Being overweight can affect the health and life expectancy of a person - AQA - GCSE Biology Combined Science - Question 3 - 2020 - Paper 1

To find the height, we use the BMI formula.

Given:

• BMI = 27
• Body mass = 68.1 kg

We can rearrange the formula to solve for height:

$\text{height} = \sqrt{\frac{\text{body mass}}{\text{BMI}}}$

Substituting the known values:

$\text{height} = \sqrt{\frac{68.1}{27}} = \sqrt{2.5259} ≈ 1.59 \, \text{m}$

The woman falls into the 'Overweight' category as per the BMI calculation.

To maintain a healthy body mass, there should be a balance between the energy intake from food and the energy expenditure through exercise.

1. Energy Intake: If a person consumes more calories than they expend, they will gain weight. Conversely, if they eat less than they burn, they will lose weight.

2. Energy Expenditure: Exercise increases the total calories burned. Engaging in physical activities accelerates metabolism, which helps in utilizing the energy stored in the body.

3. Healthy Balance: Therefore, a manageable diet combined with regular exercise is crucial in controlling body mass effectively.

During vigorous exercise:

1. Increased Breathing Rate: The breathing rate increases to supply more oxygen.
2. Elevated Heart Rate: The heart pumps faster to circulate blood that carries oxygen to the muscles.
3. Enhanced Blood Flow: More blood flows to the muscles, aiding in oxygen delivery and nutrient supply.
4. Anaerobic Respiration: If the intensity is too high, the body may switch to anaerobic respiration, which can lead to lactic acid build-up.

After vigorous exercise:

1. Recovery: The heart rate and breathing gradually return to normal.
2. Oxygen Debt: Additional oxygen is needed post-exercise to metabolize lactic acid and restore energy levels.
3. Replenishing Resources: The body continues to consume oxygen at a higher rate after the workout to convert lactic acid back into glucose.