Chapter 7 Part 4: Evolution

<div style='text-align : center'>
<Success><font size="5"><b>Evolution</b></font></Success>
</div>
<h4 id="primaryshort-answer-type-questionsprimary-10"><Primary>Short Answer Type Questions</Primary></h4>
<hr>
<div class="text-container">
<p><strong>Ans.</strong> The movement of individuals from one place to another is called <strong>migration</strong>.</p>
<ul>
<li>It can be the movement of individuals to a different populations (i.e., emigration) or movement of individual into a particular population (i.e., cmmigration) Migration may bring in more such alleles, that bestow upon the individuals, such adaptations or traits which are selected by nature.</li>
<li>Thus, enhancing the effect of selection.</li>
</ul>
<p><Success>Ans. to be continued</Success></p>
</font>
</div>
<hr>
<font size ="4">
<div style='text-align : center'>
Multiple choice questions (MCQs) $\rightarrow$ <span style="color:blue">Very short answer type questions</span> $\rightarrow$ Short answer type questions $\rightarrow$ Long answer type questions
</div>
</font>

<div style='text-align : center'>
<Success><font size="5"><b>Evolution</b></font></Success>
</div>
<h4 id="primarylong-answer-type-questionsprimary-3"><Primary>Long Answer Type Questions</Primary></h4>
<hr>
<div class="text-container">
<ul>
<li>Five factors that influence these values are</li>
</ul>
<p>(i) <strong>Gene Migration or Gene Flow</strong> When migration of a section of population to another place occurs, gene frequencies change in the original as well as in the new population.</p>
<ul>
<li>New genes/alleles are added to the new population and these are lost from the old population.</li>
<li>There would be gene flow if this gene migration, happens multiple times.</li>
</ul>
<p><Success>Ans. to be continued</Success></p>
</font>
</div>
<hr>
<font size ="4">
<div style='text-align : center'>
Multiple choice questions (MCQs) $\rightarrow$ Very short answer type questions $\rightarrow$ Short answer type questions $\rightarrow$ <span style="color:blue">Long answer type questions</span>
</div>
</font>

<div style='text-align : center'>
<Success><font size="5"><b>Evolution</b></font></Success>
</div>
<h4 id="primarylong-answer-type-questionsprimary-8"><Primary>Long Answer Type Questions</Primary></h4>
<hr>
<div class="text-container">
<p><strong>Ans.</strong> <strong>Divergent evolution</strong> is the evolution of a number of different forms of animals or plants froms of a common ancestral form.</p>
<ul>
<li>The driving force behind, it is adaptations to newly involved habitat and the prevailing environmental conditions there.</li>
<li>As the original population increases in size, it spreads out from its centre of origin to exploit new habitas and food resources.</li>
</ul>
<p><Success>Ans. to be continued</Success></p>
</font>
</div>
<hr>
<font size ="4">
<div style='text-align : center'>
Multiple choice questions (MCQs) $\rightarrow$ Very short answer type questions $\rightarrow$ Short answer type questions $\rightarrow$ <span style="color:blue">Long answer type questions</span>
</div>
</font>

<div style='text-align : center'>
<Success><font size="5"><b>Evolution</b></font></Success>
</div>
<h4 id="primarylong-answer-type-questionsprimary-10"><Primary>Long Answer Type Questions</Primary></h4>
<hr>
<div class="text-container">
<font size ="6">
<ul>
<li>
<p>A good example of this process is the evolution of the Australian marsupials into species adapted as carnivores, herbivores, burrowers, fliers, etc.</p>
</li>
<li>
<p>Another example is that of peritadactyl limb in mammals.</p>
</li>
<li>
<p>The flipper of a seal, wing of a bat, forelimb of a male, front legs of horse and the arm of a man perform different functions, but exhibit the same structural plan including same pentadactyl pattern of bones.</p>
</li>
</ul>
</font>
</div>
<hr>
<font size ="4">
<div style='text-align : center'>
Multiple choice questions (MCQs) $\rightarrow$ Very short answer type questions $\rightarrow$ Short answer type questions $\rightarrow$ <span style="color:blue">Long answer type questions</span>
</div>
</font>

<div style='text-align : center'>
<Success><font size="5"><b>Evolution</b></font></Success>
</div>
<h4 id="primarylong-answer-type-questionsprimary-15"><Primary>Long Answer Type Questions</Primary></h4>
<hr>
<div class="text-container">
<font size ="6">
<ul>
<li>
<p>However, the black variants were camouflaged better on soot covered barks and their number increased drastically.</p>
</li>
<li>
<p>If the industries were removed, the population of black moths would have declined because as stated before, they would not be able to camouflage against a light background (no black soot).</p>
</li>
<li>
<p>Also the growth of lichens would increase.</p>
</li>
<li>
<p>Therefore, the dark variants would be spotted better by predators and be eaten more frequently.</p>
</li>
</ul>
</font>
</div>
<hr>
<font size ="4">
<div style='text-align : center'>
Multiple choice questions (MCQs) $\rightarrow$ Very short answer type questions $\rightarrow$ Short answer type questions $\rightarrow$ <span style="color:blue">Long answer type questions</span>
</div>
</font>

<div style='text-align : center'>
<Success><font size="5"><b>Evolution</b></font></Success>
</div>
<h4 id="primarylong-answer-type-questionsprimary-18"><Primary>Long Answer Type Questions</Primary></h4>
<hr>
<div class="text-container">
<p>(ii) <strong>Struggle for Existence</strong> Individuals multiply in geometric ratio, whereas space and food remain almost limited.</p>
<p>(iii) <strong>Variations</strong> Members of a population vary is size, form and other characteristics even though they look superficially similar, no two individuals are alike.</p>
<ul>
<li>These variations are gradual and those with adaptive value are passed on to next generation.</li>
</ul>
<p><Success>Ans. to be continued</Success></p>
</font>
</div>
<hr>
<font size ="4">
<div style='text-align : center'>
Multiple choice questions (MCQs) $\rightarrow$ Very short answer type questions $\rightarrow$ Short answer type questions $\rightarrow$ <span style="color:blue">Long answer type questions</span>
</div>
</font>

<div style='text-align : center'>
<Success><font size="5"><b>Evolution</b></font></Success>
</div>
<h4 id="primarylong-answer-type-questionsprimary-19"><Primary>Long Answer Type Questions</Primary></h4>
<hr>
<div class="text-container">
<font size ="6">
<p>(iv) <strong>Survival of the Fittest and Natural Selection</strong> During struggle for existence only those individuals could survive which exhibit beneficial variations and adapt better to changing environment.</p>
<ul>
<li>This is known as natural selection.</li>
</ul>
<p>(v) <strong>Origin of Species</strong> Natural Selection results in modification of traits within a lineage, which over a period of long time can bring about evolution of original species into new one.</p>
</font>
</div>
<hr>
<font size ="4">
<div style='text-align : center'>
Multiple choice questions (MCQs) $\rightarrow$ Very short answer type questions $\rightarrow$ Short answer type questions $\rightarrow$ <span style="color:blue">Long answer type questions</span>
</div>
</font>

<div style='text-align : center'>
<Success><font size="5"><b>Evolution</b></font></Success>
</div>
<h4 id="primarylong-answer-type-questionsprimary-21"><Primary>Long Answer Type Questions</Primary></h4>
<hr>
<div class="text-container">
<p><strong>Ans.</strong> This phenomenon indicated in the question is convergent evolution where by organisms, not closely related, evolve similar traits independently as a result of adaptation to similar environment e.g.,</p>
<p>(i) Streamlined shape of sharks and dolphins.</p>
<ul>
<li>The former is a fish, while dolphin is a mammal, but both of them depend on swift movement through the water, so a streamlined shape is essential.</li>
</ul>
<p><Success>Ans. to be continued</Success></p>
</font>
</div>
<hr>
<font size ="4">
<div style='text-align : center'>
Multiple choice questions (MCQs) $\rightarrow$ Very short answer type questions $\rightarrow$ Short answer type questions $\rightarrow$ <span style="color:blue">Long answer type questions</span>
</div>
</font>