Which statement best illustrates a biotic or an abiotic factor that is often found in a city park? decaying leaves are an abiotic factor because they are not living. rocks are an abiotic factor because they have never been alive. water in ponds is a biotic factor, because it provides a habitat for living things. oxygen is a biotic factor, because it is required for life and found in all living things.

sexual reproduction produces offspring with novel combinations of genes. species that reproduce sexually must maintain two different types of individuals, males and females, which can limit the ability to colonize new habitats as both sexes must be present.

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.