Genetics and heredity
边玩边学
回答这些题目来赚取能量，然后钓鱼探索。无需账号。
练习题
免费预览——61 题中的 8 题。注册即可查看全部。
1.What is the molecule that encodes genetic information and is passed from parents to offspring?
Easy- ADNA
- BRNA
- CProtein
- DLipid
2.The complete set of observable traits of an organism is called its genotype.
EasyTrue or false?
3.Which of the following best describes alleles?
Easy- ADifferent forms of the same gene
- BThe physical appearance of an organism
- CThe complete set of genes in an organism
- DSegments of DNA that code for proteins
4.Which of the following are true about DNA? (Select all that apply)
Medium- AIt is a double-stranded molecule.
- BIt contains four types of bases.
- CIt is found only in the nucleus.
- DIt can be copied before cell division.
5.Match each term with its correct description.
Easy- Genotype
- Phenotype
- Allele
- Genetic makeup of an organism
- Observable characteristics of an organism
- Alternative form of a gene
6.Arrange the following in order from smallest to largest in terms of genetic structure.
Medium- Gene
- Chromosome
- DNA molecule
- Nucleotide
7.Epigenetic inheritance involves changes in the DNA sequence that are passed to offspring.
MediumTrue or false?
8.Which of the following is an example of a trait influenced by both genotype and environment?
Medium- AEye colour
- BBlood type
- CSuntanned skin
- DSickle cell anaemia
更多题目
9.Which of the following are true about chromosomes? (Select all that apply)
Medium- AChromosomes are made of DNA and protein.
- BHumans have 23 pairs of chromosomes.
- CChromosomes are located in the cytoplasm.
- DHomologous chromosomes carry the same genes at the same loci.
- EChromosomes are only visible during cell division.
10.Match each genetic term with its correct definition.
Medium- Gene
- Allele
- Locus
- Genotype
- Specific location of a DNA sequence on a chromosome
- Different form of a gene
- Genetic makeup of an organism
- Segment of DNA that codes for a functional unit
11.What is the name of the process by which DNA is copied before a cell divides?
Easy- ATranscription
- BTranslation
- CReplication
- DMutation
12.A mutation in a gene always results in a change in the phenotype of the organism.
EasyTrue or false?
13.Which of the following best describes the relationship between genes and DNA?
Easy- AGenes are made of DNA and code for proteins.
- BDNA is made of genes.
- CGenes and DNA are unrelated.
- DGenes are found in the cytoplasm, DNA in the nucleus.
14.Which of the following are examples of epigenetic inheritance? (Select all that apply)
Hard- ADNA methylation patterns
- BChanges in DNA sequence
- CRNA interference
- DPrion protein conformation
15.Arrange the following events of protein synthesis in correct order.
Medium- Transcription
- Translation
- mRNA leaves nucleus
- Amino acids join to form polypeptide
16.Which of the following statements about the genetic code are correct? (Select all that apply)
Medium- AThe genetic code is universal, meaning the same codon codes for the same amino acid in all organisms.
- BThe genetic code is degenerate, meaning that most amino acids are coded for by more than one codon.
- CThe genetic code is overlapping, so that each base is part of three different codons.
- DThe genetic code is read in groups of three bases called codons.
- EThe genetic code includes start and stop codons that initiate and terminate translation.
17.In a cross between two heterozygous individuals, the expected phenotypic ratio of dominant to recessive offspring is always 3:1.
MediumTrue or false?
18.Arrange the following events in the correct order for the formation of a gamete through meiosis.
Medium- Crossing over occurs between homologous chromosomes
- Homologous chromosomes separate to opposite poles
- DNA replication occurs before meiosis begins
- Sister chromatids separate to form four haploid cells
19.The diagram below shows a genetic cross for seed shape in pea plants (R = round dominant, r = wrinkled). What is the probability that an offspring will be homozygous dominant?
Medium- A0.25
- B0.5
- C0.75
- D1.0
20.A scientist crosses a plant with red flowers (RR) and a plant with white flowers (rr). The F1 generation all have pink flowers. Which inheritance pattern does this illustrate?
Medium- AComplete dominance
- BIncomplete dominance
- CCodominance
- DSex linkage
21.In a genetics experiment, a student crosses two heterozygous pea plants (Pp × Pp) for flower colour (P = purple dominant, p = white). They count 200 offspring and observe 148 purple and 52 white flowers. Which statistical test would be most appropriate to determine if the deviation from the expected 3:1 ratio is significant?
Medium- AChi-squared test
- Bt-test
- CStandard deviation
- DCorrelation coefficient
22.A student performs a cross between a homozygous dominant tall pea plant (TT) and a homozygous recessive short pea plant (tt). All F1 offspring are tall. The student then crosses two F1 plants. What proportion of the F2 offspring are expected to be homozygous dominant?
Medium- A1/4
- B1/2
- C3/4
- D1/1
23.In a monohybrid cross, the chi-squared test is used to determine if the observed phenotypic ratio significantly differs from the expected ratio.
EasyTrue or false?
24.Which of the following are necessary conditions for the Hardy-Weinberg equilibrium to hold in a population? (Select all that apply)
Medium- ANo mutations
- BRandom mating
- CNatural selection
- DLarge population size
25.Match each genetic term with its correct description.
Easy- Allele
- Locus
- Genotype
- Phenotype
- Alternative form of a gene
- Specific position of a gene on a chromosome
- Genetic makeup of an organism
- Observable characteristics of an organism
26.Arrange the following steps in the correct order for a typical monohybrid cross experiment from start to finish.
Medium- Cross parental plants
- Observe F1 phenotypes
- Self-cross F1 plants
- Count F2 phenotypes
- Analyze results with chi-squared test
27.In a dihybrid cross, if the genes are linked (i.e., located on the same chromosome), the phenotypic ratio in the F2 generation is most likely to:
Hard- ADeviate significantly from 9:3:3:1
- BBe exactly 9:3:3:1
- CBe 1:1:1:1
- DBe 3:1
28.What is the name of the molecule that encodes genetic information and is passed from parents to offspring?
Easy- ADNA
- BRNA
- CProtein
- DLipid
29.In a monohybrid cross between two heterozygous parents (Bb × Bb), what is the probability that an offspring will be homozygous dominant?
Easy- A1/4
- B1/2
- C3/4
- D0
30.Arrange the following steps in the correct order for the process of meiosis that leads to genetic diversity.
Medium- Crossing over occurs between homologous chromosomes
- Homologous pairs separate
- Sister chromatids separate
- DNA replication before meiosis begins
31.Which of the following are true about the relationship between genes and DNA? (Select all that apply)
Medium- AA gene is a segment of DNA that codes for a functional product.
- BDNA is made up of genes only.
- CGenes are located on chromosomes.
- DAll DNA in a cell codes for proteins.
32.Which of the following statements about the relationship between genotype and phenotype are correct? (Select all that apply)
Hard- AGenotype determines phenotype entirely, with no environmental influence.
- BA single genotype can produce different phenotypes in different environments.
- CIdentical twins always have identical phenotypes.
- DEpigenetic changes can alter phenotype without changing the DNA sequence.
- EPhenotype includes both physical traits and behaviours.
33.A mutation in a somatic cell can be inherited by offspring.
EasyTrue or false?
34.A scientist crosses a plant with red flowers (RR) and a plant with white flowers (rr). The F1 generation all have pink flowers. Which inheritance pattern does this demonstrate?
Medium- AComplete dominance
- BIncomplete dominance
- CCodominance
- DSex linkage
35.In a test cross, a pea plant showing a dominant phenotype is crossed with a homozygous recessive plant. If half of the offspring show the recessive phenotype, what is the genotype of the dominant parent?
Medium- AHomozygous dominant
- BHeterozygous
- CHomozygous recessive
- DCannot be determined
36.Which of the following are necessary conditions for a population to be in Hardy-Weinberg equilibrium? (Select all that apply)
Hard- ANo mutations
- BRandom mating
- CNatural selection acting on the population
- DLarge population size
- EGene flow between populations
37.In a dihybrid cross between two heterozygous individuals (AaBb × AaBb) where the genes are unlinked, the expected phenotypic ratio in the F2 generation is 9:3:3:1.
MediumTrue or false?
38.Arrange the following structures in order from smallest to largest in terms of genetic organization.
Easy- Chromosome
- Gene
- DNA molecule
- Genome
39.Which of the following are true about the inheritance of traits? (Select all that apply)
Medium- AMutations in somatic cells can be passed to offspring.
- BEpigenetic inheritance can involve changes that are not due to DNA sequence.
- CBlending inheritance was proposed by Darwin and is supported by modern genetics.
- DThe environment can influence the expression of some inherited traits.
40.Complete the sentence.
EasyThe specific location of a DNA sequence within a chromosome is known as a ____.
41.What is the term for a change in the DNA sequence that can produce new alleles?
Easy42.In a monohybrid cross between two heterozygous individuals (Bb × Bb), what is the probability (as a fraction) that an offspring will be homozygous recessive?
Easy43.Complete the sentence about inheritance.
MediumThe complete set of genes within an organism's genome is called its ____, while the observable traits are called its ____.
44.In a monohybrid cross between two heterozygous pea plants (Tt × Tt) for plant height (T = tall dominant, t = short recessive), how many offspring out of 16 are expected to be short?
Medium45.What term describes a change in the DNA sequence that can produce new alleles?
Easy46.In pea plants, tall (T) is dominant over short (t). A heterozygous tall plant is crossed with a short plant. What is the probability (as a decimal) that an offspring will be short?
Medium47.Complete the sentence:
EasyThe complete set of genes within an organism's genome is called its ____.
48.Complete the sentence about chromosomes.
EasyIn a cell, DNA is organised into structures called ____. Each human body cell contains ____ chromosomes.
49.Complete the sentence about alleles.
EasyDifferent versions of the same gene are called ____. If an organism has two identical alleles for a trait, it is ____ for that trait.
50.In a monohybrid cross between two heterozygous pea plants (Tt × Tt) for plant height (T = tall, t = short), how many offspring out of 16 are expected to be short?
Easy51.A heterozygous tall pea plant (Tt) is crossed with a short pea plant (tt). What is the probability (as a decimal) that an offspring will be tall?
Easy52.Explain why blending inheritance would have been a problem for Darwin's theory of evolution by natural selection.
Hard53.Describe how a mutation in a gene can lead to a change in phenotype.
Medium54.Explain how a test cross can be used to determine the genotype of an organism showing a dominant phenotype. Include the expected outcomes and what they reveal about the genotype.
Medium55.Explain how a test cross can be used to determine the genotype of an organism showing a dominant phenotype. Include the expected outcomes and what they reveal about the organism's genotype.
Medium56.Explain how a test cross can be used to determine the genotype of an organism showing a dominant phenotype. Include the expected outcomes and what they reveal about the unknown genotype.
Medium57.In a monohybrid cross between two heterozygous individuals (Bb × Bb), what is the probability (as a fraction) that an offspring will be homozygous recessive?
Medium- A1.25
- B2.25
- C-0.75
- D0.25
58.In a monohybrid cross between two heterozygous pea plants (Tt × Tt) for plant height (T = tall dominant, t = short recessive), how many offspring out of 16 are expected to be short?
Easy- A5
- B3
- C4
- D6
59.In pea plants, tall (T) is dominant over short (t). A heterozygous tall plant is crossed with a short plant. What is the probability (as a decimal) that an offspring will be short?
Easy- A-0.5
- B0.5
- C1.5
- D2.5
60.In a monohybrid cross between two heterozygous pea plants (Tt × Tt) for plant height (T = tall, t = short), how many offspring out of 16 are expected to be short?
Easy- A3
- B4
- C6
- D5
61.A heterozygous tall pea plant (Tt) is crossed with a short pea plant (tt). What is the probability (as a decimal) that an offspring will be tall?
Easy- A0.5
- B1.5
- C-0.5
- D2.5
闪卡
What is heredity?
Heredity is the passing on of traits from parents to offspring through asexual or sexual reproduction.
What is the study of heredity called?
Genetics.
Define genotype.
Genotype is the complete set of genes within an organism's genome.
Define phenotype.
Phenotype is the complete set of observable traits of an organism's structure and behavior.
How does the environment affect phenotype? Give an example.
Phenotype arises from the interaction of genotype with environment. For example, suntanned skin results from genotype and sunlight, and is not inherited.
What molecule encodes genetic information?
DNA (deoxyribonucleic acid).
What are the four types of bases in DNA?
Adenine, thymine, cytosine, and guanine.
What is a gene?
A portion of a DNA molecule that specifies a single functional unit.
What are chromosomes?
Long strands of DNA that form condensed structures within cells.
What is a locus?
The specific location of a DNA sequence within a chromosome.
What are alleles?
Different forms of a DNA sequence at a particular locus that vary between individuals.
How do new alleles arise?
Through mutations in DNA sequences.
What is the relationship between alleles and traits?
A mutation in a gene may produce a new allele that can affect the trait controlled by that gene, altering the phenotype.
Are most traits controlled by a single gene?
No, most traits are complex and controlled by multiple interacting genes.
What is epigenetic inheritance?
Heritable changes that cannot be explained by direct changes in DNA sequence, such as DNA methylation or RNA interference.
What problem did Darwin's theory of evolution face regarding heredity?
It lacked an underlying mechanism for heredity; blending inheritance would remove variation too quickly.
What is the role of meiosis in heredity?
Meiosis produces gametes with half the genetic material, ensuring genetic diversity through recombination.
How does fertilisation contribute to genetic diversity?
Fertilisation combines genetic material from two parents, creating unique offspring genotypes.
What is the difference between asexual and sexual reproduction in terms of heredity?
Asexual reproduction produces offspring genetically identical to the parent; sexual reproduction generates genetic variation.
What is the genome?
The complete set of genetic material (all genes) in an organism.
What are homologous chromosomes?
Chromosome pairs, one from each parent, that carry genes for the same traits at corresponding loci.
What is a mutation?
A change in the DNA sequence that can produce new alleles.