Answer:
C. Standing upright allowed for sightlines over tall grasses and savanna shrubbery
Explanation:
One of the most accepted theories about the development of bipedalism of the hominids is that it was mostly because of the tall grasses and shrubs, so standing upright was providing them with better view. Once the environment changed, and the tropical rainforest was turned into savanna, the hominid ancestors had to adapt in order to survive. Being helpless against the large predators, they needed something in order to be able to detect them from bigger distance so that they can avoid them. The solution seemed to be to be able to see above the tall grasses and shrubs, which meant that they started to use their legs more and more in order to stand up taller. This gradually led to better development of legs for upright standing and walking, also causing changes in the structure of the body, providing the hominids with an adaptation that enabled them to survive in the very dangerous environment.
Answer:
plant: This Elodea leaf cell exemplifies a typical plant cell. It has a nucleus, and a stiff cell wall which gives the cell its box-like shape. The numerous green chloroplasts allow the cell to make its own food (by photosynthesis).
The central vacuole takes up most of the volume of the cell. It is transparent, but you can see where it's pressing the chloroplasts up against the cell wall, especially at the ends of the cell.
Like animal cells, the cytoplasm of this plant cell is bordered by a cell membrane. The membrane is so thin and transparent that you can't see it, but it is pressed against the inside of the cell wall.
animal :This human cheek cell is a good example of a typical animal cell. It has a prominent nucleus and a flexible cell membrane which gives the cell its irregular, soft-looking shape.
Like most eukaryotic cells, this cell is very large compared to prokaryotic cells. For scale, notice the pair of dark blue bacteria cells sticking to the right edge of the cheek cell. The bacteria are only a fraction of the size of the nucleus, but their tiny size is typical for bacteria.
The mitochondria. An organelle with a very curious history....
Weather conditions, temperature, and Food availability
