1) A single-celled nucleated, photosynthetic organism would belong to the kingdom Protista (protist). As Animalia and Plantae are not single-celled organisms, Fungi (such as those that cause Histoplasmosis) are not photosynthetic, and Archaea and Bacteria are non-nucleated, Protista is the only logical solution.
2) Dogs are more closely related to cats than lizards because they are both homeotherms while lizards are poikilotherms. In addition, dogs and cats both give birth to live young while lizards have placental pregnancies. Dogs and cats are mammals; lizards are reptiles.
3) Plants and fungi share commonalities in their stationary nature and manners of reproduction via sexual and asexual methods. Differences include a contrasting source of energy; plants grow through photosynthesis, but fungi grow through decomposing foreign sources.
4) Carl Linnaeus's scientific contribution was the creation of a method for naming live organisms.
5) Byrophytes are comprised of Hornworts, Liverworts, Mosses—these microscopic organisms utilize spore reproduction and have no means by which to move nutrients and water. These hardy plants can tolerate below freezing temperatures without a mortal affect.
6) The function of xylem and phloem share commonalities in that they both transfer internal fluids throughout the plant. Xylem act to counter gravity by transferring water from the root upward through the stem and leaves. Phloem act to move nutrients created through photosynthesis to other parts of the plant where those nutrients may be utilized.
7) The Aves species have three unique characteristics: feathers, bills, and furcula (a forked bone in the chest used to facilitate flight).
8) Homeostasis is managed in larger animals by the autonomic nervous system, the liver, the kidneys, the hypothalamus, and the endocrine system.