Answer:
The immune system responds to antigens by producing cells that directly attack the pathogen, or by producing special proteins called antibodies.
Explanation:
Specific immune responses are triggered by antigens. Antigens are usually found on the surface of pathogens and are unique to that particular pathogen. The immune system responds to antigens by producing cells that directly attack the pathogen, or by producing special proteins called antibodies.
The immune system review (article) | Khan Academy
Answer:
TRUE
Explanation:
If the population follows a logistic growth curve, the graph of P vs t will look like the diagram below.
The rate of growth (P') increases slowly at first, then increases rapidly from 2 to 4, and then slows down, but always P > 0.
The graph has an inflection point at (3, 1000). That's the point at which the rate of growth starts slowing down.
When t < 3, P'' > 0.
When t = 3, P'' = 0.
When t > 3, P'' < 0, because the rate of population growth is slowing down.
Thus, if the population is in the final phase of logistic growth, the population is increasing at a decreasing rate (TRUE)..
Answer:
The correct answer is - they lack a nucleus, DNA, and organelles like the endoplasmic reticulum or mitochondria
Explanation:
Red blood cells are considered as the cells, carry oxygen with the help of hemoglobin protein present in it to the various parts of the body from the lungs and carry CO2 back to the lungs.
These cells are different from the normal cell as they do not participate in the protein synthesis due to the fact that they lack various cell organelle and cell components required. Nucleus and DNA are major components or organelle missing from these cells. In addition to these two, endoplasmic reticulum and mitochondria also missing from RBCs.
Streams that flow beneath melting glaciers leave long ridges of layered sediments, known as Esker. Eskers are formed within ice-walled tunnels by streams which flowed within and under glaciers. They tended to form around the time of the glacial maximum when the glacier was slow and sluggish and after the retaining ice walls melted away, stream deposits remained as long winding ridges.