Unit 12

Question 1

How many chromosomes are there in a human cell

Answer 1

46

Question 2

Chromosomes are made of a thread of what?

Answer 2

DNA

Question 3

What is the function of DNA

Answer 3

carries the genetic instructions used in the growth, development, functioning and reproduction of living things

Question 4

What is the role of Outline the role of genes in the inheritance of human characteristic

Answer 4

Children inherit genes from their parents via the sex cells (gametes), with 50% from the mother and 50% from the father
- Human characteristics (or phenotype) are determined by their genes (the genotype)
- Some characteristics are expressed developmentally by genes (ex. eye colour), others require an environmental switch (ex. height, VO₂ max)

Genes control the characteristics that an offspring will have by transmitting information in the sequence of nucleotides.​

Question 5

Outline how genes can influence human characteristics

Answer 5

• Genes code the production of proteins which are responsible for the development of
  an individual
• They can be switched on or off depending on internal or external factors
  ↳ certain characteristics can change during a person’s lifetime
• Genes determine the heritable characteristics for each individual
• Genes expressed as phenotypes

Question 6

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

Answer 6

Factors that are influenced by genetics:
- Height
- Muscle fiber type
- Anaerobic threshold
- Lung capacity
- Flexibility

Environmental Factors:
- Physical training
- Nutrition
- Technological aids
- Climate

Training maximizes the likelihood of
obtaining a performance level with a
genetically controlled ceiling
Elite athletes can be distinguished from less well-performing athletes with respect to both inherited (Genetic) characteristics and
training histories.

It is presently not possible to ascertain the relative contribution of genetics or training to elite sporting performance, and this contribution is likely to differ for different sports

Question 7

Discuss the advantages and disadvantages of genetic
screening for sports, exercise and
health

Answer 7

Advantages
- identification of life-threatening
conditions such as the risk of sudden
cardiac death
- you can be given genes that your parents don’t have
- potential to predict susceptibility to injury and so reduce risk/improve safety for an individual athlete

Disadvantages:
- it is expensive and can cause inequality in society (only available to the rich)
- can be considered unethical or unfair (possible gene doping)
- can damage the overall gene pool