Answer:
<u>the bottleneck effect</u>
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Explanation:
Genetic drift has an important impact on the small populations. mutations, which are spontaneous heritable changes in the genetic code, made up of DNA. Here, mutations accumulate over time in a group, modifying the distribution of alleles or various forms of a gene. Natural selection may result in a loss of diversity in a population called genetic drift; one trait's allelic frequency rises while others become less prevalent. Typically such differences exist because of occurrences of mutation and recombination.
Some mutations or alleles may become extinct from the population.
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Variants of a gene accumulate and are transmitted across generations; the frequencies of these occurrences are altered and become more stable in genetic drift- they become genetically distinct and may eventually form a new species after isolation. This may be further compounded through other  phenomena such as the founder effect where a group separates and genetic diversity decreases; and the bottleneck effect where barriers to reproduction or the die-off a population increases genetic drift. 
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(4) organisms in a changing environment must adapt to acquire necessary traits and survive
        
                    
             
        
        
        
Answer: 3.friction
Explanation: friction is a force of resistance acting between objects in contact and tending to dampen their motion
 
        
                    
             
        
        
        
Answer:
cnidaria
Explanation:
the group contains jellyfish which fit that exact description tentacles that sting you with a burning sensation if your skin comes in contact with them
 
        
             
        
        
        
The answer is sexual reproduction in which the creation of offspring by fertilization consisting 2 haploid gametes come together to form a diploid zygote with a new genetic combination. The main difference between sexual and asexual reproduction is that asexual reproduction results in a genetically identical offspring whereas sexual reproduction results in a unique offspring in which offspring with a new genetic combination.