<span>When an error occurs in dna duplicating itself it might be produce a beneficial mutation. This genetic variation might in itself be good because it gives it a better chance to survive in its natural environment. If this continues it will be more carried in general population because it increases the entity's ability to survive.</span>
Approximately 96% of the Earth's water is salt water in the oceans and seas. Therefore, only 4% of the Earth's water is fresh water.Groundwater is an important source of freshwater storage because <span> It is the only viable source of freshwater in some areas.
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</span></span>b. It is the only viable source of freshwater in some areas.
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28. <u>Answer</u>: All mutations do not affect the organisms due to the following reasons:-
1. The DNA consists of both coding and non coding regions. The coding regions are known as exons and non coding regions are called as introns. The <em>non coding regions </em>do not make up the protein. Thus, if the mutations occur in non coding regions they do not affect the organism.
2. There are some mutations that result in the change of the codon but the new codon formed codes for the same amino as the previous one. This is possible because of the degeneracy of genetic code. For eg, AAA codes for lysine, however if the mutation changes this code to AAU then this also codes for lysine. Such mutations are called as <em>silent</em> mutations.
3. There are some mutations which result in the change in amino acid however the new amino acid formed is similar to the previous one in its properties for e.g leucine and isoleucine. Such mutations are called as <em>neutral</em> mutations and they do not affect the organism
29. <u>Answer</u>: 1. The process of mitosis results in the formation of <em>two diploid cells</em> whereas meiosis results in the formation of <em>4 haploid cells.</em>
2. The process of mitosis takes place to produce copies of the <em>body cells </em>whereas the process of meiosis takes place to produce the <em>gametes</em>.
<u>Explanation</u>:-
- <u>Mitosis</u> is a process in which a cell undergoes a single round of division to produce two identical copies of itself . It occurs in 4 phases Prophase, metaphase, anaphase and telophase. This process occurs in the body cells.
- <u>Meiosis</u> is a process in which a cell undergoes two rounds of cell division to produce 4 copies of haploid cells from a single diploid cell. This process takes place for the formation of gametes.
29. <u>Answer</u>:
<em>Pros</em>
1. Genetic engineering helps us to tackle several diseases. There are many diseases which are caused due to genetic mutations. Genetic engineering helps us to rectify these mutations and hence combat such diseases.
2. Genetic engineering helps us to produce new foods which can withstand adverse conditions such as high/low temperatures, low rainfall, are disease and pest resistant etc. This, genetic engineering helps to significantly improve crop production.
<em>Cons</em>
1. Genetic engineering leads to a decrease in genetic diversity.
2. It can lead to a decrease in the nutritional value of food as genetic engineering often causes an accelerated growth of animals and hence, the nutritional valie of poultry foods is compromised.
A, electro magnetic is not a form of potentional energy
Answer:
9 normal : 3 striped : 3 spotted: 1 striped and spotted.
Explanation:
The F1 progeny contains no spots or stripes and are considered as normal, it means normal tail and normal head are dominant on their alternative traits. So, it means that the F1 progeny are heterozygous in nature for both of the traits.
The cross between 2 F1 progeny is dihybrid cross of lizards (heterozygous) which will produce offspring in 9:3:3:1 ratio, where 9 are normal, 3 striped which are dominant in the one character, 3 spotted which are dominant in other, and 1 will be stripped and spotted which is recessive in nature.
