- An object's kinetic energy depends on its mass and its speed.
- The faster something is moving and the heavier it is, the more work it can do.
- Kinetic energy increases as an object moves faster.
- If an objects speed is doubled > kinetic energy is quadrupled.
<em>If an object is not moving, it does not have kinetic energy. </em>
Answer:
Letter B - Electrolytes.
Explanation:
Nerve signal conduction and muscle contraction depend on electrolyte balance to occur.
Sodium, potassium, and chlorine, for example, are typical electrolytes found in the body that are present in the nerve impulse due to the process of cellular depolarization.
Basically, for the conduction of the nerve signal to happen, it must happen the depolarization of nerve cells that control muscle contraction and in this process, there is mainly sodium and potassium change, while for actin-myosin system activation and finally muscle contraction, We mainly need calcium.
So, in general, an electrolyte balance is required during both processes.
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.
Question is incomplete. Complete question is as follows:
The ____ abuts the lumen of the alimentary canal and consists of epithelium, lamina propria, and muscularis mucosae.
Answer:
Mucosa
Explanation:
Mucosa or mucosal membrane forms the lining of many cavities in the body like the alimentary canal and also covers many internal organs. It lines reproductive, digestive and respiratory system. In the gastrointestinal tract the mucosa is made of three layers: epithelium, lamina propria and muscularis mucosae.
The epithelium of mucosa is made of simple columnar epithelium cells. It consists of many types of cells like parietal cells (secrete HCL) and foveolar cells (secrete mucus). Lamina propria is a loose connective tissue present beneath the epithelium. It provides nutrition and support to epithelium. Muscularis mucosae has smooth muscle fibers which helps the glands on the surface to secrete their contents and also increase the contact between contents of lumen and epithelium.
In both cases the electron transport chain<span> uses the energy to pump hydrogen ions across a membrane</span>
