Free Plant Breeding and Genetics MCQs with Answers
329 Plant Breeding and Genetics MCQs from Agriculture, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
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329 questions · page 8 of 17
- A. Disintegrates partially
- B. Disappears completely
- C. Contracts
- D. Becomes vacuolated
Explanation: As a plant cell matures, its vacuole enlarges and the cytoplasm is pushed toward the periphery, becoming vacuolated.
Correct answer: Becomes vacuolated- A. Watson and Crick
- B. Tatum
- C. Koran
- D. Dtanele
Explanation: Watson and Crick proposed the double-helical model of DNA in 1953, using evidence including Chargaff’s rules and X-ray diffraction…
Correct answer: Watson and Crick- A. Van Mohl
- B. Miescher
- C. Benda
- D. Schultz
Explanation: Friedrich Miescher isolated the acidic substance now known as nucleic acid from cell nuclei in 1869.
Correct answer: Miescher- A. DNA
- B. RNA
- C. DNA & RNA
- D. DNQA and protein
Explanation: Nucleic acids are the two major genetic polymers, DNA and RNA, both made of nucleotide units.
Correct answer: DNA & RNA- A. Lysosomes
- B. Ribosomes
- C. Lysozymes
- D. Dictysomes
Explanation: Lysosomes contain hydrolytic enzymes that digest cellular waste, foreign particles and worn-out organelles, so they are often called…
Correct answer: Lysosomes- A. Any two members of a Genus
- B. Any two members of a Species
- C. Any two members of a Family
- D. Any two members of an order
Explanation: Interbreeding is generally possible among members of the same species because they share sufficiently compatible genetic systems and can…
Correct answer: Any two members of a Species- A. 25%
- B. 75%
- C. 50%
- D. 40$
Explanation: If the dominant phenotype is 75%, the recessive phenotype is 25%, so under Hardy-Weinberg equilibrium q² = 0.25, giving q = 0.5 and p =…
Correct answer: 50%- A. TT and Tt only
- B. TT and tt only
- C. Tt and Tt only
- D. TT Tt and tt
Explanation: A 3:1 tall-to-short ratio indicates a cross between two heterozygotes, Tt × Tt. Its offspring can therefore contain TT, Tt and tt genotypes.
Correct answer: TT Tt and tt- A. Ribosome's
- B. Microtubules
- C. Episodes
- D. Mitochondria
Explanation: Ribosomes are the cellular structures that translate messenger RNA into polypeptide chains, so they directly carry out protein synthesis.
Correct answer: Ribosome's- A. Hypoploid
- B. Hyperploid
- C. Allopolyploid
- D. Autopolyploid
Explanation: Hyperploid describes a chromosome number above the normal euploid or exact multiple of the basic chromosome number.
Correct answer: Hyperploid- A. Allopolyploid
- B. Amphidiploids
- C. End polyploidy
- D. Aneupoidy
Explanation: Endopolyploidy occurs when chromosomes replicate without normal cell division, producing somatic cells with multiples of the diploid…
Correct answer: End polyploidy- A. None of the aboveDownload Nature Guides
- B. Genetic drift
- C. Gene frequency
- D. Gene flow
Explanation: Gene flow is the movement of alleles between populations through migration and subsequent reproduction, which can alter allele…
Correct answer: Gene flow- A. TTxTT
- B. Ttxtt
- C. TtxTt
- D. TTxTt
Explanation: A test cross mates an individual showing the dominant trait with a homozygous recessive, such as Tt × tt.
Correct answer: Ttxtt154. In crop improvement programmed haploids are of great importance because they__________________?
- A. Are useful in studies on meiosis
- B. Grow better under adverse conditions
- C. Give homozygous lines following diplodization
- D. Require only about half the amount of chemical fertilizers compared to diploids
Explanation: Haploids contain one chromosome set, so chromosome doubling produces completely homozygous diploid lines in a single generation.
Correct answer: Give homozygous lines following diplodization- A. All the heterozygous tall
- B. All homozygous dwarf
- C. 2 tall: 2 dwarf
- D. One homozygous tall, one homozygous dwarf, two heterozygous tall
Explanation: Crossing homozygous tall TT with homozygous dwarf tt gives only Tt offspring. Since T is dominant, all offspring are heterozygous tall.
Correct answer: All the heterozygous tall156. The new crop critical has been evolved by intervener hybridization between________________________?
- A. Wheat & rice
- B. Rye & Wheat
- C. Wheat & Anglos
- D. Rice & maize
Explanation: Triticale is the crop created by combining wheat and rye through intergeneric hybridization, followed by chromosome doubling to restore…
Correct answer: Rye & Wheat- A. Pod color
- B. Pod shape
- C. Plant height
- D. Leaf shapeSearch Public Records
Explanation: Mendel's seven pea traits included pod colour, pod shape and plant height, but not leaf shape.
Correct answer: Leaf shapeSearch Public Records- A. 48
- B. 41
- C. 44
- D. 46
Explanation: Humans normally have 46 chromosomes in somatic cells, arranged in 23 pairs. Gametes contain the reduced number of 23 chromosomes.
Correct answer: 46- A. 1:1:1:1
- B. 9:3:3:1
- C. 3:1
- D. 27:9:9:3:3:3:1
Explanation: A typical Mendelian dihybrid cross involving two independently assorting genes gives the F2 phenotypic ratio 9:3:3:1.
Correct answer: 9:3:3:1- A. Chromatids become chromosomes
- B. Nuclear division come to close
- C. Exchange of chromosomal materialOrder DNA Kits
- D. Chromosomes become half in number
Explanation: Crossing over exchanges corresponding segments of DNA between non-sister chromatids of homologous chromosomes during prophase I of…
Correct answer: Exchange of chromosomal materialOrder DNA Kits