3.1 Identify part A - NSC Life Sciences - Question 3 - 2022 - Paper 1

If part C is damaged, which is responsible for controlling vital processes such as heartbeat and breathing, it can lead to failure of these functions. This can result in death as the body may not be able to sustain necessary life-supporting activities.

Part B is identified as the Spinal Cord.

Damage to the spinal cord disrupts the transmission of nerve impulses from the brain to the skeletal muscles. Therefore, the signals that would normally control voluntary movements in the legs cannot reach the muscles, resulting in a lack of voluntary movement or control.

The data for Africa may not be accurate due to underreporting of severe brain injuries, often attributed to inadequate health care facilities and insufficient data collection methods in many regions.

To create a bar graph, plot the regions of the world on the x-axis and the number of severe brain injuries per 100,000 people on the y-axis. Use appropriate scales and ensure each bar is equally spaced and of equal width, representing the values accurately.

Part C of the diagram represents the Cochlea.

Part D, which is the Eustachian tube, functions to equalize pressure in the ear.

The receptors found in part C convert sound waves into electrical impulses for the auditory nerve.

A build-up of ear wax at part A can block sound waves from reaching the eardrum, leading to temporary hearing loss as the sound cannot pass through.

Grommets allow air to enter the middle ear and prevent fluid build-up, which can lead to pressure equalization. This keeps the eardrum functioning properly, thus preventing hearing loss associated with middle-ear infections.

The receptors in part B, or the vestibular apparatus, detect changes in the speed or direction of head movement. They send impulses to the brain, which processes this information and coordinates the necessary muscle adjustments to maintain balance.

The independent variable is whether the participants are wearing a facemask or not.

The dependent variable is the carbon dioxide levels in the blood.

1. The age of participants should range around 30 years.
2. Participants should be healthy individuals without respiratory conditions.

The results can be considered reliable because a controlled baseline was established, ensuring consistency in measurement across all phases.

A 15-minute interval was allowed to ensure the participants' carbon dioxide levels returned to baseline before the next measurement, minimizing any residual effect from previous activity.

Measuring carbon dioxide levels while participants were sitting still eliminates the influence of physical activity on breathing rate, providing a clear assessment of the facemask's effect.

When carbon dioxide levels are high, receptors in the carotid arteries send signals to the medulla oblongata, leading to an increase in breathing rate. This enhances the exhalation of carbon dioxide, helping to restore balance.

1. The tips of stems (apical meristem).
2. The tips of roots.

1. Auxins stimulate cell elongation, leading to an increase in stem length.
2. Auxins encourage cell division, further contributing to growth.

One other plant hormone is Gibberellins.

Auxins can enhance root development in cuttings, increasing the survival rate of propagated plants. This method helps conserve endangered plant species by facilitating their propagation and reintroduction into their natural habitats.