Answer:
Due to environmental conditions.
Explanation:
With the passage of time, environmental conditions change which causes the evolution of of four legged land animals from fish like creature. This change occurs due to change in environment. In water, there is no need for legs because fish moves with the help of fins and tail but the organisms that lives on land has legs in order to move from one place to another so we can say that change in the physical structure of organism occurs due to environment.
 
        
             
        
        
        
Answer: incomplete dominance
Explanation:
Incomplete dominance is also referred to as partial dominance or semi dominance. It occurs when the two forms of gene in a trait combine in such a way that one does not have a dominance over the other one. Therefore, there's a blend of both genes in the physical appearance of such organism.
Therefore, a low pitched male voices (RR) and a high pitched male voice (rr). Heterozygotes have a baritone voice is an example of incomplete dominance.
 
        
             
        
        
        
The carbon model is the flow and the movement of the carbon and its compound in the atmosphere. Climate change is the limitation of the carbon model. 
<h3>What is climate change?</h3>
A climate change is a variation in the weather and the climate pattern due to a change in temperature and other atmospheric factors. It will lead to a transformation in the flow of carbon in the environment.
Increased carbon in surroundings increases temperature and results in a change in seasons and humidity levels, leading to changes in the rainfall. 
Therefore, climate change is the limitation of the carbon model.
Learn more about the carbon cycle here:
brainly.com/question/21984131
#SPJ1
 
        
             
        
        
        
Answer:

Explanation:
<h3><u>Given Data:</u></h3>
Wavelength = λ = 6.25 × 10⁷ m
Speed of light = c = 2.998 × 10⁸ m/s
<h3><u>Required:</u></h3>
Frequency = f = ?
<h3><u>Formula:</u></h3>

<h3><u>Solution:</u></h3>
Put the givens in the formula.
![\displaystyle f=\frac{2.998 \times 10^8}{6.25 \times 10^7} \\\\f=0.48 \times 10^1\\\\f=4.8 \ Hz\\\\\rule[225]{225}{2}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20f%3D%5Cfrac%7B2.998%20%5Ctimes%2010%5E8%7D%7B6.25%20%5Ctimes%2010%5E7%7D%20%5C%5C%5C%5Cf%3D0.48%20%5Ctimes%2010%5E1%5C%5C%5C%5Cf%3D4.8%20%5C%20Hz%5C%5C%5C%5C%5Crule%5B225%5D%7B225%7D%7B2%7D)