Q621. If a pea plant with round seeds (RR) is crossed with a plant with wrinkled seeds (rr), what will be the genotype of the F1 generation?
Science and Technology: RAS Prelims MCQs
1113 RAS Prelims practice MCQs on science and technology are on this page, in 6 chapters. They cover the basics of everyday science, computers and information technology, defence and space technology in India, genetics, biotechnology and nanotechnology, science and technology policies and government programmes, and recent advances with Indian contributors and indigenisation. Each question has an answer and an explanation.
Practice questions based on the RPSC RAS Prelims syllabus. They follow the exam pattern but are not past-paper questions.
Showing 621–630 of 1113 questions
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Q622. Which trait among the following was not studied by Gregor Mendel in pea plants?
Explanation
Gregor Mendel focused his genetic research on seven specific, easily observable traits in the garden pea plant. These included seed shape, seed color, flower color, pod shape, pod color, flower position, and stem height. Root length was not among the characteristics he systematically studied. His careful selection of these clear, binary traits allowed him to derive the fundamental laws of heredity.
Q623. Chromosomes that are not involved in sex determination are called:
Explanation
Autosomes are the chromosomes in an organism that are not involved in determining the sex of an individual. In humans, there are twenty-two pairs of autosomes. These chromosomes carry the majority of the genetic information responsible for general bodily functions and physical characteristics. This distinguishes them from the sex chromosomes, or allosomes, which specifically determine the biological sex of the offspring.
Q624. In the normal human karyotype, how many pairs of autosomes are present?
Explanation
A normal human karyotype consists of twenty-three pairs of chromosomes, totaling forty-six in each somatic cell. Out of these, twenty-two pairs are classified as autosomes. These pairs are homologous and contain genes for traits unrelated to sex determination. The remaining twenty-third pair consists of the sex chromosomes, which are XX in females and XY in males, completing the full genetic complement.
Q625. The highly condensed and transcriptionally inactive region of a chromosome is called:
Explanation
Heterochromatin refers to regions of the chromosome that remain highly condensed and tightly packed throughout the cell cycle. Due to this dense structure, these areas are generally transcriptionally inactive, meaning the genes within them are not expressed. This contrasts with euchromatin, which is less condensed and contains actively transcribed genes. Heterochromatin plays a vital role in maintaining chromosome structural integrity and gene regulation.
Q626. Match List-I with List-II regarding chromosome types:
| Chromosome type | Centromere position |
|---|---|
| A. Metacentric | i. Centromere at the terminal end |
| B. Sub-metacentric | ii. Centromere in the middle, equal arms |
| C. Acrocentric | iii. Centromere close to the end |
| D. Telocentric | iv. Centromere slightly away from the middle |
Explanation
A metacentric chromosome has its centromere in the middle, a sub-metacentric slightly away from the middle, an acrocentric close to one end and a telocentric at the terminal end. This gives A-ii, B-iv, C-iii, D-i.
Q627. Consider the following statements about human chromosomes:
I. The Y chromosome is smaller than the X chromosome.
II. Telomeres protect the ends of chromosomes from deterioration.
III. Kinetochores form at the centromere during cell division.
IV. A normal human female karyotype is 46, XY.
V. Histone proteins help package DNA into chromosomes.
Which of the above statements is incorrect?
I. The Y chromosome is smaller than the X chromosome.
II. Telomeres protect the ends of chromosomes from deterioration.
III. Kinetochores form at the centromere during cell division.
IV. A normal human female karyotype is 46, XY.
V. Histone proteins help package DNA into chromosomes.
Which of the above statements is incorrect?
Explanation
In human genetics, a normal female karyotype is designated as forty-six, XX, while a male is forty-six, XY. The Y chromosome is physically smaller than the X. Telomeres provide essential protection at chromosomal ends, and kinetochores are necessary for spindle attachment. Histone proteins facilitate DNA packaging. Therefore, identifying a female as having an XY configuration is factually incorrect.
Q628. What is the primary function of telomeres?
Explanation
Telomeres are repetitive nucleotide sequences located at the extreme ends of linear chromosomes. Their primary role is to protect the ends of the DNA from deterioration or fusion with neighboring chromosomes. Because DNA polymerase cannot fully replicate the very tips of chromosomes, telomeres act as a buffer, ensuring that essential genetic information is not lost during successive rounds of cellular division and replication.
Q629. Which of the following chromosomal arrangements represents the karyotype of a normal human male?
Explanation
The karyotype of a normal human male consists of forty-six chromosomes in total. This includes twenty-two pairs of autosomes, which equals forty-four autosomes, and one pair of sex chromosomes consisting of one X and one Y chromosome. This chromosomal arrangement distinguishes males from females, who possess two X chromosomes alongside the forty-four autosomes. This genetic configuration is established at the moment of fertilization.
Q630. Which of the following represents the odd one out regarding chromosome structural components?
Explanation
Centromeres, chromatids, and telomeres are all integral structural components of eukaryotic chromosomes found within the cell nucleus. In contrast, a plasmid is a small, circular, extra-chromosomal DNA molecule found primarily in bacteria. Plasmids replicate independently of the main bacterial chromosome and are not part of the standard structural anatomy of the linear chromosomes found in higher eukaryotic organisms like humans.Answer key for these questions
| Q | Correct answer |
|---|---|
| 621 | (b) Rr |
| 622 | (d) Root length |
| 623 | (a) Autosomes |
| 624 | (a) 22 pairs |
| 625 | (b) Heterochromatin |
| 626 | (a) A-ii, B-iv, C-iii, D-i |
| 627 | (b) IV only |
| 628 | (d) Maintenance of genomic stability during DNA replication |
| 629 | (b) 44 Autosomes + XY |
| 630 | (c) Plasmid |
Key facts from Science and Technology
- The RPSC paper is General Knowledge and General Science, so science questions come with a strong dose of applied and recent topics.
- Everyday science questions test the laws and terms of physics, chemistry and biology through examples.
- Defence and space questions pair a missile, satellite or mission with its year and organisation.
- Policy questions ask for the year, the body and the aim of schemes like STIP, the National Quantum Mission and BioE3.
- Health, environment and agriculture are on a separate page, with their own chapters.
Frequently asked questions
How many RAS Prelims practice MCQs are there on Science and Technology?
This page has 1113 practice MCQs on Science and Technology. Each has the correct answer, and most have an explanation.
Which chapters does the science and technology set cover?
Six chapters: basics of everyday science; computers, information and communication technology; defence and space technology in India; genetics, biotechnology and nanotechnology; science and technology policies and government programmes; and recent advances, Indian contributors and indigenisation.
Is science and technology part of the RAS Prelims syllabus?
Yes. The RPSC paper is called General Knowledge and General Science, and its syllabus lists science and technology topics along with environment, health, agriculture and government programmes, so questions can come from any of these areas.
How should I prepare science for RAS Prelims?
Revise the concepts by examples, then learn the missions, schemes and scientists with their year and organisation. Attempt each chapter, read the explanations and keep a list of the facts you missed.