Biology MCQs
Topic Notes: Biology
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
1
Regarding stem cells, which of the following statements are correct? 1. Derived from mammals only. 2. Used for drug screening. 3. Used for medical therapies.
Answer:
Only 2 and 3
Stem cells are undifferentiated cells capable of self-renewal and differentiation into specialized cell types. They are found in many multicellular organisms, not just mammals. They are widely used in pharmaceutical research for screening new drugs for efficacy and toxicity, and in regenerative medicine to develop therapies for various diseases and tissue injuries.
2
Which animal was the first in the world to be successfully cloned under the name 'Injaz'?
Answer:
camel
Injaz was the world's first cloned camel, born in Dubai in 2009. The project was a significant scientific achievement in the field of reproductive biotechnology, demonstrating that somatic cell nuclear transfer techniques could be successfully applied to dromedary camels, which are culturally and economically important in the Middle East.
3
Which of the following statements accurately describes a clone of an organism?
Answer:
A clone is produced asexually
A clone is a genetically identical copy of an organism. Cloning is inherently an asexual process because it involves the replication of genetic material without the fusion of gametes (sperm and egg) from two different parents, which would otherwise introduce genetic recombination and variation.
4
Which type of cells are characterized by their ability to divide and differentiate into various specialized cell types, making them a primary focus for regenerative medicine?
Answer:
Stem cells
Stem cells are unique biological cells that possess the capacity for self-renewal and the ability to differentiate into a wide range of specialized cell types. Because of these properties, they are extensively researched for their potential to treat degenerative diseases, repair damaged tissues, and provide insights into human development and disease progression.
5
For what specific purpose is human cloning legally permitted in the United Kingdom?
Answer:
therapeutics
In the UK, therapeutic cloning (also known as somatic cell nuclear transfer for research) is permitted under strict regulatory oversight. This process involves creating cloned embryos to harvest stem cells for medical research, rather than for reproductive purposes. The goal is to develop treatments for degenerative diseases by creating patient-specific stem cell lines.
6
Which biological technique was utilized to successfully create the cloned sheep known as 'Dolly'?
Answer:
Nuclear transfer
Dolly the sheep was produced using somatic cell nuclear transfer (SCNT). In this process, the nucleus of a somatic cell from an adult donor is transferred into an enucleated oocyte (egg cell). The resulting embryo is then implanted into a surrogate mother. This technique demonstrates that the nucleus of a specialized adult cell retains the genetic potential to form an entire organism.
7
Which undifferentiated cells possess the potential to develop into various specialized cell types, making them essential for regenerative medicine and tissue engineering?
Answer:
Stem cells
Stem cells are unique biological cells that can differentiate into specialized cell types. Because they can self-renew and differentiate into various tissues, they are often referred to as the building blocks or 'spare parts' for regenerative medicine, allowing scientists to potentially repair or replace damaged human tissues and organs.
8
What is the fundamental mechanism of gene therapy when addressing a faulty gene?
Answer:
Another good gene is inserted
Gene therapy primarily functions by introducing a functional copy of a gene into the patient's cells to compensate for the defective or missing gene. While the goal is to restore normal function, the standard approach involves the insertion of a healthy gene rather than the physical removal or replacement of the original genomic sequence.
9
Which of the following is commonly referred to as 'cruelty-free meat' due to its production method?
Answer:
In vitro meat
In vitro meat, also known as cultured meat or lab-grown meat, is produced by culturing animal cells in a laboratory setting rather than raising and slaughtering animals. Because it does not require the death of an animal, it is frequently marketed and referred to as cruelty-free meat.
10
Identify the incorrect statement regarding Dolly the sheep, the first mammal successfully cloned from an adult somatic cell.
Answer:
Dolly was born in the year 1998
Dolly the sheep was born on July 5, 1996, at the Roslin Institute in Scotland, not 1998. She lived until 2003 and suffered from progressive lung disease, which is common in older sheep. Her birth was a landmark event in science, proving that a specialized adult cell could be reprogrammed to create a new, genetically identical individual.