Generally all (animal) cells have different shapes because they do different things. each cell type has a specific role which it has to play in order to assist the body in working efficiently and functionally. thus their shape supports them to carry out these roles effectively.
plant cells are not necessarily square, but they due tend to have distinct edges and be somewhat rectangular. this structure is caused by the cell wall which is very rigid and therefore forces the cell to have a defined shape.
while plant and animal cells have structural similarities, they also differ in a few ways, including in shape. plant cells tend to be rectangular and have distinct edges, while animal cells vary widely in shape and tend to have rounder, more fluid edges. which statement best elaborates on the reason for this difference?
a) animal cells have rounded edges because they contain cell walls, while rigid plant cells do not need cell walls.
b) rectangular shapes plants absorb sunlight during photosynthesis, and round shapes animal cells absorb oxygen.
c) animal cells vary in shape because they have different functions, while plant cells are rigid to plants grow upright.

Competition occurs between species when

Neelaredoxin is a 15-kda protein that is a gene product common in anaerobic prokaryotes. it has superoxide-scavenging activity, and it is constitutively expressed. in addition, its expression is not further induced during its exposure to o2 or h2o2 (silva, g., et al. 2001. j. bacteriol. 183: 4413–4420). which of the following statements best describes neelaredoxin synthesis? a-neelaredoxin is produced at all times; levels are constant even when exposed to o2 or h2o2.b-neelaredoxin is produced at all times; exposure to o2 or h2o2 increases expression.c-neelaredoxin is produced at all times; exposure to o2 or h2o2 decreases or prevents expression.d-neelaredoxin is only produced when there is exposure to o2 or h2o2.

The tasmanian devil, a marsupial carnivore, is facing extinction due to devil facial tumor disease (dftd) which causes bulging cancerous lumps and lesions to erupt around the face and neck — often causing enough deformation to make seeing or eating difficult. dftd has evolved into a contagious cancer, a trait that is unique among cancers. devil mating behavior involves biting around the head and neck, allowing cells from one individual — especially cells from the crumbly dftd tumors — to be transferred to the wounds or face of a new individual. this marsupial was once found across australia, but sea levels rose, isolating the tasmanian population, while the australian population went extinct. what would be an outcome of genetic isolation that is likely to have impacted the spread of dftd? a) reduced territory puts diseased individuals in greater contact with non-diseased ones. b) inbreeding results in less variation in facial features so the cancer is generally fatal. c) genetic isolation has made it difficult for scientists to develop a vaccine against dftd. d) the lack of genetic variation in the immune system of tasmanian devils minimizes resistance to the disease.