A significant percentage of pre-embryos fail to continue their development or to implant in the uterus. Explain what may happen to prevent development from continuing
What will be an ideal response?
Causes may include major chromosomal abnormalities in the zygote or an inhospitable uterine environment. Examples might be the presence of an IUD or low levels of estrogen and progesterone.
You might also like to view...
What is the function of a Toll-like receptor?
A. to bind to surface molecules present on phagocytes B. to bind to cytokines C. to bind to surface molecules present on pathogens D. to facilitate the extravasation of phagocytes
Explain the difference between plasmogamy and karyogamy
What will be an ideal response?
Three-spined stickleback fish (Gasterosteus aculeatus) show substantial heritable variation in gill-raker length related to differences in their diets
Longer gill rakers appear to function better for capturing open-water prey, while shorter gill rakers function better for capturing shallow-water prey. Which of the following types of selection is most likely to be found in a large lake (open water in the middle and shallow water around the sides) with a high density of these fish? A) directional selection B) stabilizing selection C) disruptive selection D) sexual selection
The immunological synapse refers to the
A) interaction between a T cell and an antigen-presenting cell to produce a specialized contact area for communication between these cells. B) activation of a B cell to become a plasma cell. C) interaction between lymphocytes and foreign antigens to produce memory cells. D) binding of a monocyte or macrophage to antigen so that it can act as an antigen-presenting cell. E) interaction of the many cytokines produced by different immunological cells.