Answer:
Scientists can study tree rings in ice to learn more about past climates.
Explanation:
i think this is right one.
Answer: See the explanation below, please.
Explanation:
The immune system allows us to discriminate from the outsider.
There is innate immunity which we carry from birth and protects us against antigens; correspond to barriers that prevent harmful bodies from entering the body.
It is composed of some of these components:
- Skin and mucous membranes (physical barrier): the skin has microorganisms that inhibit the growth of pathogens.
-NK cells (natural killer): they are leukocytes that recognize changes in the cell surface of cells infected by viruses and tumor cells. These target cells are recognized by NK cells, which trigger cytotoxic response and destroy them.
- Neutrophils: white balloons with granules that release enzymes that destroy and digest cells.
-Cytokines (including interleukins 1 and 6, interferons, tumor necrosis factor: TNF): they are low molecular weight proteins that generate immune system response by recruiting or inhibiting the functions of specific cells (dendritic cells) or neutrophils, regulate proliferation and cell differentiation, activate or inhibit the expression of some genes.
How to cut what open? and a mask.
The organ called spleen breaks down worn out red blood cells, extract it's haemoglobin that will be transported to the bone marrow to produce new batches of red blood cells.
