The right answer is vein (it contains blood and has valves).
The infra-cardiac veins of small and medium caliber possess this system of fight against gravity. The valves consist of a dense connective tissue, surmounted by endothelial cells, corresponding to a fold of the intima. They allow blood circulation in the sense organ / heart but prevent venous reflux.
Answer:
The relationship data of the dominance for each trait between the alleles was available with Mendel. The purpose of the dihybrid cross was to determine the type of relationship that existed between the pair of alleles.
The best evidence of such phenomena could be a population's genetic variation decrease.
When a population bottleneck occur it means that for some reason (i.e. environmental events) the size of a population is largely reduced. This leads to reduction of the genetic variation in that new smaller population. When a bottleneck occur, the founder effect is normally seen, which is that one population is established by a small group of a previously larger population leading once again the genetic variation, now though with a bigger population, to be very reduced.
Answer:
spiders are. generally ectotherms.Their internal temperature depends on external temperature transfer.They are also poikilothermic because the body temperature varies with that of the external environment.,
In animals, individual cells are grouped into tissues. e,g Blood. The tissues gives rise to organs.
A main function of most types of epithelial tissue is covering surfaces.They line major all hollow surfaces, and covering body surfaces.
Resorption id the movement of fluid from the glomerular filtrate back into the blood. Ions, glucose,and other escaped metabolites are returned to the blood stream.
In humans, goosebumps are a vestige of a mammalian adaptation to thermoregulation. This is a thermoregulatory mechanism to regulate the body temperature,Goosebumps emits heat, to turn the moisture from the skin to vapour. This evaporate to release this moisture, which cools the body.
Explanation:
