The symptom and sign which indicate placenta previa here is Pinless vaginal bleeding.
Placenta previa is a condition where the placenta is covering the cervix or it is attached close to the cervix.
In various times of pregnancy, bleeding may occur. It can not be a serious complication. The cause of the bleeding may depend on the amount of pain or the time of bleeding in pregnancy.
In the first trimester, bleeding may occur and may be due to ectopic pregnancy, miscarriage, implantation of the placenta in the uterus or infection.
Bleeding in late pregnancy lets say twenty weeks can be due to placenta previa or placental abruption.
Parasites benefit their hosts is the true statement. Parasitism is a symbiotic relationship in which one organism (the parasite) benefits from another organism and this other organism is harmed by the parasite.
The others aren't true because:
- the organism that is harmed doesn'y adapt and evolve it still is vulnerable
- it is a fact that parasites change from hosts
- phoresy is an association between two species in which one transports the other. This does not include killing the host (is possible, but it is not a condition under which you can call something a phoresy).
Answer:it's C and D
Explanation:it showed the answer
gene flow or migration between two populations will help maintain similarities between the species, therefore preventing (or slowing down) the process of speciation. and when the environment changes rapidly, this can cause an overall decrease in population size because of a failure to adapt adequately to environmental changes. i hope this helped <3