Topic 12: Genetics & Athletic Performance (HL)

Question 1

12.1.1. Outline the role of genes in the inheritance of human characteristics

Answer 1

• Children inherit genes from their parents via the sex cells (gametes), with 50% mother, 50% father.
• Human characteristics (or phenotype) are determined by their genes (the genotype).
• Some traits are solely determined by genes (e.g., eye color, gender), while others depend on both genes and environmental factors (e.g., height, VO2max).

Question 2

Genes

Answer 2

• Segments of chromosomes that direct the production of proteins
• Genes can be switched on or switched off depending on external factors

Question 3

Chromosomes

Answer 3

• Within nucleus of the cell
• Made up of long ‘wound-up’ strands of DNA (and protein)
• Genetic information of the cell
• Made up of genes
• 23 pairs (1 from each parent)

Question 4

Alleles

Answer 4

A different form of a gene that codes for a different version of a characteristic

Question 5

Genotype

Answer 5

The actual genes that a person possesses

Question 6

Phenotype

Answer 6

The physical expression of a trait as a result of genes

Question 7

12.1.2 - Outline how genes can influence human characteristics. IMPORTANT!

Answer 7

• Genes code for the production of proteins –> responsible for the development of an individual.
• Genes can be switched on or switched off depending on internal or external factors –> characteristics influencing athletic performance can change during a person’s lifetime.
• Multiple genes contribute to an individual’s heritable characteristics, making it unlikely that a single or few genetic elements are solely responsible for superior athletic performance.

Question 8

12.1.3. Discuss the relative contribution of genetic and environmental factors on performance in different sports

Answer 8

• Genetics influence traits like height, muscle fiber type, anaerobic threshold, lung capacity, and flexibility.
• Environmental factors such as physical training, nutrition, technology, and climate also affect performance.
• Training can help maximize performance within the limits set by genetics.
• Elite athletes are distinguished by inherited traits and training history.
• Genes can be turned on and off, therefore characteristics influencing performance may not be permenant.

Question 9

Genetic factors affecting performance

Answer 9

• Gender
• Ancestry & ethnicity
• Muscle fiber types
• Muscle elasticity
• Fatigue resistance
• Injury resistance

Question 10

Environmental factors affecting performance

Answer 10

• Skill level
• Age
• Sleep
• Nutrition: food + water
• Mental strength
• Confidence

Question 11

What is genetic testing or genetic screening?

Answer 11

• A medical test which identifies changes in chromosomes, genes or proteins.

The result can give information on the presence of a suspected genetic condition or help determine a person’s chance of developing/passing on a genetic disorder

Question 12

What are some common methods of genetic testing?

Answer 12

• Molecular genetic tests
• Chromosomal genetic tests
• Biochemical genetic tests

Question 13

12.1.4. Discuss the implications of genetic screening for sports, exercise and health

(Benefits of genetic screening in sports)

Answer 13

• Identify life threatening conditions such as risk of sudden cardiac death, connective tissue disorder
• Identify potential for certain sports based on genetic profile
• Potential to predict susceptibility to injury (reduce risk)

Question 14

12.1.4. Discuss the implications of genetic screening for sports, exercise and health

(Negatives of genetic screening in sports)

Answer 14

• ethical implications of involuntary exclusion from, or discrimination in, one or more sports
• ethical implications of discrimination beyond sport, for example, in employment
• the possibility of gene doping in the future to improve athletic performance.