Answer:
b. It allows gas exchange while preventing water loss
Explanation:
Amniotic eggs are the feature of land animals such as reptiles, birds, mammals, etc. The amniotic eggs have four extra-embryonic membranes. This semipermeable protective shell allows the exchange of respiratory gases but does not support the transport of water out of the egg.
The ability to maintain the water inside the egg while permitting gaseous exchange is the specific feature of amniotic eggs and allowed diversification of land animals in the land habitats.
Answer:
The hypothalamus is a brain structure that contains a number of small areas that perform a variety of functions, including the regulation of hunger and sexual behaviour, as well as linking the nervous system to the endocrine system via the pituitary gland.
The tetraspanins Tspan8 and CD151 promote metastasis, exosomes (Exo) being suggested to be important in the cross talk between tumor and host. The contribution of Tspan8 and CD151 to host versus tumor-derived exosome (TEX) activities being not defined, we approached the questions using 3-methylcholanthrene-induced (MCA) tumors from wt, Tspan8ko, CD151ko and Tspan8/CD151 (db)ko mice, implanted into tetraspanin-competent and deficient hosts.
Methods:
Tumor growth and dissemination, hematopoiesis and angiogenesis were surveyed in wild type (wt), Tspan8ko, CD151ko and dbko mice bearing tetraspanin-competent and -deficient MCA tumors. In vitro studies using tumor cells, bone marrow cells (BMC) and endothelial cells (EC) elaborated the mechanism of serum (s)Exo- and TEX-induced target modulation.
Results:
Tumors grew in autochthonous and syngeneic hosts differing in Tspan8- and/or CD151-competence. However, Tspan8ko- and/or CD151ko-tumor cell dissemination and settlement in metastatic organs was significantly reduced in the autochthonous host, and less severely in the wt-host. Impaired wt-MCA tumor dissemination in the ko-host confirmed a contribution of host- and tumor-Tspan8/-CD151 to tumor cell dissemination, delivery of sExo and TEX being severely impaired by a Tspan8ko/CD151ko.
Conclusions:
Tspan8-/CD151-TEX play central roles in tumor progression. Tspan8-/CD151-sExo and TEX contribute by stimulating angiogenesis. Tspan8 and CD151 fulfill these tasks by associating with function-relevant proteins, the additive impact of Tspan8 and CD151 relying on differences in preferred associations. The distinct Tspan8 and CD151 contributions suggest a blockade of TEX-Tspan8 and -CD151 promising for therapeutic intervention.
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The effects of aftermath of a hurricane are...destruction of electricity connections, maybe farms are affected and ofcourse human lifestyles.
Answer: Active Transport
Active and passive transport are two biological processes which are occurring all the time in the cells and body. These processes provide oxygen and other nutrients to the cells and remove waste materials from the body. But both processes differ from each other on the basis of gradient and expense of energy.
Because In active transport, nutrients move from low concentrated region to high concentrated region on the expense of energy whereas, in passive transport, nutrients move from high concentration to low concentration without the use of energy.
ACTIVE TRANSPORT, molecules move against the concentration gradient.
