<span>Oxygen travels to insect tissues through tiny openings in the body walls called spiracles, and then through tiny blind-ended, air-filled tubes called tracheae. Therefore, insects obtain oxygen through the spracles, which are small abdominal holes that lead into traecheal tubes called tracheae that branch into smaller tubes called tracheoles. From there, oxygen diffuses into body cells.</span>
By definition, the phenotype is the actual physical manifestation of an organism's genotype, so the way an organism looks or behaves is what is being selected on. For example, if ladybugs have red (R) shells or yellow (r) shells and ladybug-eating birds only eat the ones with red shells, any red-shelled ladybugs will be selected against based only on their phenotype. The birds do not know whether each bug is RR, Rr, of rr, so phenotype, not genotype, is what is affected by natural selection.
The correct option is A.
Post parturient refers to the period after a living organism have given birth to offspring. Post parturient ketosis is a type of ketosis that occur to a female animal after she has given birth to young ones. Glucose is the major fuel that living organisms used to generate energy, when there is shortage of glucose, the body use fat instead as fuel and this leads to the production and build up of ketone bodies. The build up of ketone bodies increases the level of ketones in the blood and this state of metabolismis called ketosis.
