Answer:
They are more attracted by the oxygen atom than by the hydrogen atom.
Explanation:
The bond between hydrogen and oxygen atoms in a water molecular is polar in nature. This is due to the differences in electronegativity of oxygen and hydrogen. Oxygen is much more electronegative than hydrogen.
The higher electronegativity of oxygen atom means that it attracts the electrons of the bond towards itself. Hence, the electrons of the bond between hydrogen and oxygen atoms in a water molecule are more attracted towards oxygen atom due to its higher electronegativity.
Answer:
The correct answer will be option B.
Explanation:
Plant cell shows distinguishing features from the animal cell which can be easily observed like:
1. Shape: Plant cell is usually rectangular while the animal cell is circular.
2. Membrane : Plant cell posses two layers- outer cell wall and inner plasma membrane while the animal cell only plasma membrane.
3. Vacuole: plant cell contains a single large vacuole whereas animal cell contains small vacuole if any.
4. Ribosomes: plant cell posses more free cytoplasmic ribosomes while animal cell contains more attached ribosomes.
On the basis of this, we can predict that James is preparing a plant cell with balloon shoeing large vacuole and marbles as ribosomes.
Thus, option B is the correct answer.
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.
When a human gets hot it sweats. That is maintaining a stable internal environment - homeostasis
