<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.
Answer:
D. DDT
Explanation:
DDT is highly persistent in the environment means that it break down very slowly in the environment. The half-life for DDT is from 2 to 15 years. Half-life is the time needed for the degradation of half of the compound. Persistent bio-accumulative toxic substances (PBTs) are chemicals that break down slowly in the environment and its accumulation in living organisms are toxic. Some PBTs are dispersed through air currents while some uses other environmental pathways, resulting in contamination of regions far from their points of origin.
Answer:
The theory of evolution was proposed by Charles Darwin and was first formulated in his book, "Origin of Species" in 1859. It focuses on the changes in species and populations over time
Answer:
A. damaged her peripheral nervous system because the information regarding taste cannot be transmitted back to her brain.
Explanation:
The nervous system is an important system of our body and is directly related to our survival. This system is linked to the coordination of the organism's various activities and is also responsible for allowing the interpretation of the environment around us.
The nervous system is an important system of our body and allows us to have emotions, to remember an important moment in our lives, to interpret smells, tastes and images, to make movements and even to stay alive through the automatic breathing and heartbeat.
Taste, that is, the sense of taste is directly linked to the peripheral nervous system. For this reason, if Stacey has lost her sense of taste, we can conclude that she has damaged her peripheral nervous system because taste information cannot be transmitted back to her brain.
Answer:
nuclear membrane, endoplasmic reticulum, Golgi apparatus, and vesicle
Explanation:
The structures or organelles in internal membrane system in the cell do all production, processing and secretion function together. A prokaryotic cell does not contain any membrane bound organelles but Eukaryotic cells do have. Nuclear membrane has double membrane and golgi-rendoplasmic reticulum and vesicle contain single membrane so all these organelles are membrane bounded.
