Question:
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: In an experiment, Mendel observed that the \(F_1\) progeny plants are all tall and none are dwarf.
Reason R: Stem height is a contrasting trait, with tall being dominant and dwarf being recessive.
In the light of the above statements, choose the most appropriate answer from the options given below:
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: In an experiment, Mendel observed that the \(F_1\) progeny plants are all tall and none are dwarf.
Reason R: Stem height is a contrasting trait, with tall being dominant and dwarf being recessive.
In the light of the above statements, choose the most appropriate answer from the options given below:
Assertion A: In an experiment, Mendel observed that the \(F_1\) progeny plants are all tall and none are dwarf.
Reason R: Stem height is a contrasting trait, with tall being dominant and dwarf being recessive.
In the light of the above statements, choose the most appropriate answer from the options given below:
Show Hint
The monohybrid phenotypic ratio in \(F_2\) is \(3:1\) (Tall : Dwarf), while the genotypic ratio is \(1:2:1\) (\(TT : Tt : tt\)).
The recessive trait only expresses itself under homozygous conditions (\(tt\)), which is why it disappears in the \(F_1\) generation and reappears in \(F_2\).
Updated On: Jun 26, 2026
- A is not correct but R is correct
- Both A and R are correct and R is the correct explanation of A
- Both A and R are correct but R is not the correct explanation of A
- A is correct but R is not correct
Show Solution
Verified By Collegedunia
The Correct Option is B
Solution and Explanation
Concept:
• Mendel performed monohybrid crosses to study the inheritance of single characters like stem height.
• He crossed true-breeding tall (\(TT\)) and dwarf (\(tt\)) pea plants.
• According to the Law of Dominance, in a heterozygote, one allele masks the phenotypic expression of another allele at the same locus.
• The allele that expresses itself is dominant (tall, \(T\)), and the one that is masked is recessive (dwarf, \(t\)).
Step 1: Evaluate Assertion A
Assertion A states that all \(F_1\) progeny plants are tall and none are dwarf.
This is true, as the genotype of the \(F_1\) generation is completely heterozygous (\(Tt\)), expressing the dominant tall phenotype.
Step 2: Evaluate Reason R
Reason R states that tall is dominant and dwarf is recessive.
This is also true, and this dominance is precisely why the recessive dwarf trait cannot express itself in the heterozygous \(F_1\) hybrid.
Step 3: Determine if R is the correct explanation of A
The reason why the \(F_1\) progeny are all tall (Assertion) is because tall is dominant over dwarf (Reason).
Thus, R is the correct explanation of A.
• Mendel performed monohybrid crosses to study the inheritance of single characters like stem height.
• He crossed true-breeding tall (\(TT\)) and dwarf (\(tt\)) pea plants.
• According to the Law of Dominance, in a heterozygote, one allele masks the phenotypic expression of another allele at the same locus.
• The allele that expresses itself is dominant (tall, \(T\)), and the one that is masked is recessive (dwarf, \(t\)).
Step 1: Evaluate Assertion A
Assertion A states that all \(F_1\) progeny plants are tall and none are dwarf.
This is true, as the genotype of the \(F_1\) generation is completely heterozygous (\(Tt\)), expressing the dominant tall phenotype.
Step 2: Evaluate Reason R
Reason R states that tall is dominant and dwarf is recessive.
This is also true, and this dominance is precisely why the recessive dwarf trait cannot express itself in the heterozygous \(F_1\) hybrid.
Step 3: Determine if R is the correct explanation of A
The reason why the \(F_1\) progeny are all tall (Assertion) is because tall is dominant over dwarf (Reason).
Thus, R is the correct explanation of A.
Was this answer helpful?
1
2
Top NEET Botany Questions
- How many turns of Calvin cycle are required for the formation of three molecules of glucose?
- Photorespiration reaction catalyzed by RuBisCO is shown below :
\[ \text{RuBP} + \text{O}_2 \rightarrow \text{3-Phosphoglycerate} + \text{X} \] Identify "X" from the given options : - Given below are two statements :
Statement I : In gymnosperms, the male and female gametophytes remain within the sporangia.
Statement II : In gymnosperms, the seeds are not covered.
In the light of the above statements, choose the most appropriate answer from the options given below : - How many molecules of pyruvic acid are produced at the end of glycolysis from 206 molecules of glucose?
Match List-I with List-II.
List-I List-II A. Fusion of protoplasms between gametes I. Meiosis B. Fusion of two nuclei II. Plasmogamy C. Generation of haploid spores III. Karyogamy Choose the correct answer from the options given below :
View More Questions
Top NEET Mendel’s Laws Of Inheritance Questions
- नीचे दो कथन दिए गए हैं : एक को अभिकथन A और दूसरे को तर्क R के रूप में नामांकित किया गया है।
अभिकथन A : एक प्रयोग में, मेंडल ने देखा कि F1 संतानें पौधे सभी लंबे थे और कोई भी बौना नहीं था।
तर्क R : लंबे होने का एक विकल्पी लक्षण है, जिसमें लंबा प्रभावी और बौना अप्रभावी होता है। - નીચે બે વિધાનો આપેલ છે: એકને Assertion A અને બીજાને Reason R તરીકે લેબલ કરવામાં આવ્યા છે.
Assertion A: એક પ્રયોગમાં, મેન્ડેલે જોયું કે F₁ પેઢીના છોડ તમામ ઊંચા હતા અને કોઈ પણ ટૂંકા નહોતા.
Reason R: સ્ટેમની ઊંચાઈ વિરોધાભાસી લક્ષણ છે, જેમાં ઊંચું પ્રભાવી (dominant) અને ટૂંકું પ્રતિકારી (recessive) છે.
ઉપરોક્ત વિધાનોના આલોકમાં, સૌથી યોગ્ય વિકલ્પ પસંદ કરો:
Top NEET Questions
- A $100.0\, mL$ dilute solution of $Ag ^{+}$is electrolysed for $15.0$ minutes with a current of $1.25 \,mA$ and the silver is removed completely. What was the initial $\left[ Ag ^{+}\right]$?
- The time constant of C-R circuit is
- The chronological order of human evolution from early to the recent is
- The correct Boolean operation represented by the circuit diagram drawn is :
- The driver of a car travelling with speed $30\, m/sec$ towards a hill sounds a horn of frequency $600\, Hz.$ If the velocity of sound in air is $330\, m/s,$ the frequency of reflected sound as heard by driver is
View More Questions