Answer:haemoglobin
Explanation:
Inside the air sacs, oxygen moves across paper-thin walls to tiny blood vessels called capillaries and into your blood. A protein called haemoglobin in the red blood cells then carries the oxygen around your body.
Answer:
b. pass through pores in the capillary endothelium
Explanation:
The fenestrated capillaries and sinusoids have pores in their endothelium. These pores or the intracellular clefts vary in size between the fenestrated capillaries and sinusoids. Sinusoids have larger intracellular clefts. The pores serve as a passage for the movement of water-soluble substances, proteins and other substances that cannot cross the hydrophobic interior of the cell membranes.
Water-soluble hormones also cannot pass through the capillary walls. Therefore, these hormones pass through the pore or the fenestrations present in the endothelium of capillaries.
B. they are single molecules...
Answer:
(2) exchange food, oxygen, and waste between
mother and fetus
Explanation:
In most mammals like humans, the fetus produced as a result of the fertilization of the sperm and egg, develops in the uterus or womb of the female. However, this developing fetus cannot yet fend for what it requires for survival and is still dependent on the mother e.g nutrients, oxygen etc. How do this substances get to the fetus? Here comes the role of the PLACENTA.
Placenta is an organ in the uterus that serves as a connection between the mother and the fetus in her womb. The placenta enables the mother to pass digested nutrients to the fetus and exchange gases (oxygen and Carbondioxide) between them via the umbilical cord. The placenta also enables the mother remove waste produced by the fetus into her bloodstream.
