Answer:
That is administered and controlled
Step-by-step explanation:
A variable is the condition or a product that may vary without the influence of any investigator. Such variables can be found abundantly in our daily lives, ranging from air to sunlight. Controlling such variables ensures the limitation of their influence on the outcome of an experiment. In connection to this experiment, the variables that are controlled are the mineral content in the water, the amount of bacteria food, the amount of light and the the constant temperature of 20 degrees C.
If not administered or these variables controlled, the experiment would not clearly explain the impact of caffeine on the heart beat of the water fleas as other variables may have influenced it. Thus variables are controlled to study the singular impact of any agent or effect.
Xylem Phloem are the vascular tissues that transport the food, minerals and water within the plant. Xylem transport the water and minerals while Phloem transport food and nutrients. The movements in Xylem is unidirectional from roots to aerial parts while the movements in Phloem are bidirectional.
Answer:
While plant cells have chloroplasts to photosynthesize, they also require ATP for cellular functions, and do use oxygen to break down some of the sugar they produce in order to generate that ATP. They need mitochondria for this.
In particular, at night when there is no light, plants undergo cellular respiration since there is no sunlight to photosynthesize.
They do, however, produce far more sugar and oxygen through photosynthesis than they use up in respiration.
Answer: definetly A, food webs
Explanation:
the other options are not even related to organisms
When the capture starts to increase, the fish population
from 50 capture start to 100 capture start upsurges. At 200 capture start, though,
the population augmented in the beginning up until it touched 300 months where
it significantly dropped.
Numerous environmental factors can affect the populace of
fish. First, when there is a hurricane, the fish population will be affected
because the water will move and change.
Second, pollution. When individuals pollute the ocean, it
affects the fishes’ ability to live.
Lastly, when there is a lot of hunters that feed on fish. This
may cause many fishes to be consumed and their population will be reduced.
