Indicator species may provide useful substitute for large scale surveys to monitor biodiversity. Weconducted surveys in the Afro-alpine habitats of the Bale Mountains National Park (BMNP) with theobjective of identifying indicators for the species richness of the raptor guild. Raptors were countedby scan sampling technique from a suitable vintage point. Three classes of 18 sample units groupedaccording to the variability of the moorland ecosystem in the magnitude of process variables importantfor raptor species richness were used in determining the indicator value of species as a function of their abundance concentration and the percentage of species occurrence per sample group. Thisprocedure determined indicator values for all species in the resident raptor community. Comparisonwith randomly expected values demonstrated that only<span> Aquila verreauxii</span>and<span> A. chrysaetos</span>haveindicator values that were significantly larger than the randomly expected values. The species richnessestimated using the abundances of these two species predicted the observed species richness of thewhole community in a linear regression model that explained 66% of the deviance in the data set.Furthermore, the species richness of the community predicted by process variables had correlation of very high significance with that predicted by the indicator species. We have thus identified twoindicator species to a raptor guild of the BMNP and demonstrated that these two species encapsulatedmost of the information regarding the species richness response of the guild to key process variablesin the Afro-alpine moorland ecosystem. Our findings contribute significantly to current and futureefforts of monitoring the biodiversity of the park providing a cheap and quick means of data generation<span>relevant for making management decisions. Hope this helped! :)</span>
Answer:
4) It allows the exchange of nutrients between the embryo and the mother, while at the same time filtering out harmful material.
Explanation:
The placenta is an organ present in all mammals. She is confirmed between the 6th and 8th week of pregnancy and has as main function the exchange of substances between the mother and the fetus. Among these substances are nutrients, gases and even secretions. The placenta also has the function of fighting infections and promoting immunity to the fetus, in addition, it can act as the lung, the intestine and the liver, while the fetus does not develop its organs.
