Answer:
In the entire solar system, the environment of planet earth is unique due to the presence of the atmosphere.
It is responsible for providing carbon dioxide and oxygen which are essential for the presence of life on earth.
Secondly, it helps in keeping the earth warm through the greenhouse effect.
It prevents the entry of harmful radiations of the sun into the atmosphere.
Answer:
frequency of the blue (B) allele 
frequency of the red (R) allele 
The number of blue plants expected is 
The number of red plants expected is 
The anticipated number of violet plants is 
Calculated chi square value
Explanation:
Frequency of blue allele is
Frequency of blue allele is equal to sum of frequency of BB and half of frequency of BR

Frequency of other allele

Chi Square test
See the attached file
The number of blue plants expected is 
The number of red plants expected is 
The anticipated number of violet plants is 
Calculated chi square value
The most common organisms with exoskeletons are arthropods which include insects (bees, ants), arachnids (spiders) and crustaceans (lobsters and crabs).
In cardiac muscle
a. an action potential spreads throughout the Z discs.
b. intercalated discs connect the muscle fibers together.
c. calcium enters the cell from storage chambers called intercalated discs.
d. potassium is released from the sarcoplasmic reticulum
Answer:
b. intercalated discs connect the muscle fibers together.
Explanation:
Intercalated discs are components of the muscles found in the heart(cardiac muscles).
Intercalated discs join the cardiomyoctes (muscle cells or fibers) together so that they can function as one and transmit signals amongst themselves during the contraction of the heart.
Intercalated discs are made of up desmosomes and gap junctions.
Intercalated discs are found on the lining of the sacromere and can only be seen by using a microscope to observe the longitudinal section of the heart tissue.
Answer: The correct answer is- all the sugar maple trees that are present in a state park.
Population can be described as a group of individuals belonging to a particular species, which inhabit a particular area.
In this question, last option that is all the sugar maple trees that are present in a state park correspond to a particular population.
Other options have organisms occupying different areas across the world.