Answer:
CAT - GGC - TAC mutates to CAT - GGC - TAG
Explanation:
Changes occur in the nucleotide sequence of the DNA molecule. These changes referred to as MUTATION are usually due mistakes during DNA replication or induced by mutagens (mutation-causing substances). Mutation can be of different types depending on the kind of change that occured to the nucleotide sequence. Based on this question, one of the mutation types is SUBSTITUTION MUTATION.
Substitution mutation is a kind of mutation in which one or more nucleotide base replaces another in the sequence. 
The option that suits an example of substitution mutation is: CAT - GGC - TAC mutates to CAT - GGC - TAG because Guanine nucleotide replaces Cytosine nucleotide in the third CODON i.e. TAC becomes TAG.
 
        
                    
             
        
        
        
Pollution from a near by city is your answer ;D
        
             
        
        
        
The right option is; D) mitosis
In multicellular organisms, life begins as a single cell until mitosis occurs, causing growth.
Mitosis is a process of cell division, and a part of the cell cycle in which a single cell divides, and produces two identical daughter cells (new nuclei) that contains the same shares of the parent’s cell part. Mitosis occurs in multi cellular organisms, and its primary purpose is for growth, and to replace worn out cells. Mitosis contains four basic stages which are; prophase, metaphase, anaphase, and telophase.  
 
        
                    
             
        
        
        
No,not all organs are weighed on a triple beam balance.
<u>Explanation:</u>
- Usually smaller sized organs like adrenals, thyroid are commonly used to be weighed on triple beam balance, whereas larger organs like lungs, liver and heart can only be weighed on grocer's scale.
- Only weight of the smaller body organs can be measured very precisely with the help of triple beam balance, where as if we measure the weight of the larger organs using the same triple beam balance,then the resultant value thus obtained will not be accurate enough.
- Hence organs are weighed on a triple beam balance.
 
        
             
        
        
        
Answer:
attatch the images of the Petri dishes so we can further help in understanding this question