Prokaryotes are the Earth`s firs living things. This are the simplest life forms exhibiting ( showing ) cellular structures.
They exist in 2 major forms:
- Eubacteria ( most of the common bacteria that are found everywhere ),
- Archaebacteria ( ancient bacteria that live in very extreme conditions ).
Answer: Prokaryotes.
Yes. There are seven billion people on the planet. There are four main eye color traits. What do you think?
<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.
<span>1.
</span>Cones perceive
light in color while rods perceive light in black and white.
<span>2.
</span>Rods can perceive dim light, unlike cones. The rods are located at the edges of the eyes. This is why it easier to perceive an image in the dark through
the corner of the eyes.
<span>3.
</span>The discs that compose the cones are usually
partially open to the surrounding vitreous
fluid while those of the rods are closed.
Plant cells are the only cells with a cell wall.
