Tag: mendel's law of inheritance
Questions Related to mendel's law of inheritance
A gene is
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Synonym of chromosomes
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Composed of mRNA
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A specific segment of nucleotides of DNA
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Having only those nucleotides required to synthesize a protein
A gene is a sequence of nucleotides along a DNA strand - with 'start' and 'stop' codons and other regulatory elements - that specifies a sequence of amino acids that are linked together to form a protein.
Which of the following is true regarding genes?
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Gene is a unit of heredity which is transferred from a parent to offspring
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Gene is a distinct sequence of nucleotides forming part of a chromosome
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Gene is the order which determines the order of monomers in a polypeptide
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All of the above
- Genes are basic unit of heredity present on the chromosome.
- They are made up of DNA hence they are sequence of nucleotides.
- These orders of nucleotides in DNA later determine the sequence of polypeptide chain formed from them during translation.
- So, the correct option is 'All of the above'.
Which of the following is an INCORRECT statement regarding genetic material?
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Genes are made up of DNA
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Chromatin is made up of DNA
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Histones are proteins to which chromatin is bound
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DNA is made up of genes
In biology, a gene is a sequence of DNA or RNA that codes for a molecule that has a function. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. However the inverse is incorrect.
Which of the following part of DNA contains genes?
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Junk DNA
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Coding DNA
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Whole DNA
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Any of the above
Gene is present in the coding region of the DNA. In eukaryotes, gene is made up of both introns and exons. So, the correct option is "Coding DNA".
How many genotyprs are possible from a across between the parent $RR$ and $rr$ ?
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Four
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One
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Three
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Two
In pea plants, the long-stem trait $(L)$ is dominant and the short-stern trait $(I)$ is recessive. Two pea plants were crossed, producing seeds that yielded 165 long-stem plants and 54 short-stem plants. The genotypes of the parent plants were most likely
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$LI$ and $LL$
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$LI$ and $LI$
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$II$ and $II$
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$LL$ and $II$
- The ratio of long stem plants to short stem plants among the progeny is 165:54 which means it has a ratio of 3:1. This ratio is possible if the parents are heterozygous in nature which after the cross will produce homozygous tall, heterozygous tall and homozygous dwarf offsprings.
- As the heterozygous offspring expresses the dominant allele, they will also be tall. This is a classic example of the monohybrid ratio that produces a ratio of 3:1 in the F2 generation of pure line parents.
Gene library or DNA library has collection of
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DNA and RNA
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Any one type of gene of Organism
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c DNA only
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All possible genes of all organisms
- A Gene library or DNA library is a comprehensive collection of cloned DNA fragments from a cell, tissue, or organism.
- DNA libraries can be used to isolate a specific gene of interest as they generally include at least one fragment that contains the gene.
- Hence Gene library or DNA library has a collection of c DNA only.
- So, the correct answer is 'c DNA only'.
When a cross is made between two parents with respect to a single character, it is called as
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Dihybrid
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Monohybrid
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Trihybrid
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None of these
- A monohybrid cross is a type of cross between two individuals with different alleles at one genetic locus of interest.
- The character(s) being studied in a monohybrid cross are governed by two or multiple alleles for a single locus.
- A dihybrid cross is a cross between two pure lines (varieties, strains) that differ in two observed traits. In Mendelian sense, between the alleles of both these loci, there is a relationship of complete dominance - recessive.
- Trihybrid cross is the mating of two individuals, organisms, or strains that have different gene pairs that determine three specific traits or in which three particular characteristics or gene loci are being followed.
A cross in which a single pair of contrasting characters is studied at a time is called as_____________
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Monohybrid cross
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Dihybrid cross
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Trihybrid cross
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Tetrahybrid cross
- A monohybrid cross is a mating between two individuals with different alleles at one genetic locus of interest. The cross involves a single pair of contrasting characters.
Mendel formulated the law of purity of gametes on the basis of _______________
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Dihybrid cross
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Monohybrid cross
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Back cross
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Test cross
- The monohybrid cross-refers to inheritance of singe contrasting trait by two parents at a time. For example, a cross of tall (T) and dwarf (t) pea plants (TT x tt). Mendel observed that monohybrid cross between two pure breeding varieties yields $F _1$ generation which exhibits the dominant trait; although factor for a recessive trait is present in $F _1$ hybrids. Self-fertilization of $F _1$ generation obtains $F _2$ generation which exhibits both dominant and recessive traits in the 3:1 phenotypic ratio. This laid the foundation of the law of purity of gametes which states that the two factors for a trait, present together in a heterozygous individual, do not get mixed and are separated during gametogenesis.