Vertebrae/Backbones I think.
Answer:
a. different shape (e.g. flat or ribbon shaped).
d. larger internal surface area of the lungs.
Explanation:
Amphibians are cold blooded animals. They have a low rate of metabolism . Amphibians are located most where there is water or in moist environment because of their skin and how important it is to keep their skin moist.
Amphibians breathe through their skin and this can be called cutaneous respiration. Their lungs are not well developed therefore they undergo a very slow diffusion of oxygen through their blood.
For Amphibians that are larger than bull frogs, they obtain a very sufficient rate of diffusion of gases due to the following reasons:
a. Internal surface area of the lungs: Amphibians that are larger than bull frogs tend to have a more developed respiratory organs which means there lungs have a larger surface area and they are well developed.
b. They have a different body shape: Amphibians larger than bull frogs could have a flat or ribbon shape and their body shapes make it easier for respiratory gases like oxygen to permeate or enter their skin easily.
The correct answer is C.
The egg sinks in freshwater because it is more dense than the water. So, to make the egg float, you would have to increase the density of the water. Since salt water has a greater density than freshwater, you would add salt to the freshwater, thus causing the egg to float rather than sink.
Answer:
The perception of pain throughout the body arises when neural signals originating from the terminals of nociceptors are propagated to second-order neurons in the spinal cord or brainstem, whereupon they are transmitted to specific higher-order brain areas (Price, 2000). Recent studies have begun to elucidate some of the molecular mechanisms underlying the transduction of noxious stimuli. Many stimuli have been found to activate ion channels present on nociceptor terminals that act as molecular transducers to depolarize these neurons, thereby setting off nociceptive impulses along the pain pathways (Price, 2000; Costigan and Woolf, 2000). Among these ion channels are the members of the transient receptor potential (TRP) family. To date, the most studied member of the TRP family is the TRPV1 receptor. This is because it is the only one activated by capsaicin, the compound in chili pepper responsible for its “hot” taste; also, inhibiting TRPV1 has been shown to have therapeutic value (DiMarzo et al., 2002; Cortright and Szallasi, 2004). Although we will focus on the presence of these channels in nociceptors, we note that they have been identified in many other cell types and in various cortical and subcortical areas (Toth et al., 2005). The transient receptor potential vanilloid 1 (TRPV1) channel is predicted to have six transmembrane domains and a short, pore-forming hydrophobic stretch between the fifth and sixth transmembrane domains (see Figure 5.1A). It is activated not only by the vanilloid capsaicin (Caterina et al., 1997), but also by noxious heat (>43°C) and low pH (Caterina et al., 1997; Tominaga et al., 1998), voltage (Gunthorpe et al., 2000; Piper et al., 1999), and various lipids (Julius and Basbaum, 2001; Caterina and Julius, 2001; Clapham, 2003; Cortright and Szallasi, 2004, Szallasi and Blumberg, 1999; Prescott and Julius, 2003; Jung et al., 2004; Bhave et al., 2003). In cells, TRPV1 is inactivated by its binding to PIP2 and is released from this block by PLC-mediated PIP2 hydrolysis (Prescott and Julius, 2003). TRPV1 is widely expressed in central nervous system (CNS) tissue and highly expressed in sensory neurons of the dorsal root ganglion [19]. This receptor also localizes to neurons that line the oral and nasal cavities [10], where it is found in a subpopulation of sensory afferent nociceptive nerve fibers [20].
(this is for question 1.)
Explanation:
