10. Fully-formed vertebrates might not have a lot in common, but their embryos show more similarities. What do all vertebrate embryos have in common at some point in their development? *
A. Gill slits and lungs
B. Tails and lungs
C. Tails and gill slits
D. Tails and fins

Answers

Answer 1
Gill slits and tails
Answer 2
C. Tails and hill slits

Related Questions

What factors can affect the blood flow of the cardiovascular system? How can this be prevented and resolved?

Answers

Answer:

You need to know the factors that affect blood flow through the cardiovascular system: blood pressure, blood volume, resistance, disease and exercise.

Explanation:

Cardiovascular diseases (CVDs) affect your heart and blood vessels. Almost half of all adults in the U.S. have at least one form of heart disease. You may make lifestyle changes to manage cardiovascular disease or your healthcare provider may prescribe medications. The sooner you detect cardiovascular disease, the easier it is to treat.

Treatment plans can vary depending on your symptoms and the type of cardiovascular disease you have. Cardiovascular disease treatment may include:

Lifestyle changes: Examples include changing your diet, increasing your aerobic activity and quitting smoking or tobacco products (including vaping).
Medications: Your healthcare provider may prescribe medications to control cardiovascular disease. Medication type will depend on what kind of cardiovascular disease you have.

what is this compound

Answers

i believe the answer would be heptane
The compound is 2-methylpentane

Select the statement(s) that accurately describe ways to observe Earth's change over time.

A) Most of the rock on Earth's surface is sedimentary rock.

B) In undisturbed rock layers, the oldest rock is on the bottom and the youngest rock is on the top.

C) Earth's moving tectonic plates have created mountain ranges and ocean trenches.

D) Relative dating is used to determine the age of rock or fossils compared to other rock or fossils.

E) Only bones of ancient dead animals can eventually become fossils.

Answers

Answer:

A, B and/or C I think-

Explanation:

Because I'm pretty sure those are true-

The answer is A
Explanation it’s A

Write a caption and title for the image.

Answers

Answer: landslide likely area


this area is a slope with bent tree trunks and tension cracks

Explanation:

The answer is that the diagram is situated on a hill and through gravity and weather a landslide could be an likely outcome

Identify the flower parts from their descriptions.

A) These grains contain male gametes (sperm cells):


B) This structure contains female gametes (egg cells):


C) This colorful structure attracts pollinators to the flower:


D) This structure has a sticky surface to trap pollen grains:


E) This structure produces and stores pollen:


These structures allow sperm cells to move through the style:


F) This cup-like structure holds the flower:


G) These structures protect the maturing flower bud:


H) This structure contains the female organs of a flower:


I) This structure contains the male organs of a flower:

Answers

Answer:

I dunno if you still need help with this but:

A. pollen grains

B. Ovule

C. Petals

D. Stigma

E. Anther

These structures allow sperm cells to move through the style: Pollen Tube

F. Receptacle

G. Sepal

H. Pistil/Carpel

I. Stamen

Explanation:

Hope this helps :)

A. pollen grains
B. Ovule
C. Petals
D. Stigma
E. Anther
These structures allow sperm cells to move
through the style: Pollen Tube
F. Receptacle
G. Sepal
H. Pistil/Carpel
I. Stam

How do you convert animo acids into traits?

Answers

Answer:

its 50%

Explanation:

To convert you take 50% and turn into fraction which is 1/2

It’s 50% this is correct

12. What do many scientists conclude about vertebrates from studying their embryological development? *
A. Vertebrates with gills are more likely to survive than those without gills.
B. Vertebrates have changed, or evolved, over time.
C. Vertebrates might have evolved into one another.
D. All vertebrates might share a common ancestor.

Answers

Answer:

all vertebrates might share a common ancestor

Explanation:

it’s d, all vertebrates might share a common ancestor

Read the clues given below to classify an unknown organism.

Clue 1: A single-celled organism with no specialized organelles
Clue 2: Found in hot water springs and thermal vents

What is the correct classification of the organism?

Domain Bacteria; Kingdom Eubacteria
Domain Archaea; Kingdom Eubacteria
Domain Bacteria; Kingdom Archaebacteria
Domain Archaea; Kingdom Archaebacteria

Answers

Answer: domain archaea and kingdom archaebacteria I think

Explanation:

D, hope this helps you

WHat are the answers 1-10 on brainpop lymphatic system pls help

Answers

Answer:

1. both are made of blood and plasma

2. C, A, B

3. capillary walls must be very thin

4. a highway

5. harmful particles would get in your bloodstream

6. complimentary

7. it distributes fatty acids throughout the body

8. immune

9. white blood cells

10. garbage collector

Quiz Answers
1.D
2.D
3.C
4.B
5.A
6.B
7.D
8.C
9.D
10.D

What evidence do some scientists use to support the idea that certain organisms might be related to one another? *
A. Similarities (physically, genetically)
B. Names
C. Common ancestors
D. Vertebrates

Answers

Answer:

the fossil record, biogeography, comparative anatomy, comparative embryology, and molecular biology.

Explanation:

I hope that made it easier:)

Answer:

a or c

Explanation:

How does the diaphragm remove air from the lungs?
When the diaphragm pushes upward, it decreases the volume of the lungs, pushing air out.
When the diaphragm pushes upward, it increases the volume of the lungs, pushing air out.
When the diaphragm pulls downward, it increases the volume of the lungs, pushing air out.
When the diaphragm pulls downward, it decreases the volume of the lungs, pushing air out.

Answers

Answer: When, the diaphragm pushes upward, it decreases the volume of the lungs, pushing air out.

Explanation:

In exhalation, the diaphragm move upward and the chest wall muscles relax, causing the chest cavity to get smaller and push air out of the respiratory system through the nose or mouth.

When you breathe in, the diaphragm moves downward toward the abdomen, and the rib muscles pull the ribs upward and outward. This makes the chest cavity bigger and pulls air through the nose or mouth into the lungs.


When the diaphragm pushes upward, it decreases the volume of the lungs, pushing air out.


Discuss the following aspects of the cardiovascular system.
-Anatomy
-Function of individual organs
-Blood flow

Answers

Me and my friends reviews and wrote up this… not sure wether it answers everything but if it does pls give me brainliest !

Your circulatory system is made up of several parts, including your:

Heart. This muscular organ works to pump blood throughout your body via an intricate network of blood vessels.
Arteries. These thick-walled blood vessels carry oxygenated blood away from your heart.
Veins. These blood vessels carry deoxygenated blood back toward your heart.
Capillaries. These tiny blood vessels facilitate the exchange of oxygen, nutrients, and waste between your circulatory system and your organs and tissues.
Interesting facts about the circulatory system
Your heart pumps about 5 liters of blood per minuteTrusted Source, but it’s only about the size of your fistTrusted Source.
It’s estimated that in a 70-year period, your heart will beat over 2.5 billion timesTrusted Source.
In most adult humans, a normal resting heart rate is between 60 to 100 beats per minuteTrusted Source.
The total length of all of the blood vessels in your body is about 60,000 miles.
Capillaries are your most numerous blood vessels and also the smallest. Red blood cells often have to move through the capillaries in single-file.
Your blood pressure changes throughout the day. It’s lowest when you’re asleep, and it peaks in the middle of the afternoon.
How does it work?
Your circulatory system is vital to your survival. Its function is to distribute blood and other nutrients to all your body’s organs and tissues.

The small blood vessels called capillaries facilitate the exchange of oxygen and nutrients between your blood and the cells in your body. Carbon dioxide and other waste products, which are expelled from your body, are also exchanged via your capillaries. These tiny capillaries are spread throughout your body so that they can reach every cell.

Let’s follow the blood on a simple loop through the circulatory system to see how it works:

Oxygen-depleted blood returns to your heart (the right side) via the veins.
Your heart pumps this blood to the lungs. In the lungs, the blood gets rid of carbon dioxide and picks up fresh oxygen.
Newly oxygenated blood returns to the other side of the heart (the left side), where it’s then pumped into the arteries.
Eventually, the blood enters the capillaries. Here, it releases oxygen and nutrients to your body’s organs and tissues. It then picks up carbon dioxide and other waste products.
The oxygen-depleted blood returns to the heart through the veins, and the cycle begins all over again.
The circulatory system can also respond to various stimuli to regulate the flow of blood. Examples of these stimuli include changes in:

blood volume
hormones
electrolytes
Circulatory system conditions
Below, we’ll explore some of the most common conditions that can affect the health of your circulatory system.

Atherosclerosis

Atherosclerosis is when plaque builds up along the walls of your arteries. Risk factors that can contribute to plaque buildup include:

high blood pressure
high cholesterol
tobacco use
diabetes
an unhealthy diet
low levels of physical activity
being overweight or obese
Atherosclerosis can gradually make the arteries narrower, affecting the amount of blood that can flow through them. Because of this, organs and tissues may not get enough oxygen.

When atherosclerosis affects the arteries of your heart, it’s called coronary artery disease. Other arteries in your body can also be affected as well. This is called peripheral artery disease, which affects how well blood can flow to your legs, feet, arms, and hands.

In some cases, an artery may become completely blocked by plaque or a blood clot. When this happens, a heart attack or stroke can occur.

High blood pressure

Your blood pressure is the force that your blood exerts on the walls of your arteries as your heart pumps. High blood pressure can eventually damage your heart and blood vessels, as well as other organs like your brain, kidneys, and eyes.

Angina

Angina is chest pain that occurs when your heart isn’t getting enough oxygen. It’s often caused by coronary artery disease, which makes the arteries supplying the heart narrower due to plaque buildup.

Arrhythmia

An arrhythmia is an abnormal heart rhythm. When you have an arrhythmia, your heart may be beating too fast (tachycardia), too slowly (bradycardia), or irregularly. It happens due to changes in the heart or its electrical signals.

Varicose veins

Your veins contain valves that help keep oxygen-depleted blood flowing toward your heart. When these valves fail, blood collects in the veins, which can cause them to bulge and become swollen or painful.

Varicose veins most often appear on the lower legs.
A antomy is the heart the veins arteries
Function is a transport blood and nutrients to parts of the body
Blood flow control by heart , veins and areteries

Read about the life cycle of an apple tree, and think about the role apples play in reproduction. Describe how apples help apple trees to reproduce. In other words, for an apple tree, what is the advantage of producing fruit as opposed to simply dropping its seeds on the ground? ⊄ pls help asap⊅

Answers

Answer:

Since the apple is food, animals eat the apple( seed and all) and take a poop in a different area.

Explanation:

Since apple seeds don’t digest easy, it has fresh, fertile ground to grow in.

The fruit or flower on any plant has a main role of reproduction, the apples contain seeds which is how the tree reproduces itself. An animal may obtain and consume the fruit carrying the seeds with it, spreading the multitude of seeds near and/or far. Planting more trees in the area, and not all cooped up in one spot, so they’re not fighting for resources.

On your own: Create at least two more paths on the Gizmo. List the energy conversions that happen along each path.

Answers

Which gizmo are you doing

which marble reached the ground first,A or B? why do you think is this so?

Answers

Answer:

B

Explanation:

its B becuase iknow it becuase teacher told me!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer:

its b the person above me is correct

Explanation:

nuclear power:

description: renewable? non-renewable?
pros and cons
where it is found
how it is recovered
brief history
how it is stored in the source
how energy is released
economic impact
environmental impact
future of energy source

i know this is a lot, just answer whatever you can!

Answers

I believe that nuclear power is renewable
Non renewable

Pros lots of energy

Cons dangerous and needs constant maintenance

What is the difference between Organic and Inorganic material? Provide 3 examples of each and identify which one is likely to take the longest to break down in a landfill.

Answers

Answer:

The primary difference between organic vs. inorganic compounds is that organic compounds always contain carbon while most inorganic compounds do not contain carbon. Also, nearly all organic compounds contain carbon-hydrogen or C-H bonds.

Explanation:

Inorganic: 1. ammonia 2. all metals 3. calcium

Organic: 1. grass 2. wood 3. flowers

Inorganic materials would take the longest to break down in a landfill.

What are some ways that animal structure and functions differ depending on the animal’s environment?

Answers

Different animals use their body parts in different ways to see, hear, grasp objects, protect themselves, move from place to place, and seek, find, and take in food, water and air. Plants also have different parts (roots, stems, leaves, flowers, fruits) that help them survive and grow.

Internal structures are located within an organism. The functions of internal and external structures work together as part of a system in an organism. These structures support an organism's survival, growth, behavior, and reproduction.

Many scientists state that living things have evolved, or changed, over time. What evidence do they use to support this idea? *
A. Embryos from vertebrates often look very similar to one another, depending on their stage of development.
B. Modern animals share many traits and have similar genetic material (DNA).
C. There are patterns of change in the fossil record, showing differences among older and younger fossils that are similar.
D. Many creatures that were once alive are no longer on the planet (they have gone extinct).

Answers

Answer:

C

Explanation:

Overtime animals evolve to adapt to their enviroment but some times still look simpilar e.g a giraffe once had a small neck yet the same pattern on there skin now giraffes have long necks to reach the leaves on a tree.

I think The correct answer is C

Which term names the main components of proteins?


amino acids


fats


lipids


sugars





Ayuda graded test

Answers

amino acids
hope this helps! have a great day
Amino acids



Amino acids are molecules that combine to form proteins. Amino acids and proteins are the building blocks of life!

The gene being transferred is also cut. Will the restriction enzymes being used to cut the plasmid be used to cut the original DNA?

Answers

Explanation:

When a restriction enzyme such as BamHI is used to cut the plasmid, it would cut the circle at one place. The cut would open up the circle in the LacZ gene. This is because gene cloners have placed a piece of DNA that has many restriction enzyme cutting sites within the LacZ gene.

The answer would be Yes!

1- Some organisms rely on each other for necessities such as food and shelter t or f
2- Organisms can defend themselves from predators that try to eat them t or f

Answers

Answer:

1. F

2. T

Explanation:

If you don't mean true or false please say so

Both are true hope this helps

Selective breeding has been used to create plants that are more resistant to disease. Of what is this an example?

Choose the correct answer.

Answers

Answer:

protective plants and toxic plants

Answer:

the person above me is correct

Explanation:

PLS HELP ME (100 points) (ill give a brainliest) ( any point stealing or links or unrelated answers will get reported)

Patient A came to the clinic after having a bike accident. She has severe pain in her left forearm. The pain increases when she moves the arm, and her arm is quite swollen. The X-ray shows an abnormality with the radius bone in the forearm.

Based on Patient A's history, which diagnosis is most logical?
Muscle sprain
Nerve damage
Broken or fractured bone

•Which of the following systems is affected by the broken arm? Select all that apply.
Muscular
Nervous
Skeletal

•Use the internet to search for treatments for broken bones.
Record possible treatments on your activity report.
Make sure you list the websites you use to create a treatment plan.

•Patient B came to the clinic complaining of numbness and tingling in his right foot. He described the pain as feeling like pins and needles. There is no swelling, bruising, or redness. The X-ray shows no breaks or fractures, but the patient states that he has type 2 diabetes. A blood glucose test shows high blood glucose levels.

•Based on Patient B's history, which diagnosis is most logical?
Broken or fractured bone
Muscle sprain
Nerve damage

•Important: Fill in the diagnosis on your activity report.


•Which of the following systems is affected by the nerve damage? Select all that apply.
Skeletal
Muscular
Nervous

•Use the internet to search for diabetic peripheral neuropathy treatments.
Record possible treatments on your activity report.

•Make sure you list the websites you use to create a treatment plan.

•Patient C came to the clinic complaining of pain in her left calf. Her calf is swollen and hurts even when at rest. Before coming in to the clinic, Patient C had been running track. All of a sudden, she felt tightness and pain in the back of her calf. The X-ray shows no breaks or fractures, and an MRI shows no nerve damage.

•Based on Patient C's history, which diagnosis is most logical?
Muscle sprain
Nerve damage
Broken or fractured bone

•Important: Fill in the diagnosis on your activity report.

•Which of the following systems is affected by the muscle sprain in the calf? Select all that apply.
Skeletal
Nervous
Muscular

•Use the internet to search for muscle sprain treatments.
Record possible treatments on your activity report.
Make sure you list the websites you use to create a treatment plan.

Answers

Answer:

Explanation:

fractured bone as the arm is swollen

Bruising can happen with almost any kind of tissue damage, including blood leaking from a broken bone. 1   The bigger the area of bruising, the more likely the damage is deep—possibly bone deep. Broken bones often swell. Swelling can be a sign that it's broken.

it will affect your skeletal system as you are unable to moth that part of your body and it also affect your muscular system as you can move your arm.

Broken bones are one of the most common orthopedic injuries. Fractures require treatment which may be as simple as rest, or as invasive as surgery. There are many factors that must be considered to determine the most appropriate treatment of a broken bone including: Some of the most frequently used fracture treatments are described here

that is most likely nerve damage as there is no bruising and it is numb so here nerve damage will be most logical.

muscular and nervous system as you are unable to feel or move your muscle.

muscle strain as it is when she overexercise her muscle which I sometimes experience at night.

it will most likely affect your muscular system

For immediate self-care of a sprain, try the R.I.C.E. approach — rest, ice, compression, elevation: Rest. Avoid activities that cause pain, swelling or discomfort. But don't avoid all physical activity.

Patient A has a fracture, if there is an abnormality in the x-ray (which only detects bones) there is something wrong the bone.

skeletal and muscular, the muscle is swollen and affected by the break in the skeletal system.

A treatment would be icing the forearm, and applying a cast.

Patient 2 has nerve damage
The nervous system is affected by the damage.
A treatment would be managing blood sugar levels because the patient has type 2 diabetes. Nerve pain medication would block pain by the damaged nerves.

Patient C has a muscle sprain because when she ran, she might have stepped incorrectly, straining the muscle.
The muscular system is affected by this.
Cold compressions, keeping the calf elevated and rest.


An atom contains 3 protons, 3 electrons, and 4 neutrons. Which of the following statements
correctly describes the nucleus of this atom?
A the nucleus contains 3 positively charged particles
B the nucleus contains 3 negatively charged particles
C the nucleus contains 3 positively charged particles and 4 neutrally charged particles
D the nucleus contains 3 negatively charged particles and 4 neutrally charged particles

Answers

C because a nucleus contains only positive particles and neutral particles.
Answer: C

C describes more of the nucleus than A does, and is correct in stating the amount of positive charged particles and neutral charged particles.

1) What determines which
genes will be an advantage
and which ones will be a
disadvantage?


2) How does this experiment
illustrate Darwin's theory of
Natural Selection?

Answers

Answer:

1. While you do inherit certain genes from your mother and father, you will get separate versions of those genes meaning there will be advantages and disadvantages.

2. Charles Darwin, Natural selection explains how the genetic traits of a species may change over time. This may lead to speciation and the formation of a distinct new species.

Explanation:

1. Something that is an advantage towards the person achieving the genes is whether or not that trait is beneficial. For example, your body size can be determined by your mother or father which can lead to negative health or positive health. That can be a disadvantage (shape, being born with asthma, inheriting a mental illness). All can be achieved because of a parent.

2. Charles Darwin and his theory illustrate genes because as a parent hands over a gene during pregnancy it can be altered because it is a different version of that gene and that can lead to different species whether it is visible or not.

8.Examine this skeleton of an extinct animal. Which of the animals below is most likely to be closely related to it? *


A. Clouded leopard

B. Rhinoseros

C. Whale

D. Frog

Answers

i would say A clouded leopard because it wouldn’t match the body types of the other animals

The skeleton is of Clouded leopard.

What are Extinct animal?

Extinct species of animals are those that have stopped reproducing, perished, and ceased to exist. The extinction of a species is said to occur at the time of its last member's death.

Over the past 500 years, more than 900 species have become extinct. Due to habitat loss, a shortage of food supply, hunting, pollution, climate change, and excessive consumption, animals go extinct.

One of the most well-known extinct species is the dinosaur; it is thought that a meteor impact and/or numerous volcanic eruptions were responsible for its extinction.

Therefore, The skeleton is of Clouded leopard.

To learn more about Leapord, refer to the link:

https://brainly.com/question/27428495

#SPJ2

please help, I'll give brainliest!
Create an energy path in the Gizmo, starting at the Sun. For each step of the path, describe the energy conversion that takes place. The first one is done for you.

please list types of energy (i.e. kinetic energy, electrical current, etc.), not just how you get from one step to the next. see the example attached :)

Answers

Answer:

Sun— Nuclear is converted to heat and light energy.

Corn absorbs sunlight in order to produce sugars and oxygen for plant growth.

Corn is fermented to produce ethanol, which is burned to power generators to give an electrical current The speaker takes the electrical current and produces sound.

Explanation:

I answered to the best of my abilities. I hope this helps =)

Question 2
Which letter best represents the amplitude?
А
B
C
D

Answers

Answer:

EXPLINATION BELOW……


B

because B includes the midpoint and the top of the line

It’s B it includes the midpoint at the top of the line so it would be B

Which two systems work together when you pull your hand away from a hot stove?
digestive and muscular
nervous and respiratory
circulatory and digestive
muscular and nervous

Answers

Answer:

I think it would be muscular and nervous

Explanation:

Hope this helps:)....if it don't then sorry for wasting your time and may God bless you:)

Muscular and nervous because when you burn yourself on a stove the first thing you do is move your hand fast away from it. Our muscles help us to move our arms legs it’s attached to our tendon and when we nervous it sends that to our brain and we quickly move and when you burn yourself the first thing your brain do is tell you to quickly remove your hand. Sorry this is kinda long but I hope this helps good luck!
Other Questions
You discover a mutation in the protein-coding sequence of a gene that does not change the amino acid sequence. This makes sense because __________. The Nazi Party was a fascist movement that appealed to the poor and humiliated people of Germany. What ideas was this movement based upon?A Industrial strength, economic independence and socialismB Racial purity, strong currency and limited governmentC National pride, military rule and racial purityD National pride, military rule and racial equality The Voting Rights Act ended poll taxes. literacy tests. voter segregation. gender discrimination Juan puts 36,500 milliliters of gasoline in his vehicle. A liter of gasoline costs $1.68.How much did the gasoline cost?Enter your answer in the box. What is your favorite color of the alphabet yes or no? Psychologists found over 18,000 different traits by compiling those listed in a dictionary..True.False The height of a triangular truss is 5 ft less than the base. The amount of drywall needed to cover the triangular area is 84 ft2. Find the base and height of the triangle to the nearest tenth of a foot. Statuses and their related roles determine the structure of the various groups in society. when these statuses and roles are organized to satisfy one or more of the basic needs of society, the group is called a(n) a. pastoral society. c. preindustrial society. b. social institution. d. agricultural society. Lindsey purchased one pet carrier that $21.89 and two bags of cat food that cost $16.46 each what was the total cost of these items? The second term is 5 the fourth term is 12 and the seventh term is 22. 5 what is the first term? Parents share that their toddler often needs a snack in between meals. Which snack choice is nutritious enough to give the toddler energy but also may help prevent dental caries What is true about cells in animals?1. Some animal cells can produce food.2. They can produce food.3. They cannot produce food.4. They are the same as plant cells. 9. Which compound is the least soluble at 20 C? Use the distributive property and then simplify the expression.3(x-8)+6(x+4) The consequences of first world war were the causes of second world war Evaluate the piecewise function by matching the domain values with the range values. The short sides of a rectangle are 2 inches. The long sides of the same rectangle are three less than a certain number of inches.Suppose that you are given the value of the unknown number. Verbally describe two methods for finding the area of this rectangle. Use complete sentences in your answer.PLS HELP A paperweight in the shape of a rectangular prism is shown:If a cross section of the paperweight is cut diagonal to the base, which shape describes the cross section? Square Triangle Hexagon Parallelogram WILL GIVE BRAINLIEST! THANKSSS! 5 STARS! PLEASE HELP ME!!!As the Black Death spread up the Italian peninsula, into France, Germany, and further north, people alive in the 1300s felt that there was little they could do to protect themselves. What option might have been open to England and Scotland that the rest of Europe could not take advantage of?England and Scotland are on an island so they could have closed their shores to ships.England and Scotland had access to scientists who should have found a medicine.England and Scotland have cold, wet environments that should have killed the bacteria.England and Scotland had access to wool that could be used to create masks. How many grams of sulfur are required in the preparation of 35.7 moles of sulfur dioxide Sg + O2 SO2