Research Using Twins: IELTS Reading Passage with Questions & Answers

Introduction:

Twin studies have long fascinated researchers, offering a unique lens through which to understand the complex interplay between genetics and environment. This IELTS reading passage delves into how twins have contributed to scientific knowledge, enabling learners to practice their comprehension skills through a series of questions.

Passage:

Research utilizing twins has been instrumental in unraveling the mysteries of human genetics and behavior. Identical twins, or monozygotic twins, are natural clones, having split from the same fertilized egg. They share nearly all their DNA. Fraternal twins, or dizygotic twins, are no more genetically similar than regular siblings, sharing only about 50% of their DNA. This genetic distinction is pivotal for studies aiming to dissect the contributions of heredity and environment.

Twins provide a unique opportunity to explore the effects of different environments on individuals with the same genetic makeup. For instance, if one identical twin develops a condition that the other does not, researchers can reasonably infer that the condition may be influenced more by environmental factors than genetics.

In the realm of behavioral science, twin studies have shed light on the 'nature versus nurture' debate. By comparing the similarities and differences of identical twins raised apart with those raised together, scientists gain insights into how much a trait is influenced by genetics versus environment.

The Minnesota Twin Study is one of the most notable twin studies, which followed a cohort of separated twins over 20 years. The findings revealed striking similarities in personality, interests, and habits between twins, even when they had been raised in completely different family settings.

However, twin studies are not without limitations. Critics argue that the environments of twins, even when raised apart, are not entirely dissimilar, as they often share similar socio-economic statuses or cultural backgrounds. Furthermore, the unique bond between twins may lead to shared experiences that can skew results.

Despite these challenges, twin research continues to be a valuable asset in understanding human development. It paves the way for questions about the balance of predetermined genetics and the shaping hand of our environments.

Questions & Answers:

Q1: What are identical twins also known as?

A. Fraternal twins

B. Monozygotic twins

C. Dizygotic twins

D. Non-identical twins

A1: B. Monozygotic twins

Explanation: Identical twins are referred to as monozygotic because they originate from a single (mono) fertilized egg that splits (zygote).

Q2: Fill in the blank: Fraternal twins share about ______% of their DNA.

A. 25

B. 50

C. 75

D. 100

A2: B. 50

Explanation: Fraternal twins are dizygotic, meaning they come from two separate eggs and sperm, making them genetically similar to regular siblings with a 50% DNA overlap.

Q3: True or False: The Minnesota Twin Study lasted for 10 years.

A. True

B. False

A3: B. False

Explanation: The Minnesota Twin Study lasted over 20 years, not 10, making it one of the most extensive and informative twin studies in the realm of behavioral science.

Q4: What can be inferred if one identical twin develops a condition that the other does not?

A. The condition is entirely genetic.

B. The condition is due to the environment.

C. Twins do not share any similarities.

D. The condition is neither genetic nor environmental.

A4: B. The condition is due to the environment.

Explanation: Since identical twins share almost all their DNA, differences in conditions suggest environmental rather than genetic influences.

Q5: Fill in the blank: Twin studies have helped in understanding the '________ versus nurture' debate.

A. Nature

B. Nurture

C. Culture

D. Structure

A5: A. Nature

Explanation: Twin studies are essential for dissecting the 'nature versus nurture' debate, which looks into the relative contributions of genetic inheritance and environmental factors to human development.

Q6: How much DNA do identical twins share?

A. About 25%

B. About 50%

C. Nearly 100%

D. None of the above

A6: C. Nearly 100%

Explanation: Identical twins, or monozygotic twins, originate from a single fertilized egg that splits, meaning they share nearly all of their DNA, which is as close to 100% as possible for any two individuals.

Q7: Fill in the blank: Critics of twin studies argue that the environments of twins are not entirely dissimilar due to often shared _______ statuses or cultural backgrounds.

A. Socio-economic

B. Genetic

C. Educational

D. Environmental

A7: A. Socio-economic

Explanation: Critics point out that even when raised apart, twins may still experience similar environments in terms of socio-economic status and cultural backgrounds, which can influence the outcomes of the studies.

Q8: True or False: Twin studies have conclusively resolved the nature versus nurture debate.

A. True

B. False

A8: B. False

Explanation: While twin studies have provided significant insights into the nature versus nurture debate, they have not conclusively resolved it. This debate remains ongoing as both elements play complex and interactive roles in human development.

Q9: What does the 'unique bond' between twins potentially affect in twin studies?

A. The genetic makeup

B. The accuracy of the studies

C. The environmental impact

D. The development of twins

A9: B. The accuracy of the studies

Explanation: The unique bond between twins may lead to shared experiences and interactions that can influence the results of the studies, potentially affecting their accuracy.

Q10: Multiple-choice: The Minnesota Twin Study contributed to our understanding of which of the following?

A. Genetic similarities in twins

B. Personality and habits

C. Only physical characteristics

D. Only intellectual abilities

A10: B. Personality and habits

Explanation: The Minnesota Twin Study followed separated twins over 20 years and found striking similarities in personality, interests, and habits between twins, even when raised apart, thereby contributing significantly to our understanding of these aspects beyond just physical or intellectual traits.

Tips for Cracking the IELTS Reading Exam:

Tip 1: Always read the passage thoroughly before attempting the questions. This ensures you understand the context and can identify where the answers may be located.

Tip 2: For multiple-choice questions, eliminate options that you are certain are incorrect to improve your chances of choosing the right answer.

Tip 3: Pay attention to details that may seem minor but could be crucial for fill-in-the-blank questions.

Tip 4: Understand the difference between 'true', 'false', and 'not given' in the IELTS reading context. 'True' means the statement agrees with the information, 'false' means it contradicts the information, and 'not given' means there is no information on this.

Tip 5: Practice skimming and scanning techniques to locate information quickly and manage your time effectively during the exam.