Answer:
Tundra
Explanation:
Ocean is the most stable biome, provides the majority of earths food and oxygen.
Rainforest provide 20% of earths food production. Also stable.
Grasslands although the don't get much rain it doesn't compare to the harsh weather that Tundra's face.
Tundra's is a very fragile environment. The freezing cold temperatures makes it a very difficult environment to survive in the winter, and plants and animals have a hard time coping with any extra stresses and disturbances. Therefore making it the least stable out of the rest listed.
The answer is: <span><span>has antigens A and B on the red blood cells
</span>
Human blood contains either:
A antigens (A)
B antigens (B)
A and B antigens together (AB)
none of these antigens (O)
corresponding to the A,<span> B</span>,<span> AB</span>, and O blood types, respectively.
Antigens are molecules that can cause an immune response to be mounted against them in the form of antibodies. Antigen is an abbreviation for 'antibody generator'.
In the case of the ABO blood groups, the antigens are sugars on the red blood cells.
Antibodies are complex proteins made by certain immune cells, and these proteins have the ability to bind foreign material or microbes, which can block their harmful action and label them for quicker elimination.
Example:
When a person has a blood type with a particular antigen (e.g. A), he or she won't produce antibodies against that blood type, so they are safe to receive blood from individuals with similar blood types (won't be considered foreign). They can also receive blood from blood type O donors because they don't have any antigens that would cause an immune response.
But this person with blood type A, has antibodies against blood type B (to defend oneself from foreign material), so if they were transfused type B blood in this case, they would experience a dangerous immune reaction as the antibodies would bind the B antigens of the B blood type red blood cells.
<span>
Blood type O individuals are universal donors = can donate blood to anyone.
Blood type AB individuals are universal receivers = can receive blood from any group.</span></span>
Samir should work on his communication and presenting skills in the language to become more effective at participating in a formal discussion.
A group discussion is a conversation about a certain subject among a number of people. Be confident, relevant to the issue, considerate of others, and use good, clear English when speaking during a group conversation.
- Respect other speakers' contributions.
- You can learn something if you pay close attention to what other speakers have to say.
- Mention the things that fascinate you.
- Always keep in mind that a discussion is not a fight.
- Respect different points of view.
- Before you talk, give your contribution some thought.
- Try to stay on topic for the conversation.
learn more about communication here: brainly.com/question/26152499
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(C. The dinosaurs became extinct after the Cretaceous time period, after living on Earth for about 165 Million Years
