What does this duplex uterus allow the animal to do? A. Allow for a single embryo
B. Allow for urine passage
C. Allow for blood flow
D. Allow for multiple embryos (In contrast, a simple uterus, like the kind has a single chamber for the development of a single embryo)​

Which is an advantage of having memory cells when a pathogen is encountered for a second time. a) the memory cells are what proliferate into clones of cells in response to the binding of an antigen. b) memory cells are vital to the primary immune response in that they immediately recognize pathogens even at the first encounter. c) memory cells are essentially effector cells that are short lived and attack antigens even without having a receptor specific to that antigen. d) it ensures that more lymphocytes with a receptor specific to a particular antigen will be present than in a host that had never encountered that pathogen.

Drag each description to the correct location on the image. not all descriptions will be used. describe the parts of a comet. the frozen part of the comet the atmosphere of gases and dust formed when the nucleus vaporizes tail made of small, solid dust particles tail made of ions that appears to point away from the comet's orbit

The “ecological footprint” left by a citizen of a developed nation is about four times larger than that left by a citizen of a developing nation. why is this the case?