NCERT - PRINCIPLES OF INHERITANCE & VARIATION - 24-25

What is the term for genes that code for contrasting traits?

The phenotype of a plant with a genotype Tt will be dwarf.

What represents the alleles for height in pea plants?

In true breeding plants, the allelic pairs are said to be _____ for height.

Match the genotype with its corresponding phenotype:

Which of the following represents a homozygous genotype for height?

Mendel found that in a pair of dissimilar traits, one trait can dominate the other.

What is the result when alleles IA and IB are present together?

What is the phenotype of a plant with the genotype Tt?

Allele i produces a form of sugar.

How many phenotypes are possible for the ABO blood types?

What was one of the contrasting traits studied by Mendel in pea plants?

Mendel's experiments used a small sampling size to increase the credibility of his data.

The phenomenon where two different alleles express themselves equally is called ______.

Match the allele with its corresponding blood type:

What is a true-breeding plant?

What type of inheritance is shown in the example of starch synthesis in pea seeds?

Mendel conducted _____ experiments using several true-breeding pea lines.

Match the following virtues with their corresponding contrasting traits studied by Mendel:

An individual can possess more than two alleles for a single gene at one time.

Which of these traits is NOT one of the contrasting traits that Mendel studied?

What are the genotypes of blood type O?

Mendel's findings were based solely on theories without any experimental support.

What did Mendel's experiments contribute to the understanding of genetics?

What is the phenotypic ratio among the plants in the F2 generation?

All F1 plants have the same genotype of Tt.

What are the genotypes produced from the self-pollination of F1 plants?

The dominant phenotype expressed in the F1 generation is ______.

What is the genotypic ratio in the F2 generation?

The F2 generation contains only dominant tall plants.

What conclusion did Mendel draw about the genotype of the dwarf plants?

Which type of allele is usually associated with producing a non-functional enzyme?

The F1 generation in co-dominance resembles only one parent.

What type of inheritance involves multiple genes controlling a trait?

What are the three alleles that control the ABO blood grouping in human beings?

Pleiotropic genes can cause multiple phenotypic expressions from a single gene.

Name a classic example of a polygenic trait in humans.

In a monohybrid cross, the presence of __________ determines the phenotype when paired with a recessive allele.

Match the allele types with their characteristics:

The genotype with all dominant alleles for skin color is represented as ______.

Which of the following traits in humans is considered a result of pleiotropy?

What happens when a modified allele produces a normal enzyme?

In incomplete dominance, the F1 generation presents traits that are a mix of both parents.

Match the following terms with their definitions:

The height of individuals is an example of monogenic inheritance.

What is the result when the recessive trait is expressed due to a non-functional enzyme?

What is the role of the gene that causes phenylketonuria?

What discovery allowed scientists to observe cell division more clearly in the early 1900s?

Mendel's work was recognized immediately after he published his findings in 1865.

What parallel did Walter Sutton and Theodore Boveri observe between chromosomes and genes?

Mendel's concept of genes as stable and discrete units that controlled traits was initially _____ by many biologists.

Match the following scientists with their contributions related to Mendel's work:

Which of the following best describes chromosomes?

Mendel's mathematical approach helped clarify biological phenomena in his time.

What chromosomes determine female characteristics in birds?

What important concept did Mendel devise about alleles?

Human males produce only one type of gamete carrying either an X or Y chromosome.

What is the genetic composition of the zygote if the ovum fertilizes with a sperm carrying an X chromosome?

In human beings, the sex determining mechanism is of the _____ type.

Match the type of gamete production with their respective sex determination mechanism:

What is the probability of having a female child during each pregnancy in humans?

Females in humans can produce two types of gametes.

What degree did James Dewey Watson obtain in 1947?

What are the sex chromosomes present in human males?

Francis Crick was born in Chicago, Illinois.

What significant discovery did Watson and Crick propose in March 1953?

Crick completed his Ph.D. in _____ on a thesis about X-ray diffraction.

Match the scientist to their contribution:

What influenced Francis Crick's career significantly?

James Watson and Francis Crick received the Nobel Prize for their work on the DNA structure in 1962.

What field of science addresses questions related to inheritance and variation in organisms?

Which genotype results from self-pollination of F1 plants of genotype Tt?

The phenotype of a plant with the genotype TT can be distinguished from that of a plant with the genotype Tt.

What is the phenotypic ratio of tall to dwarf plants in the F2 generation?

The dominant allele for height in pea plants is represented by the letter _____.

Match the genotype with its corresponding phenotypic expression:

What conclusion can be drawn about the genotype of dwarf plants?

All F1 plants from the Tt genotype are dwarf.

How did Mendel determine the genotype of dwarf plants from his experiments?

Which column in the comparison represents chromosomes?

Independent assortment allows chromosome pairs to segregate in a way that one pair affects the segregation of another pair.

What is the significance of the chromosomal theory of inheritance?

During Anaphase of meiosis I, genetic variation is introduced through __________ of chromosome pairs.

Match the following concepts with their descriptions:

Which of the following best describes Drosophila melanogaster?

The life cycle of Drosophila melanogaster can be completed in approximately __________.

Thomas Hunt Morgan was instrumental in experimentally verifying the chromosomal theory of inheritance.

What phenotype does the F1 generation exhibit in the case of incomplete dominance with red and white flowered plants?

In incomplete dominance, the F2 generation shows a 3:1 ratio of phenotypes.

What is the genotypic ratio of the F2 generation from the self-pollination of the F1 generation in the example of incomplete dominance?

In the case of Antirrhinum sp., true-breeding red flowers have the genotype _____ and true-breeding white flowers have the genotype _____.

Match the genotype with the corresponding phenotype in the context of incomplete dominance.

How are alleles expressed in a heterozygote in the case of incomplete dominance?

Alleles can be completely dominant, recessive, or incompletely dominant.

Define incomplete dominance.

What is the phenotype of a plant with a genotype of TT?

Alleles are identical forms of a gene.

What does the term 'homozygous' refer to in relation to alleles?

In a monohybrid cross, the genotype of the F1 generation is typically represented as _____ when one allele is dominant.

Match the genotype with its corresponding description:

Which statement best describes the relationship between dominant and recessive traits?

The phenotype of the F1 generation will always reflect the recessive trait.

What allele represents the recessive trait for height in pea plants?

What is the karyotype of an individual with Klinefelter’s Syndrome?

Individuals with Turner’s Syndrome have normal ovaries.

What term describes the phenomenon where one trait is completely dominant over another?

A female with Turner’s Syndrome has a karyotype of _____ with X0.

Match the genetic disorders with their characteristics:

Which of the following statements about Mendel's work is correct?

All individuals with Klinefelter’s Syndrome express exclusively feminine traits.

What is a common characteristic of individuals with Klinefelter’s Syndrome?

What determines the sex of honey bees?

Honey bee males have the same number of chromosomes as females.

What is the total number of chromosomes for a female honey bee?

Males develop from ______ eggs in honey bees.

What type of mutation results in the alteration of a single base pair of DNA?

Match the type of mutation with its description:

Males in honey bees do not have a father.

Name a classical example of a mutation affecting phenotype.

In XO type of sex determination, which of the following statements is true?

In humans, males have a pair of XX chromosomes.

What is the sex determination mechanism present in many birds?

In the XX-XY sex determination system, the male is referred to as ______.

Match the following species with their corresponding sex determination system:

Which sex chromosome pair do females possess in both humans and Drosophila?

All male birds have the same chromosomes as female birds.

In sex determination systems, chromosomes that are not involved in sex determination are termed ______.

What is the term used to describe agents that induce mutations?

UV radiation is considered a mutagen.

What process is used to analyze the inheritance pattern of traits in humans?

An alteration in the genetic material is referred to as a _____.

Which of the following best describes the purpose of pedigree analysis?

Changes in DNA are always harmful to the organism.

What role does DNA play in genetics?

Which of the following disorders is an example of a Mendelian disorder?

Colour blindness is transmitted from father to daughter.

What is the pattern of inheritance observed for Haemophilia?

The chance of a son being color blind if his mother is a carrier is ______ percent.

Match the following Mendelian disorders with their characteristics:

Which statement is true about the inheritance of Mendelian disorders?

Mendelian disorders can be identified using pedigree analysis.

Name a common Mendelian disorder that affects the ability to clot blood.

Which of the following statements best describes the Law of Independent Assortment?

Linked genes are genes that assort independently from one another.

What are the male and female sex chromosomes in humans?

Down’s syndrome is caused by _____ of chromosome 21.

Which type of mutation involves a change in a single base pair?

Match the following genetic disorders with their descriptions:

What is the chromosomal configuration in females in chickens?

Phenotypes express genetic traits regardless of the underlying genotype.

What does the Law of Dominance state?

In a test cross, a dominant phenotype is crossed with a homozygous dominant parent.

What did Morgan observe about the F2 ratio in his dihybrid crosses?

All genes located on the same chromosome show tight linkage and minimal recombination.

What ratio is typically observed in the F2 generation of a monohybrid cross?

The process of determining the genotype of an organism by crossing it with a recessive organism is known as a _____ cross.

What term did Morgan use to describe the physical association of genes on a chromosome?

Match the components of Mendel's Laws with their descriptions:

The genes white and yellow in Drosophila showed only _____ percent recombination.

Match the following pairs of genes with their recombination percentages:

Which statement correctly describes an allele?

The Law of Segregation states that both alleles of a gene blend together in gametes.

Which of the following statements about the dihybrid crosses in Drosophila is true?

Alfred Sturtevant used recombination frequency to map gene positions on chromosomes.

In a monohybrid cross involving tall (T) and dwarf (t) plants, what are the possible gametes produced by a heterozygous plant?

What was the primary method Morgan used to study sex-linked genes in Drosophila?

All F1 generation plants exhibit dwarf characteristics.

What genotype represents a true-breeding dwarf plant?

The ratio of genotypes TT, Tt, and tt obtained from self-pollination is _____ : _____ : _____

Match the genotype with its phenotypic expression:

What would Mendel expect to occur if he self-pollinated a tall F2 plant?

The F2 generation contains only genotype Tt.

What does the symbol 'T' represent in the context of plant height?

Which of the following disorders is primarily an X-linked recessive disorder?

Mendelian disorders can only be dominant traits.

What type of genetic analysis is used to trace the inheritance of Mendelian disorders in families?

Haemophilia is an example of a _____ disorder.

What is the chance of a son of a carrier mother being colour blind?

Males have two X chromosomes, which increases the likelihood of being affected by X-linked disorders.

Name one common Mendelian disorder that affects the blood's ability to clot.

What karyotype is associated with Klinefelter's Syndrome?

Individuals with Turner’s Syndrome have normally developed ovaries.

List one primary feature of individuals diagnosed with Klinefelter's Syndrome.

The presence of an additional copy of the X chromosome results in _____ development in Klinefelter's Syndrome.

Which of the following statements describes Mendel's Law of Segregation?

Match the following syndromes with their characteristics:

Mendel's principles of inheritance are applicable to both plants and animals.

What phenomenon results in some characters being expressed in homozygous conditions but not in heterozygous conditions?

What type of plants did Mendel primarily use for his experiments?

Mendel's experiments had a small sampling size which decreased the credibility of the data he collected.

Mendel selected ___ true-breeding pea plant varieties for his studies.

Which of the following is one of the contrasting traits studied by Mendel?

Match the following traits with their contrasting characteristics:

What general rules did Mendel's results come to point towards?

Mendel's work had no experimental support before being acknowledged in genetics.

What theory did Sutton unite with Mendelian principles regarding inheritance?

Independent assortment of chromosomes occurs during metaphase II of meiosis.

What organism did Thomas Hunt Morgan use in his genetics experiments?

During gamete formation, chromosomes from each pair are __________ to gametes.

Match the following aspects of chromosomes and genes:

What is the primary purpose of a test cross?

What advantage does Drosophila melanogaster present in genetic research?

The Law of Segregation states that alleles blend together during gamete formation.

What flower color in pea plants is dominant according to Mendel's findings?

Mendel's experiments with pea plants were conducted in a natural environment without control.

What process leads to the variation produced by sexual reproduction according to the chromosomal theory of inheritance?

The expression of only one parental character in the F1 generation can be explained by the __________.

Match the following laws of inheritance with their descriptions:

What phenotypic ratio is expected in the F2 generation of a monohybrid cross?

A homozygous parent produces two different types of gametes.

Define a test cross in your own words.

Which mechanism describes males producing two different types of gametes, either with or without an X-chromosome?

In humans, females have two X-chromosomes and males have one X and one Y chromosome.

What are the two types of gametes produced by males during spermatogenesis?

In birds, females have one Z and one _____ chromosome.

What is the probability of having a male or female offspring in humans?

Match the sex determination mechanisms with the correct descriptions:

The genetic makeup of the ovum determines the sex of the child in humans.

What are the sex chromosomes present in female birds?

What is the chromosome number in male honey bees?

Honey bee males develop from fertilized eggs.

What type of sex-determination system do honey bees exhibit?

Honey bees have ____ chromosomes, while drones have ____ chromosomes.

Which of the following mutations is caused by a change in a single base pair of DNA?

Chromosomal aberrations are often found in healthy, non-cancerous cells.

Match the following types of mutations with their descriptions:

What is one classical example of a point mutation?

Haemophilia is a recessive disorder linked to the X chromosome.

What is the typical inheritance pattern of colour blindness in males?

The disorder resulting in the inability to properly metabolize phenylalanine is called _____

What percentage of males is affected by colour blindness?

A daughter of a carrier mother for colour blindness will always be colour blind.

What type of genetic traits can be determined through pedigree analysis?

In Mendel's experiments, what was the observed phenotypic ratio among the F2 generation plants?

All F1 progeny plants in Mendel's crosses were a blend of their parental traits.

What term did Mendel use to refer to the units of inheritance?

The two contrasting traits of pea plants that Mendel studied included tall and _____ plants.

Match the following traits with their respective options:

During self-pollination of the tall F1 plants, what unexpected result did Mendel find in the F2 generation?

Mendel's studies concluded that traits could blend in offspring.

What does the term 'Filial1' refer to in Mendel's experiments?

What type of gametes do males produce in male heterogamety?

In birds, males have a pair of Z-chromosomes while females have one Z and one W chromosome.

What chromosome pair is present in females in the XY sex determination system?

The sex of a child in humans is determined by the genetic makeup of the _____.

Match the following organisms with their sex determination mechanisms:

What is the probability of having a male child if an ovum fertilizes with a Y-chromosome carrying sperm?

Women are solely responsible for the sex of the child, where female children are the result of their genetic contribution.

What type of chromosomes are present in male birds according to their sex determination mechanism?

What is the dominant allele for seed shape in the described pea plant crosses?

The phenotype of the heterozygous Bb seeds is larger than the phenotype of the homozygous BB seeds.

What phenotypic ratio is observed for yellow to green seeds in the F2 generation?

In Mendel's pea plant experiments, the allele for yellow seeds is designated as _____ and the allele for green seeds is designated as _____.

Match the following seed traits with their dominant or recessive status:

What type of inheritance is illustrated by the starch grain sizes in homozygous and heterozygous pea seeds?

Which column represents chromosomes and which represents genes?

Sutton and Boveri proposed that the segregation of chromosomes leads to the segregation of genes.

What does the cross between genotype RRYY and rryy produce in the F1 generation?

What is the main organism used by Thomas Hunt Morgan to study inheritance?

Heterozygous Bb seeds produce the largest starch grains compared to other genotypes.

During ______, chromosome pairs can align independently at the metaphase plate.

What is a key characteristic of independent assortment observed during meiosis?

The life cycle of Drosophila melanogaster takes about two months to complete.

Who experimentally verified the chromosomal theory of inheritance?

What are mutagens?

Pedigree analysis is used to study the inheritance of traits in plants only.

What is DNA's role in genetics?

An alteration in the genetic material is known as a _____ .

Which of the following can cause mutations?

Each feature in an organism is controlled by multiple genes located throughout the DNA.

What is represented in a pedigree analysis?

What is the total number of chromosomes in a normal human cell?

Down's syndrome is caused by having an extra copy of chromosome 21.

What is the term for the situation where an individual has an additional chromosome?

Individuals with __________ syndrome may have short stature and other physical anomalies.

Which of the following is a common characteristic of Down's syndrome?

Match the following chromosomal disorders with their characteristics:

Monosomy refers to the presence of an additional chromosome.

What genetic feature is typically observed in individuals with Down's syndrome?

What structure did Henking name after tracing it during spermatogenesis in insects?

In the XO system of sex determination, males have an additional chromosome compared to females.

What happens to eggs fertilised by sperm that do not carry an X-chromosome?

Henking's observations led to the understanding of the _______ basis of sex-determination in insects.

What does the capital letter in gene representation signify?

Tallness is dominant over dwarfness in pea plants.

What is the genotype of a true-breeding dwarf pea plant?

In genetics, two different forms of the same gene are known as _____ .

Match the genotype with its description:

Which phenotype would a Tt plant exhibit?

Mendel's studies indicated that the genotype is the visible expression of a trait.

What term describes the physical expression of a genotype?

What does the term 'linkage' refer to in genetics?

Which statement describes how chromosomes behave during gamete formation?

Sutton and Boveri proposed that the pairing and separation of chromosomes leads to the segregation of alleles.

Morgan discovered that the F2 ratio in dihybrid crosses deviated significantly from the expected 9:3:3:1 ratio due to independent assortment.

What percentage of recombination was observed between the tightly linked genes white and yellow?

What type of organism did Thomas Hunt Morgan use for his experiments on inheritance?

The chromosomal theory of inheritance was based on the work of __________ and Boveri.

The term _____ refers to the generation of non-parental gene combinations.

Which of the following was a method used by Morgan to study sex-linked genes?

During which phase of meiosis do chromosomes align at the metaphase plate independently?

What is the primary reason for higher proportions of parental gene combinations in linked genes?

Genes and chromosomes behave in exactly the same way during inheritance.

What is the significance of independent assortment in genetics?

Who was the student of Morgan that contributed to genetic mapping?

Which of the following traits is an example of polygenic inheritance?

Pleiotropic genes can only affect a single phenotype.

What is the dominant genotype for skin color according to the described polygenic trait?

Phenylketonuria is an example of a disorder caused by a mutation in a gene that codes for ______.

Match the following traits with their descriptions:

Which of the following best describes how polygenic traits function?

The phenotype of an individual with the genotype aabbcc will have the darkest skin color.

Identify one trait in humans that exhibits pleiotropy.

What is the main result of the accumulation of phenylalanine in individuals with phenylketonuria?

Thalassemia is caused by the overproduction of hemoglobin chains.

What genetic mechanism causes phenylketonuria?

Down’s syndrome is caused by the gain of an extra copy of chromosome ______.

Match the following conditions with their descriptions:

Which type of thalassemia is associated with a defect in the alpha globin chain?

Polyploidy occurs due to the gain of a chromosome.

What is the primary cause of Turner’s syndrome?

What is the primary field of study that deals with the questions related to inheritance and variation?

James Watson was awarded the Nobel Prize in 1960.

Who were the two scientists credited with proposing the double-helical structure of DNA?

Francis Crick completed his Ph.D. in ____ on a thesis about X-ray Diffraction.

Match the following scientists with their corresponding achievements:

In what year did Watson receive his B.Sc. degree?

The study of genetics only covers questions about human inheritance.

What method did Watson and Crick utilize to arrive at their proposal for DNA structure?

In Mendel's experiments with pea plants, what does the capital letter represent when coding for traits?

In a monohybrid cross, Tt genotype will result in a dwarf phenotype.

What is the phenotypic outcome when a homozygous tall plant (TT) is crossed with a homozygous dwarf plant (tt)?

In genetics, a pair of dissimilar alleles is referred to as _____.

Which term is used to describe the physical appearance of an organism regarding a specific trait?

Alleles are identical forms of a gene found at the same locus on homologous chromosomes.

What was the key finding of Mendel regarding dominant and recessive traits?

What term refers to the physical association of genes on a chromosome?

Alfred Sturtevant determined the distance between genes based on recombination frequencies.

What fruit fly species did Morgan use for his dihybrid crosses?

Match the following terms with their corresponding definitions:

What observed ratio deviated from the expected 9:3:3:1 ratio in Morgan's experiments?

Morgan's crosses indicated that genes on different chromosomes segregate independently.

What was the main observation made by Morgan regarding parental gene combinations?

What determines the sex of the child in humans?

Females produce two different types of gametes in humans.

In humans, males possess one _____ chromosome and one _____ chromosome.

Match the sex determination mechanisms with their descriptions:

What percentage of sperm produced by males carries the Y chromosome?

There is an equal probability of fertilization resulting in male or female offspring.

Which chromosomes do female humans have?

Pleiotropic genes can affect multiple traits based on a single genetic mutation.

What are the dominant alleles for skin color as described in the content?

The condition caused by a mutation in the gene coding for phenyl alanine hydroxylase is known as ______.

Match the following examples with their type of inheritance:

In polygenic inheritance, how does the contribution of each allele affect the phenotype?

Human skin color is determined by a single gene.

What range of skin colors is seen in humans, and what factors influence this range?

What is the karyotype associated with Klinefelter's Syndrome?

Individuals with Turner’s Syndrome have a normal number of X chromosomes.

What is a notable physical characteristic of individuals with Klinefelter’s Syndrome?

Mendel proposed the principles of inheritance known as _______.

Match the following genetic terms with their descriptions:

Which of the following best describes the Law of Segregation?

Incomplete dominance occurs when one allele fully masks the expression of another.

What condition leads to the development of rudimentary ovaries in Turner’s Syndrome?

What structure did Henking trace during spermatogenesis in insects?

Sperms fertilized by eggs with no X-chromosome will result in males.

What type of sex determination mechanism is observed in a large number of insects?

Henking's observations contributed to the understanding of the ____-chromosome's role in sex determination.

Which of the following statements about alleles is true?

In Mendel's experiments, the phenotype of the Tt genotype was not different from that of the TT genotype.

What does the term 'phenotype' refer to in the context of genetics?

The alleles TT and tt represent _____ genotypes for height in pea plants.

Match the following genotypes with their corresponding characteristics:

Which of the following accurately describes Mendel's dominant and recessive factors?

Individuals with the genotype Tt are considered homozygous for height.

What is the genotype of a true-breeding dwarf pea plant for height?

What was one reason Mendel's work on inheritance went unrecognized until 1900?

Mendel's theory of inheritance included the concept that alleles blend together to form new traits.

Name one advancement that helped rediscover Mendel's results in the early 1900s.

Mendel's experiments suggested that factors, which we now call _____, were discrete units controlling traits.

Match the following scientists with their contributions:

In which year did Mendel publish his work on inheritance?

Chromosomes are observed to double and divide just before cell division.

What did Walter Sutton and Theodore Boveri note about the behavior of chromosomes?

What phenotypic ratio is commonly derived from a dihybrid cross involving seed color and seed shape?

Mendel's Law of Independent Assortment states that the segregation of one pair of alleles is dependent on the segregation of another pair.

How many different types of gametes are produced in a dihybrid cross involving RrYy?

Based on Mendel's cross, the genotypes of the gametes can be expressed as ______.