Edexcel Biology Unit Essay Example

allowing RNA polymerase to initiate transcription. New anti-cancer therapies must pass animal testing and undergo independent review before entering 3-stage clinical trials that involve erect descriptions of double-blind, placebo, and randomization procedures. Pain receptor impulses from rodents are transmitted via sensory neurons to the central nervous system.The propagation of neural impulses can be compared to a wave of deportations, where an influx of sodium ions into a neuron allows for local currents to facilitate propagation, known as salutatory conduction.

To withdraw a hand from a hot stove, sensory neurons send signals to relay neurons and then motor neurons via synapses.

Breathing air with 5% carbon dioxide would result in an increase in ventilation rate due to receptors in the aortic/carotid body and medulla detecting a rise in CO2/fall in pH, triggering more impulses from the ventilation centre to intercessor muscles such as the diaphragm.

Oxygen plays a crucial role in the production of TAP/energy as it acts as the final acceptor of hydrogen at the end of the electron transfer chain, allowing for the continuation of the proton gradient/chemisorbs. Without oxygen, the Krebs cycle and electron transport would cease, leading to a brain deprived of TAP/energy.

Naked mole rats have evolved to be resistant to hypoxia due to living in a low oxygen environment being a selection pressure. Genetic variability exists in the population, with alleles for withstanding hypoxia increasing due to mutation.

Modern scanning techniques have revolutionized our understanding of the localization of function in the brain. Females do not play a specific role in this transformation.The use of MR imaging allows for the study of brain function and comparison to early techniques such as injury studies, animal experimentation

with electrode insertion, and drug effects. This non-invasive method follows oxygen uptake in active brain areas, allowing researchers to identify regions involved in specific tasks. The new prosthetics being developed at CUL are less likely to damage tissues because they are bonded to bone, rather than pressing on soft tissue. However, there is a risk of infection entering the body between the prosthetic and skin. The queen alters the hormonal balance of non-breeders to prevent them from becoming reproductive. This type of communication differs from nervous communication, as hormonal communication is slower acting, has a longer duration of response, affects all cells with receptors, and controls long-term changes like growth. To produce a DNA fingerprint from a Naked Mole Rat, DNA must be extracted from cells and a gene isolated with restriction enzymes. Amplification using PCR and electrophoresis would be utilized in the process.The technique of electrophoresis reveals that small DNA fragments move faster through gels when subjected to an electric field. This is important in Southern blotting, where a probe is used to visualize DNA. To increase the long-term survival of Naked Mole Rat populations, out-breeding is recommended because it increases genetic variation and prevents inbreeding depression. In suppressing breeding in non-breeding males, the stimulus is the behavioral interaction with the queen, the effecter is the testis, and the response is lowered testosterone and production of fewer non-motile sperm. From a utilitarian viewpoint, some experiments on Naked Mole Rats can be justified because suffering is limited to a few individuals, and their reduced sensitivity to chemical pain implies a lower capacity to suffer. Furthermore, research on these animals has significant potential benefits for human

health.