answer 18 and 19 Please help I will mark brainliest

Answer:

However, some helium atoms have more or less than two neutrons. Atoms with the same number of protons but different numbers of neutrons are called isotopes. Because the number of neutrons can vary for a given element, the mass numbers of different atoms of an element may also vary.

Answer:

Celia should tell the teacher and wash her hands and arms twice.

Explanation:

She should tell the teacher because if she is unsure of what to do, the teacher can help her. If there is no teacher present, she should wash her hands and arms twice to remove as much of the chemical as possible. Then she should call a poison help or chemical help center if she is unsure of what to do next.

Answer:

B.

Explanation:

Answer: Early eukaryotic cells engulfed prokaryotic cells, which later became mitochondria and chloroplasts.

Explanation: just did the test its right.

Assuming this is a true/false question, the answer would be false.

According to the law of conservation of energy, energy is neither created nor destroyed; it simply changes forms.

Unless you are saying that some energy would be lost as heat, This is true.

Answer:

ae you trying to find the meaning?

Explanation:

The law of conservation of energy states that energy can neither be created nor destroyed - only converted from one form of energy to another. This means that a system always has the same amount of energy, unless it's added from the outside. The only way to use energy is to transform energy from one form to another.

ex: the cue ball is shot at a stationary 8 ball. The cue ball has energy. When the cue ball hits the 8 ball, the energy transfers from the cue ball to the 8 ball, sending the 8 ball into motion. The cue ball loses energy because the energy it had has been transferred to the 8 ball, so the cue ball slows down.

forest fires,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Explanation:

Both flukes and tapeworms are parasites with vertebrate hosts, including human hosts. Flukes live in the host's circulatory system or liver. Tapeworms live in the host's digestive system.

Answer:

any two flatworms are

1. tapeworm

2. liverworm

Explanation:

hopes it could help you

Answer:

stem cells

Explanation:

Answer:

A) Group X = Rose ,mango tree,marigold,palm tree

B) This is the answer of group X =Rose ,mango

This is the answer of group Y =Fern ,pine trees

Explanation:

Answer:

jen, from my heart im saying i lu.v u for real

its been almost 5 months weren't having the same old c.hat we used to have.

ik that ur scared to c.hat with  me since the day ur mom caught u

but still the old memories keep coming into me how many times i try to forget u, i still lu.v u jen still lu.v u

and as i made u a promise that one day we'll meet, i still keep thqat word and that day even if its just one day, we're gonna enjoy the max we could

i'll be waiting for that moment and i hope u would be too...

still lu.v u :(  .......

Answer:

Im pretty sure its A the phagocytes.

Explanation:

Answer:

Decomposers break down dead organisms into nutrients and gases so that they can be used by other organisms. Nutrients can enter or exit an ecosystem at any point and can cycle around the planet.

Answer:

False

Explanation:

Answer:

Carbon dioxide

Answer:

Carbon Dioxide

Explanation:

Answer:

Aerobic means 'with air' and refers to the body producing energy with the use of oxygen. This typically involves any exercise that lasts longer than two minutes in duration. ... Anaerobic means 'without air' and refers to the body producing energy without oxygen.

Explanation:

hope this helps if not i'll try to figure out the answer for you

I think the answer is B. Immigration must outpace emigration. Hope this helps!

Hardy-Weinberg equilibrium is the principle of the genetic variation being constant. Each allele must be equally beneficial for a population to be in equilibrium. Thus, option C is correct.

Hardy-Weinberg equilibrium states the invariant nature of genetic variation when there are no disturbing factors in a population. For an equilibrium condition, the population should have a large size. Each allele must be equally beneficial so that there is no genetic drift.

There should be no immigration or emigration of the organism in a particular population as it affects the generation and individuals. Also, there must be no spontaneous mutations for the variation to occur.

Therefore, each allele must be equally beneficial for equilibrium.

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Natural selection is the process through which populations of living organisms adapt and change. Individuals in a population are naturally variable, meaning that they are all different in some ways. This variation means that some individuals have traits better suited to the environment than others.

Answer:

Cancer is basically a disease of uncontrolled cell division. Its development and progression are usually linked to a series of changes in the activity of cell cycle regulators. For example, inhibitors of the cell cycle keep cells from dividing when conditions aren’t right, so too little activity of these inhibitors can promote cancer. Similarly, positive regulators of cell division can lead to cancer if they are too active. In most cases, these changes in activity are due to mutations in the genes that encode cell cycle regulator proteins.

Explanation:

The mutated (cancer) cells show the evidence that they do not respond to contact inhibition because there is no stopping of division of the cells.

Normal cells show response to contact inhibition when they come into contact with other cells, so they stop moving and dividing.

While on the other hand, The mutated (cancer) cells show the evidence that they do not respond to contact inhibition because there is no stopping of division of the cells so we can conclude that no stopping of division occurs which is the evidence that the cancer cells show no response to contact inhibition.

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Answer:

B Sun > Algae > Shrimp > Red drum

Answer:

Catastrophism, doctrine that explains the differences in fossil forms encountered in successive stratigraphic levels as being the product of repeated cataclysmic occurrences and repeated new creations. ... This doctrine generally is associated with the great French naturalist Baron Georges Cuvier

The mechanism of catastrophism directly explains the process of fossil formation. It described the natural history that has been punctuated by catastrophic events that altered the way life developed and rocks were deposited.

Catastrophism may be defined as a type of geologic doctrine that significant changes in the earth's crust that have in the past been brought about suddenly by a series of events like mass extinction.

This catastrophic doctrine explains the differences in fossil forms encountered in successive stratigraphic levels as being the product of repeated cataclysmic occurrences and repeated new creations.

Therefore, the mechanism of catastrophism directly explains the process of fossil formation.

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A plant is placed near a window. Instead of growing straight up, the plant grows to the side. This plant demonstrates phototropism. Therefore, option A is correct.

A plant can maximize photosynthetic light absorption in the aerial portion and water and nutrient uptake in the roots by using phototropism, or the differential cell elongation displayed by a plant organ in response to directed blue light.

Auxin is a hormone found at the ends of leaves and stems that reacts to light. It enables the plant to grow in a way that is favourable to the light source.

When a plant is placed near a window. Instead of growing straight up, the plant grows to the side. Then, this plant demonstrates phototropism. Therefore, option A is correct.

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Answer:

40

Explanation:

they're usually the same

One part of the cell theory is that pre-existing cells can form more cells

This means that cells that currently exist are capable of creating more cells, however it’s a slow process

Answer:

Carbon dioxide is a colorless gas with a density about 53% higher than that of dry air. Carbon dioxide molecules consist of a carbon atom covalently double bonded to two oxygen atoms. It occurs naturally in Earth's atmosphere as a trace gas.

Answer:

The air that you breathe out. Also it is what plants breathe in.

Explanation:

Hope this helps!!

Answer:

at the moment i am thinking of 3 different hydra, marvel, mythical creature and creation on sexual reproduction between plants. If you could tell me the subject i could explain it to you. :)

Explanation:

Answer:

recombinant DNA

Explanation:

In molecular biology, recombinant DNA molecules are genetic sequences formed by combining DNA material from different sources (i.e., organisms, populations, species, etc). Proteins produced from DNA recombinant molecules are known as recombinant proteins. Molecular cloning is the most widely used technique in molecular biology in order to produce recombinant DNA molecules. In this technique, a cloning vector such as, for example, a plasmid of a bacterium, is used to insert a foreign DNA fragment into another cell which is then expressed in the host cell.

Answer:

No of groups studied

As All other factors will effect the result ofvthe experiment.

But no matter how many groups you take to study they will show the same result

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Answer:

C

Explanation:

the answer is C bc I read this and u can site it in the text

Answer:

dunes, beaches, and maybe estuaries

Explanation:

i hope thats right.....

Answer:

Both Mars and Saturn have rings.

Answer:

A

Explanation:

found in acid and bases

Answer to 1:Yes the Zonkey is alive,not all organisms can reproduce. Some people are born with rare genetics were they can't give birth,so even if the Zonkey is sterile and can't produces it own offspring it is alive.

Answer to 2:Yes a virus is alive,it attacks the host and contains/kill other cells in your body. They also can multiple. If they can multiply and even attack and kill other cells they are alive.