Answer and explanation:
2. The specialized human cells in the image correspond to a white adipocyte - fat cell - and an erythrocyte or red blood cell.
How are these cells specialized?
- White adipocyte contains a large amount of fat - within the globule - which occupies almost all of its cytoplasm, formed by triglycerides and cholesterol esters.
- Red blood cell is not strictly speaking a cell, as it lacks a nucleus, but its circular shape allows it to travel easily in the circulatory system, as well as containing haemoglobin, a molecule that allows it its main function.
What is its function?
- The adipocyte is the cell that forms part of the fatty tissue, whose function is protective - insulating and cushioning - as well as being the body's energy reserve.
- The red blood cell contains hemoglobin, a molecule that allows it to fix gases - oxygen and carbon dioxide - to be transported in the blood.
3. A boy's mass was measured from birth to his first birthday, and the graph shows that it remains at a low percentile, indicating a low mass (weight) for his age.
a. At 3 months of age, a baby's mass is at the 25th percentile, indicating - compared to other 3-month-old babies - that his mass is lower than most, which may be interpreted as a health problem or lack of adequate nutrition.
With respect to body mass, the 25th percentile represents that this measurable characteristic is low and rare.
b. Suggest how old the boy was when the doctor became concerned about his growth.
According to the chart, the doctor began to worry about the baby's growth from the age of 6 months, when the baby's body mass began to decrease, rather than increase.
In an infant, it is normal to see a progressive increase in height and weight with age, a marker of adequate growth, development and nutrition. The doctor is concerned that not only has the baby had a low mass from birth, but also that the mass begins to decrease after a certain age, maybe related to severe nutritional or physiological problems.