Answer:
Forest floor
Explanation:
Tropical rainforest is characterized by high rainfall that allows a diverse growth of plant species. The different species of plants and animals species that make up a rainforest are found in different layers. There are four layers or sections in the rainforest from top to bottom viz: emergent layer, canopy, understory and forest floor.
Since the layers are classified from top to bottom, each layer receives different amount of rainfall and sunlight. According to the question, the FOREST FLOOR receives the least amount of sunlight making it the darkest section of the rainforest. Due to the inhibited penetration of sunlight into this layer, it usually does not support any plant growth.
<span>cm x (in/cm) = in
21 cm x (1 in / 2.54 cm) = 8.3677 in </span>
The average red blood cell lives for 120 days.
2. There are 2.5 trillion (give or take) of red blood cells in your body at any moment. To maintain this number, about two and a half million new ones need to be produced every second by your bone marrow.That's like a new population of the city of Toronto every second.
3. Considering all the tissues and cells in your body, 25 million new cells are being produced each second.That's a little less than the population of Canada - every second !
4. A red blood cell can circumnavigate your body in under 20 seconds.
5. Nerve Impulses travel at over 400 km/hr (25 mi/hr).
6. A sneeze generates a wind of 166 km/hr (100 mi/hr), and a cough moves out at 100 km/hr(60 mi/hr).
7. Our heart beats around 100,00 times every day.
8. Our blood is on a 60,000-mile journey.
Answer:
A. engulfing of small photosynthetic prokaryotes by larger cell
Explanation:
The endosymbiotic theory states that some of the organelles in today's eukaryotic cells were once prokaryotic microbes. In this theory, the first eukaryotic cell was probably an amoeba-like cell that got nutrients by phagocytosis and contained a nucleus that formed when a piece of the cytoplasmic membrane pinched off around the chromosomes. Some of these amoeba-like organisms ingested prokaryotic cells that then survived within the organism and developed a symbiotic relationship.
Some Evidence for this is based on the following:
1. Chloroplasts are the same size as prokaryotic cells, divide by binary fission, and, like bacteria, have Fts proteins at their division plane.
2. The mitochondria are the same size as prokaryotic cells, divide by binary fission, and the mitochondria of some protists have Fts homologs at their division plane.
3. Mitochondria and chloroplasts have their own DNA that is circular, not linear.
4. Mitochondria and chloroplasts have their own ribosomes that have 30S and 50S subunits, not 40S and 60S.
5. Several more primitive eukaryotic microbes, such as Giardia and Trichomonas have a nuclear membrane but no mitochondria.
No, because a single observation on one planet is not sufficient to discredit a theory.
There are too much variables that would cause that data, and just observing one planet is the same as ignoring all the potential variables.
