Crop Botany, Geography & Agronomy Practice Questions (Q1-5) - Plant Sciences

ICAR PG Plant Sciences 29 Jun 2024Shift 1

MCQ (Single Correct) +4 −1

Chemicals that store energy for the majority of work within cells are called

वे रसायन जो कोशिकाओं के भीतर अधिकांश कार्यों के लिए ऊर्जा संग्रहीत (store energy) करते हैं, क्या कहलाते हैं?

Lipid लिपिड Protein प्रोटीन Carbohydrate कार्बोहाइड्रेट Enzyme एंजाइम

ICAR PG Plant Sciences 29 Jun 2024Shift 1

MCQ (Single Correct) +4 −1

Human beings have large-sized 'proteome'. The principal and more significant reason for this is

मानव में बड़े आकार का 'प्रोटिओम' (proteome) होता है। इसका प्रमुख और अधिक महत्वपूर्ण कारण क्या है?

Humans have an extremely large genome मानव में अत्यधिक बड़ा जीनोम होता है An individual gene of the human genome may encode many different polypeptides मानव जीनोम का एक एकल जीन कई भिन्न पॉलीपेप्टाइड्स को कूटबद्ध कर सकता है Humans are the most complex living organism मानव सबसे जटिल जीवित जीव हैं The human genome contains millions of different genes मानव जीनोम में लाखों विभिन्न जीन होते हैं

Size of Human Proteome vs. Genome:

The human genome contains approximately 20,000 to 25,000 protein-coding genes, which is surprisingly comparable to much simpler organisms like C. elegans or Arabidopsis.
However, the human proteome consists of several hundred thousand distinct proteins.
The principal biological mechanisms responsible for this vast proteomic diversity are:

Alternative Splicing: A single pre-mRNA transcript can be spliced in multiple different ways by combining different exons, producing diverse mRNA transcripts and distinct polypeptide isoforms from a single gene.
Post-Translational Modifications (PTMs): Phosphorylation, glycosylation, ubiquitination, and proteolytic cleavage further diversify functional proteins.
- Therefore, an individual gene can encode many distinct polypeptides.

Correct Answer: Option 2 (An individual gene of the human genome may encode many different polypeptides).

विस्तृत व्याख्या:

Size of Human Proteome vs. Genome (मानव प्रोटिओम की विविधता):

The human genome contains approximately 20,000 to 25,000 protein-coding genes, which is surprisingly comparable to much simpler organisms like C. elegans or Arabidopsis.
However, the human proteome consists of several hundred thousand distinct proteins.
The principal biological mechanisms responsible for this vast proteomic diversity are:

Alternative Splicing (वैकल्पिक स्प्लिसिंग): A single pre-mRNA transcript can be spliced in multiple different ways by combining different exons, producing diverse mRNA transcripts and distinct polypeptide isoforms from a single gene.
Post-Translational Modifications (PTMs): Phosphorylation, glycosylation, ubiquitination, and proteolytic cleavage further diversify functional proteins.
- Therefore, an individual gene can encode many distinct polypeptides.

Correct Answer: Option 2 (An individual gene of the human genome may encode many different polypeptides).

Explanation not matching this question? क्या व्याख्या इस प्रश्न से मेल नहीं खा रही? Report

ICAR PG Plant Sciences 29 Jun 2024Shift 1

MCQ (Single Correct) +4 −1

If an individual does not show trait even though they have the appropriate genotype, the trait is said to exhibit

यदि कोई व्यक्ति उपयुक्त जीनोटाइप (genotype) होने के बावजूद लक्षण (trait) प्रदर्शित नहीं करता है, तो इस लक्षण को क्या कहा जाता है?

Variable expressivity परिवर्तनशील अभिव्यक्तित्व Incomplete penetrance अपूर्ण प्रभाविता/प्रवेश्यता Partial dominance आंशिक प्रभाविता Co-dominance सह-प्रभाविता

Penetrance vs. Expressivity:

Penetrance: The proportion of individuals carrying a particular genotype who actually manifest the corresponding phenotype. When individuals possessing the genotype fail to express the phenotype, the trait exhibits Incomplete Penetrance.
Expressivity: The degree or intensity with which a genotype is expressed phenotypically among individuals showing the trait (e.g., polydactyly having varied numbers of extra digits).
Co-dominance: Both alleles are expressed equally in the heterozygote (e.g., AB blood group).
Partial dominance: Heterozygote has an intermediate phenotype (e.g., pink flowers in Mirabilis jalapa).

Correct Answer: Option 2 (Incomplete penetrance).

विस्तृत व्याख्या:

Penetrance vs. Expressivity (प्रवेश्यता बनाम अभिव्यक्तित्व):

Penetrance (प्रवेश्यता): The proportion of individuals carrying a particular genotype who actually manifest the corresponding phenotype. When individuals possessing the genotype fail to express the phenotype, the trait exhibits Incomplete Penetrance (अपूर्ण प्रवेश्यता).
Expressivity (अभिव्यक्तित्व): The degree or intensity with which a genotype is expressed phenotypically among individuals showing the trait (e.g., polydactyly having varied numbers of extra digits).
Co-dominance (सह-प्रभाविता): Both alleles are expressed equally in the heterozygote (e.g., AB blood group).
Partial dominance (आंशिक प्रभाविता / Incomplete dominance): Heterozygote has an intermediate phenotype (e.g., pink flowers in Mirabilis jalapa).

Correct Answer: Option 2 (Incomplete penetrance).

Explanation not matching this question? क्या व्याख्या इस प्रश्न से मेल नहीं खा रही? Report

ICAR PG Plant Sciences 29 Jun 2024Shift 1

MCQ (Single Correct) +4 −1

In humans ________ traits are much easier to identify than ________ traits. Choose the correct pair of words from the options given below for filling in the blanks:

मानव में ________ लक्षण, ________ लक्षणों की तुलना में पहचानने में बहुत आसान होते हैं। रिक्त स्थानों की पूर्ति के लिए नीचे दिए गए विकल्पों में से सही शब्द-युग्म चुनिए:

Recessive autosomal traits; X-linked traits अप्रभावी ऑटोसोमल लक्षण; X-सहलग्न लक्षण X-linked traits; Dominant autosomal traits X-सहलग्न लक्षण; प्रभावी ऑटोसोमल लक्षण X-linked traits; Recessive autosomal traits X-सहलग्न लक्षण; अप्रभावी ऑटोसोमल लक्षण Dominant autosomal traits; X-linked traits प्रभावी ऑटोसोमल लक्षण; X-सहलग्न लक्षण

Inheritance and Pedigree Analysis in Humans:

X-linked traits: In human males ($XY$), who are hemizygous for the X chromosome, any allele on the X chromosome (whether dominant or recessive) is immediately expressed in the phenotype because there is no homologous counterpart on the Y chromosome. Furthermore, X-linked traits display characteristic criss-cross inheritance (father to daughter to grandson), making them readily distinguishable and much easier to identify.
Recessive autosomal traits: These require two copies of the mutant allele (homozygosity) to be expressed phenotypically, often skip multiple generations silently via unaffected heterozygous carriers, and are much harder to track and identify without extensive pedigree and consanguinity data.

Therefore, X-linked traits are much easier to identify than recessive autosomal traits. Correct Answer: Option 3 (X-linked traits; Recessive autosomal traits).

विस्तृत व्याख्या:

Inheritance and Pedigree Analysis in Humans (मानव में वंशागति):

X-linked traits (X-सहलग्न लक्षण): In human males ($XY$), who are hemizygous for the X chromosome, any allele on the X chromosome (whether dominant or recessive) is immediately expressed in the phenotype because there is no homologous counterpart on the Y chromosome. Furthermore, X-linked traits display characteristic criss-cross inheritance (father to daughter to grandson), making them readily distinguishable and much easier to identify.
Recessive autosomal traits (अप्रभावी ऑटोसोमल लक्षण): These require two copies of the mutant allele (homozygosity) to be expressed phenotypically, often skip multiple generations silently via unaffected heterozygous carriers, and are much harder to track and identify without extensive pedigree and consanguinity data.

Therefore, X-linked traits are much easier to identify than recessive autosomal traits. Correct Answer: Option 3 (X-linked traits; Recessive autosomal traits).

Explanation not matching this question? क्या व्याख्या इस प्रश्न से मेल नहीं खा रही? Report

ICAR PG Plant Sciences 29 Jun 2024Shift 1

MCQ (Single Correct) +4 −1

________ can occur in either the first or second meiotic division to produce abnormal gametes. Choose the correct word from the below-given option to fill in the gap:

असामान्य युग्मक (abnormal gametes) उत्पन्न करने के लिए पहली या दूसरी अर्धसूत्री विभाजन (meiotic division) में ________ हो सकता है। रिक्त स्थान की पूर्ति के लिए नीचे दिए गए विकल्पों में से सही शब्द चुनिए: