<span>Ian Waterman was able to sense pain and temperature because his
spinothalamic pathway was intact, but could not feel touch and limb position because of damage to his
lemniscus pathway. </span>
The lateral spinothalamic tract is a sensory pathway which carries sensory information like pain and temperature to the brain, across the thalamus. Free nerve endings which are located in the peripheral tissues are sensitive to cell damage. Those are primary neurons and they pass the sensory signal. Primary neurons synapse with secondary which are located in the spinal cord (white matter). These secondary neurons will ascend through the brainstem, medulla oblongata, pons and midbrain, until synapsing in the ventroposteriorlateral (VPL) nucleus of the thalamus. From the thalamus, the information is sent to cortex (somatosensory cortex).
Posterior column-medial lemniscus pathway is ascending spinal tract, carrying sensory information to the brain (sensory pathway). It conducts localized sensations of fine touch, vibration and proprioception (position sense) from the skin and extremities (muscles) to the central nervous system (cerebral cortex).
Answer:
The correct selection of answers to the question: Identify the pieces of evidence describing the features of DNA that Watson and Crick used to determine the structure of DNA, would be:
C: The two chains are parallel, both running in a 5´ to 3´ direction
D: A purine base forms hydrogen bonds to pair with a pyrimidine base located on the opposite DNA strand. Specifically, A pairs with T, and C pairs with G.
E: The sugar-phosphate backbones of each DNA helix run antiparallel to one another
F: The diameter of the DNA doube helix is 2 nm, with each purine-pyrimidine base pair spanning an equivalent distance between the two chains.
Explanation:
Although Watson´s and Crick´s research, and model of the DNA helix, became the breakthrough for science, as it visually presented the now known characteristics of DNA, this research was possible due to the way that these two researchers used previous information found by other scientist on the molecule, to finally build their model. All of the options that were selected were part of the research of several scientis, including Mendel, Rosalin Franklin, Linus Pauling, Maurice Wilkins, Oswald Avery and many others, who worked on different aspects of specimens and their specific characteristics, and which led them to discover that organisms possessed DNA, that this was the unit of information that directed all functions in living cells and how this DNA helix was chemically built to understand how it worked, and why it worked the way it did.
Answer:
The correct answer will be option-A
Explanation:
Colchicine is the drug that prevents the assembly of the mitotic spindles which halts or stops the cell cycle.
The colchicine acts by inhibiting the microtubule polymerization thus mitotic spindles which takes place after the condensation of the chromosomes during prophase and pre-metaphase.
This acts as checkpoint which can halt the cell cycle at the phase of chromosome condensation.
Thus, option-A is the correct answer.
Answer:
Four haploid gametes are formed
Explanation:
