In the picture attached to this question, the two diagrams above did not show very well but I believe that the first diagram contain four dots, which means that the correct option is A.
Carbon has six electrons, that is why 6 is its atomic number is 6 . In writing electronic configuration, two electrons are usually placed in the most inner shell while the other shells will have 8 electrons each. In the case of carbon which has 6 electrons, only four will remain after 2 electron has been put in its inner shell. Therefore the number of electron in its outermost shell will be four.
Answer:
down
Explanation:
because gravity come from the center of the earth the gravitational pull, pulls us down.
<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:
In biology, a molecular clock can be described as a method to determine the time for the divergence of species which occurred by the process of evolution.
Explanation:
The mutation rates of different molecules are used in this method. The mutation rates for DNA sequences and amino acid sequences are usually considered. The molecular clock can be used to compare and estimate the splitting of a lineage. For example, by this method, one can interpret when the chimpanzees and humans diverged from each other.
Hope this helped!
-Toshino
Answer:
6==. During spermatogenesis, four sperm result from each primary spermatocyte, which divides into two haploid secondary spermatocytes; these cells will go through a second meiotic division to produce four spermatids
