Unicellular organisms are devoid of circulatory systems and will be found living in moist or watery environments to facilitate uptake of nutrients and gases and expulsion of waste by the process of diffusion.
Their cell is structured such that it can engage in direct exchange of substances with its environment. Water serves as the perfect medium or environment through which this exchange can occur.
Gases and nutrients simply diffuse into the cell or are moved into the cell by means of active transport or phagocytosis.
Answer:
Common characteristics of birds and fishes are:
They can have Respiration.
They can move from one place to another.
Ascaris is a type of parasitic nematode worm that inhabits the small intestine of its host, which includes humans. The intestine can be a harsh environment for biological material as it is alkaline and contains enzymes to facilitate the break down and absorption of nutrients. The presence of a <span>cuticle can act as a physical barrier, protecting the parasite from these elements.</span>
Answer:
The leukocytes are the main defenses of our body.
Explanation:
From the mother cell it will be a differentiation, from the mother cell to be a mother cell hematopoietic, this will turn into a lymphatic mother cell until it will be 3 different kinds of lymphocytes, the B, T and NK.
Lymphocyte B is the responsible for the inmune system based in antibodies and antigens, due to specific proteins.
Lymphocytes T, are the ones that come from the mother cell of the bone marrow. They are the responsible for the immunity against some illness like cancer.
Lymphocytes NK (natural killer) are the responsible for killing bad cells (like cancer cells) because they "eat" them in a phagocytosis process.
Answer:
the answer is false. Dieting usually leads to weight loss.
