So white blood cell’s(WBCs for short) main job is to fight infections.
They do this by swallowing the infection.
You see,WBCs do not have a permanent shape.this means that they enlarge and decrease size of parts of their body.So they grow two long arm like structures called pseudopodia which swallow the infection.(pseudopodia means false feet).
You can see the process in the photo I attached from google
Answer:
B
Explanation:
The distance of the Goldilocks zone ensures that water on the terrestrial planet is maintained in the liquid phase. This is because the distance from the star ensure it receives enough sunlight to keep the planet warm but not too hot that the water exists as vapor. Water in its liquid form is essential for maintaining life like here on earth.
<span>a. Fish have a single central heart; earthworms have several hearts.
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Multi cellular organisms are made up of billions of cells each specialized to a unique role and these cells are organized into structural and functional units such as tissues and organs.
For each cell and organ to function optimally, it requires oxygen and nutrients and needs carbon dioxide and metabolic waste taken away in a continuous, never ending process.
<span>A mechanism is needed to accomplish the important function of transporting the relevant materials to and from the cell. The circulatory system fits this bill splendidly. It is a specialized organ system which allows blood and lymph to flow through the entire body carrying nutrients such as glucose, amino acids and electrolytes as well as oxygen to each cell, at the same time carting away carbon dioxide and all sorts of metabolic waste over to excretory organs to be expelled from the body.
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Answer:
The correct answer is - option B. They are small because they lack a nucleus.
Explanation:
Red blood cells or erythrocytes are specialized cell that produce in bone marrow and have specific role such as carrying oxygen from lungs to deliver it to the various organs and carry out carbon dioxide.
In mammals these cells lack cell organelles such as nucleus and mitochondria, a major factor that determined its smaller size. The size of RBC are move through narrow vessels throughout a organism because of its specific size and shape that provide it space for hemoglobin and allow to be flexible and bend to move through narrow vessels.
Thus, the correct answer is : option B. They are small because they lack a nucleus.
