of the species across cell and organism generations | Along with fertilization, helps maintain the species' chromosome set across organism generations in sexually reproducing organisms (0.5 points) |
2. The codon sequence of a gene segment is as follows:
…– T – A – X – G – T – T – A – G – X – …
After mutation processing, losing a nucleotide pair at the third position, the sequence will be:
…– T – A– G – T – T – A – G – X – … (0.5 points)
The mRNA synthesis follows the complementary principle: A pairs with U, G pairs with C, C pairs with G, and T pairs with A. The mRNA sequence will be:
…– A – U– X – A – A – U – G – X – … (0.5 points)
- Gene mutations expressed in the phenotype are generally harmful to the organism itself because they disrupt the harmonious unity in a genotype long-maintained through natural selection and cause disturbances in protein synthesis (which determines organism traits) (1 point)
*Note: Information is for reference only./.
What are the Top 04 1st-semester question papers and answers for 9th-grade Biology? What are the rights of 9th-grade students in Vietnam when studying Biology? (Image from the Internet)
What are the rights of 9th-grade students in Vietnam when studying Biology?
Under Article 35 of the Charter of Lower Secondary Schools, Upper Secondary Schools, and Multi-level Schools issued along with Circular 32/2020/TT-BGDDT, the rights of 9th-grade students when studying Biology are as follows:
- Receive comprehensive education with fairness, be provided with time, facilities, hygiene and safety to learn in class and self-learn at home, be informed of their education and training, and be able to use learning, cultural and sport equipment of their schools as per the law.
- Receive respect, protection and fair and democratic treatment, complain to their schools and education authorities about decisions concerning themselves; transfer school with legitimate reason as per existing regulations; enter school before the compulsory starting age, skip a grade and study at an age higher than the compulsory attendance age according to regulations in Article 33 of Circular 32/2020/TT-BGDDT.
- Participate in activities for development of their gifts in academic subjects, sports and art organized by their schools if able to.
- Students eligible for social benefits, disadvantaged students and gifted students may receive sponsorship or other benefits as per the law.
- Transfer school if eligible according to regulations following school transfer procedures stipulated by the Minister of Education and Training.
- Enjoy other rights as per the law.
What are the goals of education for 9th-grade Biology in Vietnam?
Pursuant to Article 2 of the Education Law 2019, the goals of education for 9th-grade Biology are as follows:
The goals of education are to educate the Vietnamese into comprehensively developed persons who possess ethics, knowledge, education, physical health, aesthetic sense and profession; to shape and cultivate one's dignity, civic qualifications and competence; to nurture one’s patriotism, national spirit, loyalty to the ideology of national independence and socialism; to develop potentials, creativity of each individual; to improve the people’s knowledge and manpower, to foster talents, satisfying the demands of the construction and defense of the Fatherland and international integration.
