what is the approximate percentage of total fixed nitrogen attributed to human activities?
Of the annual global total of fixed nitrogen, human activities account for roughly 45%.
Nitrogen fixation is the global amount of nitrogen that gets assimilated by any living organism into another organic compound. The organic compound can be ammonia or nitrogen ions.
Of the total global annual nitrogen fixation, humans account for a great amount. The current estimation is that humans cause 45% of the nitrogen fixation annually. The leading causes of this high rate are the burning of fossil fuels and increased agricultural fertilizer use.
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name a difference between a plant cell and an animal cell.
Answer:
the cell wall, chloroplasts
Explanation:
plant cells have a cell wall, but animal cells do not
plant cells also have chloroplast, but animal cells don't
what will happen to a population of organisms that are in an environment with little to no oxygen?
Answer:
Hypoxia occurs when algae and other organisms die from lack of oxygen and available nutrients. Hypoxia events often follow algal blooms. The cyanobacteria, algae, and phytoplankton sink to the seafloor, and are decomposed by bacteria. This lack of oxygen creates dead zones in which most aquatic species cannot survive.
Explanation:
Hope this helps maybe...
What happens to the population of lynx as the number of snowshoe hares decreases?
antigen-presenting cells usually display processed antigens to t cells in the _____________.
Antigen-presenting cells usually display processed antigens to T cells in the LYMPH NODES. These nodes are regions of the body where lymphocytes are activated.
T cells are white blood cells (lymphocytes), which form part of the immune system.
These cells (T cells) develop in the bone marrow.
The lymph nodes are secondary lymphoid organs in which naive T cells that search for specific antigens examine antigen-presenting cells (APCs) for their activation.
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Which organelle is labeled i?
animal cell
Answer:
I believe the line is pointing to the nucleus, which is the green ball in the center of the cell
Explanation:
Name the following
he valve presents at the mouth of the pulmonary artery
Explanation:
The pulmonary valve (sometimes referred to as the pulmonic valve) is a valve of the heart that lies between the right ventricle and the pulmonary artery and has three cusps. It is one of the four valves of the heart and one of the two semilunar valves, the other being the aortic valve. Similar to the aortic valve, the pulmonary valve opens in ventricular systole, when the pressure in the right ventricle rises above the pressure in the pulmonary artery. At the end of ventricular systole, when the pressure in the right ventricle falls rapidly, the pressure in the pulmonary artery will close the pulmonary valve.
which trophic level is most vulnerable to extinction?
Answer:
predators since they depend on other animals
Explanation:
usefulness of earthworm
Answer:By their activity in the soil, earthworms offer many benefits: increased nutrient availability, better drainage, and a more stable soil structure, all of which help improve farm productivity. Worms feed on plant debris (dead roots, leaves, grasses, manure) and soil. ... Nitrogen in the casts is readily available to plants.
Explanation:
Earthworms have the ability to eat and mix large amount of soil and organic matter and deposit it in the form of casts. They also enhance incorporation and decomposition of organic matter, increase soil aggregate stability, improve porosity and water infiltration, and increase microbial activity.
Select all factors that would have no effect on increasing the rate of photosynthesis.
A
Increasing the darkness (Give plant more shade)
B
Increasing sunlight
C
Increase water
D
Increase oxygen
E
Increasing glucose
F
Increase carbon dioxide
a scientist is comparing the outer layer of an onion cell
Explanation:
Scientists compare the outer layer of onion cells with the outer layer of human skin cells. What makes the outer layer of onion cells unique compared to skin cells? Contains cellulose.
what is the function of carbohydrates for the body
Answer:
to provide energy to the body
Explanation:
why do histone genes have a very slow molecular clock?
Answer:
The structure of the histone gene must be conserved for DNA to function properly.
Explanation:
:)
1. A type of movement of substances across the cell membrane that requires no energy is --
A. cell mediated movement
B. facilitated diffusion
C. active transport
D. receptor protein action
Answer:
B. facilitated diffusion
Explanation:
The cell membrane is said to be semipermeable because
Answer:
it is made of phospholipid bilayer along with other various lipids, proteins, and carbohydrates
What is the function of the sporangium?
protects the mature gametes
protects the developing mother spore cells
forms haploid cells through mitosis
passes characteristics from one generation to the next
Answer:
protects the developing mother spore cells
Explanation:
got it right
Which of the following describe genes?
А.
a set of instructions encoded in mRNA
B
a set of instructions encoded in DNA
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с
a set of instructions encoded in tRNA
D
a set of instructions encoded in a protein
Explanation:
A gene is the basic physical and functional unit of heredity. Genes are made up of DNA. Some genes act as instructions to make molecules called proteins.
A directional response that allows plants to grow towards light is called:
Answer:
Phototropism
Explanation:
It is the directional response that allows plant to grow towards or in some cases away from a a source of light
before it was known as "science," this branch of study was called what?
Answer:
biology is the correct answer
Before it was known as "science," this branch of study was called Natural Philosophy.
What do you mean by science?The pursuit of knowledge is what is meant by the term "science." This approach describes and provides an explanation for natural occurrences based on observations and experiments. The term "science" can also refer to the arranged body of information that has been accumulated by individuals via the application of that system.
A person who works in a particular field of science and possesses in-depth knowledge about that field is called a scientist. Or, to be more general, anyone who studies or works in a scientific field is considered to be a scientist.
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which body system initiates the process of muscle contraction
Answer:
Nervous System
Explanation:
"Muscle contraction begins when the nervous system generates a signal. The signal, an impulse called an action potential, travels through a type of nerve cell called a motor neuron."
Concentration of water in a solution outside the cell is 30% The concentration of
water inside the cell is 70%. In what direction will the solvent move if diffusion
occurs? Is energy required?
Answer:
water will move out of the cell,energy is required
Explanation:
water moves through osmosis which is the movement of water molecules from a region of higher concentration to a region of lower concentration.
why are they assuming the large molecules will stay on their own side of the membrane?
Answer:
What is osmosis? Why are they assuming the large molecules will stay on their own side of the membrane? The membrane is semipermeable, so the membrane only allows some molecules through and not others. In this case, it doesn't allow the large molecules through.
Explanation:
Hope It Helps
It is assumed that the large molecules will stay on their own side of the cell membrane because the membrane is semipermeable which only allows the passage of some molecules in and out of the membrane.
What is a Cell membrane?A cell membrane may be defined as a type of biological membrane that significantly separates and protects the inner environment of all cells from the outside environment. It is semi-permeable in nature.
The cell membrane consists of a lipid bilayer that is semi-permeable. The cell membrane regulates the transport of materials entering and exiting the cell.
The ability of a molecule to travel across a membrane depends on its concentration, charge, and size. In general, molecules diffuse across membranes from areas of high concentration to low concentration. Cell membranes prevent charged molecules from entering the cell unless the cell maintains an electrical potential.
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microorganisms are found in nearly every environment and are said to be
Answer: microorganisms are found in nearly every environment and are said to be ubiquitous
Explanation:
Have a nice study time
just answer the questions and pull sentences 4-5
:(
Answer:
top carnivore is alligator sorry o dont really know much about the others hope this helps a little bit
a particularly active cell might contain large numbers of
For each biomolecule below, match the benefit provided to the body
a. Protein 1. Insulation and long-term energy
b. Lipids 2. Build lean muscle and strengthen tendons
c. Carbohydrates 3. Repair and Replicate DNA and RNA
d. Nucleic Acids 4. Provides quick, easily digested energy
Answer:
1. Protein - build lean muscle and strengthen tendons
2. Lipids - insulation and long-term energy
3. Carbohydrates - provides quick, easily digested energy
4. Nucleic Acids - repair and replicate DNA and RNA
Explanation:
a. Think of protein as what helps your muscles grow and strengthen
b. Think of lipids as fats (blubber, the extra fat, helps insulate seals from the cold)
c. carbohydrates are found in starch and bread products, and are used to help build up energy prior to marathons.
d. nucleic acids - think of nucleus; it is where genetic material is located, and also where DNA and RNA is located.
where does the energy used to produce atp in the light reactions of photosynthesis come from?
Answer:
I don't know it can you help me
Help, needed. Its for a grade and im confused.
Answer:
Point Y
Explanation:
When the ball has the greatest potential energy, it has the most movement/it's at it's fastest. You can easily figure out these questions usually by picking the point that is lowest on these ramps. If two points are at the same level, pick the point that leads from the ball going down the steepest ramp.
Answer:
Point Y
Explanation:
Hi guys can you please help me with number 3 a and b please..ASAP
PLEASE BE RELEVANT AND REAL ANSWERSSS ..I REALLY NEED THIS TO GRAD
Answer:
Okay so for A the thing that is wrong with this experiment is that Cindy has done quite a few things incorrectly. Firstly what her experiment was about. Being healthy is a good thing but then turning around and doing the exact opposite for a week can damage your body. Secondly, Running 4 miles after school is good but then for the next week she sits and watches tv for 3 hours. It doesn't make sense on how she measured her experiment. Cindy should have recorded the times when she ran four miles and then used the same time to watch Tv for the next week.
We can fix this experiment by maybe taking out the hot Cheetos from it as that's just not healthy. Secondly we can have Cindy record how many minutes/hours she ran in the 4 miles and use those same times to watch Tv so that it's even.
Explanation:
For part B firstly it's just not possible to predict the weather with your feet. Secondly your grandpa could easily lie and tell you their hurting or they could just always be sore. Lastly, His feet could be not sore and it still rains.
We can fix this experiment by may be doing something more realistic. But to stay on this instead of calling him you should maybe stay over so that in the morning you can tell whether or not his feet are sore then record for the rest of the day to see if it rains or not. If their not sore and it rains then we know he can't predict weather with his feet the same goes for if they were sore and didn't rain.
the ans consists of how many neurons in a pathway?
Answer:
The efferent pathways of the ANS consist of 2 neurons that transmit impulses from the CNS to the effector tissue. The preganglionic neuron originates in the CNS with its cell body in the lateral horn of the gray matter of the spinal cord or in the brainstem.
Explanation:
add me as brain