Protein-energy malnutrition is a form of undernutrition caused by an extremely deficient intake of calories, protein, or both. Two examples of this type of malnutrition are kwashiokor and marasmus. Protein-energy malnutrition is more often caused by decreased absorption or abnormal metabolism. It is defined as a range of pathological conditions arising from coincident lack of protein and/or energy in varying proportions. The condition vary in forms ranging from mild through moderate to severe degrees.
<u>Answer:</u>
Recent evidence suggest that feathers evolved from scales and suggest that 'feathers and pycnofibers' could be homologous.
<u>Explanation:</u>
- One of the major difficult issue related to bird evolution is the evolution of feathers.
- Feathers are considered as the most 'complex integumentary structures' which are found in vertebrates.
- Evolutionary developmental biology suggests that the 'planar scale structure' is been modified for developing into feathers by 'splitting' to form web like structures.
- Scales and Feathers consist of 'two distinct form of keratin' so it was thought that 'each type was exclusive skin structure' but recent study suggests that they are developmental expressions of same skin structures.
D, this competition effects death rates, birth rates hence effecting growth rates, in A less dense area competition would be low increasing birth rates and growth rates while decreasing death
The type of ecological succession being described in the illustration is primary succession.
<h3>What is primary succession?</h3>
It is a form of succession that occurs when an area that has never been occupied by any living organism becomes exposed and eventually gets colonized by living organisms.
It is quite different from secondary succession which happens when an area that has been housing biotic communities before gets disrupted by a major disturbance.
A new island formed by volcanic action has never housed any biotic community before. Thus, only primary succession can occur there.
More on primary succession can be found here: brainly.com/question/26675203
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