The aspect of chromosome behavior that most clearly accounts for Mendel's Law of Independent Assortment is the replication of chromosomes. The replication occurs before meiosis. As a result, the alleles of one gene can be sorted into gametes and are independent of the alleles of other genes.
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.
Answer: They are sterile
Explanation:
Mule is a hybrid of male donkey and female horse with different chromosome number and is considered superior to both horse and donkey. Still it is considered as a weak hybrid this is because the mule is sterile which means that it cannot reproduce further.
The mule though is superior in many ways such as it can jump and is strong. The hybrid of mule is not good as it cannot continue its next generations on earth.
They are sterile and so is a weak hybrid.
Answer:
ham Bhan k Uthai xeya ta hamra Garmin lagai xa kathi la Kani k bara ma Pharo thanda lagai xai
Answer:
D. four haploid cells
Explanation:
When meiosis is complete,four haploid cells are formed from a single diploid cell. The four daughter cells produced that contains half the number of chromosome than that of their parent cell. Due to meiosis the number of chromosomes remain fixed in a species from generation to generation.
The process results in four daughter cells that are haploid, which means they contain half the number of chromosomes of the diploid parent cell. Meiosis has both similarities to and differences from mitosis, which is a cell division process in which a parent cell produces two identical daughter cells.
