Nemathelminthes
Nemathelminthes is composed of two words i.e. nematoswhich means thread and helminthes which means worm. This note includes information about general characterstics and classification of phylum nemathelminthes.
Summary
Nemathelminthes is composed of two words i.e. nematoswhich means thread and helminthes which means worm. This note includes information about general characterstics and classification of phylum nemathelminthes.
Things to Remember
- Nemathelminthes is composed of two words i.e. nematoswhich means thread and helminthes which means worm.
- They are cylindrical, elongated, unsegmented and worm like.
- They are mostly parasitic and some are free living found in soil and water.
- Body is covered with thick non living cuticle.
- Fertilization is internal.
- Development may be direct or indirect with some larval stages.
- Body has not distinct head.
- Development may be direct or indirect with some larval stages.
MCQs
No MCQs found.
Subjective Questions
Q1:
Find the Quartiles of the list:
30, 35, 25, 16, 12, 8, 10.
Type: Short Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Arranging the data in ascending order.</p> <p>8, 10, 12, 16, 25, 30, 35.</p> <p>N=7</p> <p>Now, Position of Q<sub>1</sub>= (\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p>= (\(\frac{7+1}{4}\))<sup>th</sup> item.</p> <p>= 2<sup>th</sup> item.</p> <p>In given data 2<sup>th</sup> item is 10.</p> <p>Therefore, Q<sub>1</sub> =10.</p>
Q2:
Find the Quartile(Q1) of the list:
16, 10, 12, 18, 20, 14, 30, 28, 40.
Type: Short Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Arranging, the data in ascending order.</p> <p>10, 12, 16, 18, 20, 24, 28, 30, 40.</p> <p>N=9</p> <p>Now, Position of Q<sub>1</sub> = (\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p>= (\(\frac{9+1}{4}\))<sup>th</sup> item.</p> <p>= (\(\frac{10}{4}\))<sup>th</sup> item</p> <p>= 2.5<sup>th</sup> item.</p> <p>Then, 2.5<sup>th</sup> item lies in 2<sup>nd</sup> and 3<sup>rd</sup> item.</p> <p>so, Q<sub>1</sub>Median = \(\frac{12+16}{2}\)</p> <p>= \(\frac{28}{2}\)</p> <p>Therefore, Q<sub>1</sub>= 14.</p> <p></p>
Q3:
Find the Quartile(Q1) of the list:
12, 10, 16, 14, 20, 17, 23.
Type: Short Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Arranging the data in ascending order.</p> <p>Now, 10, 12, 14, 16, 17, 20, 23.</p> <p>N=7</p> <p>Q<sub>1</sub> = (\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p> = (\(\frac{7+1}{4}\))<sup>th</sup> item</p> <p> = 2<sup>th</sup> item.</p> <p>2<sup>th</sup> item lies in 12.</p> <p>Therefore, Q<sub>1</sub> = 12.</p>
Q4:
Find the Quartile(Q3) of the list:
15, 9, 27, 21, 39, 33, 45.
Type: Short Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Arranging the data in ascending order.</p> <p>9, 15, 21, 27, 33, 39, 45.</p> <p>N=7</p> <p>Now, Q<sub>3</sub> =3(\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p>= 3(\(\frac{7+1}{4}\))<sup>th</sup> item.</p> <p>= 3\(\times\)2<sup>th</sup> item</p> <p>= 6<sup>th</sup> item.</p> <p>In given data 6<sup>th</sup> item is 39.</p> <p>Therefore, Q<sub>3</sub> = 39.</p>
Q5:
Find the Quartile(Q3) of the list:
26, 14, 22, 18, 38, 30, 34.
Type: Short Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Arranging the data in ascending order.</p> <p>14, 18, 22, 26, 30, 34, 38.</p> <p>N= 7</p> <p>Now, Q<sub>3</sub> = 3(\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p> = 3(\(\frac{7+1}{4}\))<sup>th</sup> item</p> <p> = 3\(\times\)2</p> <p> = 6<sup>th</sup> item.</p> <p>In the given data 6<sup>th</sup> item is 34.</p> <p>Therefore, Q<sub>3</sub>= 34.</p>
Q6:
Find the Quartile(Q3) of the list:
80, 90, 60, 70, 20, 30, 50, .
Type: Short Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Arranging the data in ascending order.</p> <p>20, 30, 50, 60, 70, 80, 90.</p> <p>N= 7</p> <p>Now, Q<sub>3</sub> = 3(\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p> = 3(\(\frac{7+1}{4}\))<sup>th</sup> item</p> <p> = 3\(\times\)2</p> <p> = 6<sup>th</sup> item.</p> <p>In given data 6<sup>th</sup> item is 80.</p> <p>Therefore, Q<sub>3</sub> = 80.</p>
Q7:
Find the Quartile(Q1) of the list:
| Marks(x) | 32 | 36 | 40 | 44 | 48 | 52 |
| No of students(f) | 2 | 5 | 9 | 6 | 3 | 2 |
Type: Long Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Here,</p> <table width="320"><tbody><tr><td>Marks(x)</td> <td>No of Students(f)</td> <td>c.f</td> </tr><tr><td>32</td> <td>2</td> <td>2</td> </tr><tr><td>36</td> <td>5</td> <td>2+5=7</td> </tr><tr><td>40</td> <td>9</td> <td>7+9=16</td> </tr><tr><td>44</td> <td>6</td> <td>16+6=22</td> </tr><tr><td>48</td> <td>3</td> <td>22+3=25</td> </tr><tr><td>52</td> <td>2</td> <td>25+2=27</td> </tr><tr><td>Total</td> <td>N=27</td> <td></td> </tr></tbody></table><p>Now, Q<sub>1</sub> = (\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p>=(\(\frac{27+1}{4}\))<sup>th</sup> item.</p> <p>= 7<sup>th</sup> item.</p> <p>In c.f Column, the corresponding value of 7 is 36.</p> <p>Therefore, Q<sub>1</sub> = 36</p>
Q8:
Find the Quartile(Q3) of the list:
| Marks | 50 | 60 | 70 | 80 | 90 | 100 |
| No of workers | 6 | 10 | 15 | 13 | 8 | 3 |
Type: Long Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Here,</p> <table width="301"><tbody><tr><td>Marks(x)</td> <td>No of workers(f)</td> <td>c.f</td> </tr><tr><td>50</td> <td>6</td> <td>6</td> </tr><tr><td>60</td> <td>10</td> <td>16</td> </tr><tr><td>70</td> <td>15</td> <td>31</td> </tr><tr><td>80</td> <td>13</td> <td>44</td> </tr><tr><td>90</td> <td>8</td> <td>52</td> </tr><tr><td>100</td> <td>3</td> <td>55</td> </tr><tr><td>Total</td> <td>N=55</td> <td></td> </tr></tbody></table><p>Now, Position of Q<sub>3</sub> = 3(\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p>= 3(\(\frac{55+1}{4}\))<sup>th</sup> item.</p> <p>= (\(\frac{168}{4}\))<sup>th</sup> item.</p> <p>= 42<sup>th</sup> item.</p> <p>In the given data, 42<sup>th</sup> item is 80.</p> <p>Therefore, Q<sub>3</sub> = 80</p>
Q9:
Find the Quartile(Q1) of the list:
| Marks(x) | 22 | 27 | 32 | 37 | 42 |
| No of people(f) | 35 | 42 | 40 | 30 | 24 |
Type: Long Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <table width="274"><tbody><tr><td>Marks(x)</td> <td>No of people(f)</td> <td>c.f)</td> </tr><tr><td>22</td> <td>35</td> <td>35</td> </tr><tr><td>27</td> <td>42</td> <td>77</td> </tr><tr><td>32</td> <td>40</td> <td>117</td> </tr><tr><td>37</td> <td>30</td> <td>147</td> </tr><tr><td>42</td> <td>24</td> <td>171</td> </tr><tr><td>Total</td> <td>N=171</td> <td></td> </tr></tbody></table><p>Now, Q<sub>1</sub> = (\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p>= (\(\frac{171+1}{4}\))<sup>th</sup> item.</p> <p>= 43<sup>th</sup> item.</p> <p>In c.f column, 43<sup>th</sup> item is just greater than 35.So, Q<sub>1</sub>lies on the correspondent value of 77.</p> <p>Therefore, Q<sub>1</sub> = 27</p> <p></p>
Q10:
Find the Quartile(Q1) of the list:
| Marks | 25 | 30 | 35 | 40 | 45 | 50 | 55 | 60 |
| No of students | 2 | 3 | 6 | 10 | 12 | 13 | 3 | 4 |
Type: Long Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Here,</p> <table width="266"><tbody><tr><td>Marks(x)</td> <td>Number of Students(f)</td> <td>C.f</td> </tr><tr><td>25</td> <td>2</td> <td>2</td> </tr><tr><td>30</td> <td>3</td> <td>2+3=5</td> </tr><tr><td>35</td> <td>6</td> <td>5+6=11</td> </tr><tr><td>40</td> <td>10</td> <td>11+10=21</td> </tr><tr><td>45</td> <td>12</td> <td>21+12=33</td> </tr><tr><td>50</td> <td>13</td> <td>33+13=46</td> </tr><tr><td>55</td> <td>3</td> <td>46+3=49</td> </tr><tr><td>60</td> <td>4</td> <td>49+4=53</td> </tr><tr><td>Total</td> <td>N= 53</td> <td></td> </tr></tbody></table><p>N= 53</p> <p>Now, Position of Q<sub>1</sub>=(\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p>= (\(\frac{53+1}{4}\))<sup>th</sup> item.</p> <p>= 13.5<sup>th</sup> item.</p> <p>In the given data, 13.5<sup>th</sup> item lies in 35 and 40.</p> <p>Now, 35+(40-35)\(\times\) 25%</p> <p>= 35+5\(\times\)\(\frac{25}{100}\)</p> <p>= 35 + 5\(\times\)0.25</p> <p>= 35+1.25</p> <p>= 36.25</p> <p>Therefore, Q<sub>1</sub>= 36.25</p>
Q11:
Find the Quartile(Q3) of the list:
| x | 100 | 200 | 300 | 400 | 500 | 600 | 700 |
| f | 8 | 9 | 7 | 15 | 22 | 12 | 10 |
Type: Long Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Here,</p> <table width="232"><tbody><tr><td> x</td> <td> f</td> <td> c.f</td> </tr><tr><td> 100</td> <td> 8</td> <td> 8</td> </tr><tr><td> 200</td> <td> 9</td> <td>8+9=17</td> </tr><tr><td> 300</td> <td> 7</td> <td>17+7=24</td> </tr><tr><td> 400</td> <td> 15</td> <td>24+15=39</td> </tr><tr><td> 500</td> <td> 22</td> <td>39+22=61</td> </tr><tr><td> 600</td> <td> 12</td> <td>61+12=73</td> </tr><tr><td> 700</td> <td> 10</td> <td>73+10=83</td> </tr><tr><td> Total</td> <td>N=83</td> <td></td> </tr></tbody></table><p>N=83</p> <p>Now, Q<sub>3</sub> = 3(\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p> = 3(\(\frac{83+1}{4}\))<sup>th</sup> item.</p> <p> = 3\(\times\)21</p> <p> = 63<sup>th</sup> item.</p> <p>In the given data, 63<sup>th</sup> item lies in 600.</p> <p>Therefore, Q<sub>3</sub> = 600.</p> <p></p>
Q12:
Find the Quartile(Q1) of the list:
27, 29, 18, 25, 32, 21, 26.
Type: Short Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Arranging the data in ascending order.</p> <p>27, 29, 18, 25, 32, 21, 26.</p> <p>N= 7</p> <p>Now, Q<sub>1</sub>= (\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p> =( \(\frac{7+1}{4}\))<sup>th</sup> item</p> <p> = \(\frac{8}{4}\)<sup>th</sup> item.</p> <p> = 2<sup>th</sup> item.</p> <p>Therefore, 2<sup>th</sup> item is 29.</p>
Q13:
Find the Quartile(Q1) of the list:
27, 29, 18, 25, 32, 21, 26.
Type: Short Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Arranging the data in ascending order.</p> <p>18, 21, 25, 26, 27, 29, 32</p> <p>N= 7</p> <p>Now, Q<sub>1</sub>= (\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p> =( \(\frac{7+1}{4}\))<sup>th</sup> item</p> <p> = \(\frac{8}{4}\)<sup>th</sup> item.</p> <p> = 2<sup>th</sup> item.</p> <p>Therefore, 2<sup>th</sup> item is 21.</p>
Q14:
Find the Quartile(Q3) of the list:
45, 32, 67, 54, 34, 28, 78,.
Type: Short Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Arranging the data in ascending order.</p> <p>28, 32, 34, 45, 54, 60, 67,</p> <p>N=7</p> <p>Now, Q<sub>3</sub> = 3(\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p> = 3(\(\frac{7+1}{4}\))<sup>th</sup> item.</p> <p> = 3\(\times\)2</p> <p> = 6<sup>th</sup> item.</p> <p>In the given data 6<sup>th</sup> item is 60.</p> <p>Therefore, Q<sub>3</sub> = 60.</p> <p><sup></sup></p>
Q15:
Find the Quartile(Q1) of the list:
10, 8, 6, 4, 12, 18, 20.
Type: Short Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Arranging the data in ascending order.</p> <p>4, 6, 8, 10, 12, 18, 20.</p> <p>N=7</p> <p>Now, Q<sub>1</sub> = (\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p> = (\(\frac{7+1}{4}\))<sup>th</sup>item.</p> <p> = \(\frac{8}{4}\)<sup>th</sup> item.</p> <p> = 2<sup>nd</sup>item.</p> <p>In the given data, 2<sup>nd</sup> item is 6.</p> <p>Therefore, Q<sub>1</sub> = 6.</p>
Q16:
Find the Quartile(Q3) of the list:
| Age | 8 | 10 | 12 | 14 | 16 | 18 |
| Number of Students | 3 | 5 | 7 | 8 | 3 | 1 |
Type: Short Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Here,</p> <table width="302"><tbody><tr><td>Years(x)</td> <td>Number of Students(f)</td> <td>c.f</td> </tr><tr><td>8</td> <td>3</td> <td>3</td> </tr><tr><td>10</td> <td>5</td> <td>3+5=8</td> </tr><tr><td>12</td> <td>7</td> <td>8+7=15</td> </tr><tr><td>14</td> <td>8</td> <td>15+8=23</td> </tr><tr><td>16</td> <td>3</td> <td>23+3=26</td> </tr><tr><td>18</td> <td>1</td> <td>26+1=27</td> </tr><tr><td>Total</td> <td>N= 27</td> <td></td> </tr></tbody></table><p>Here, N=27</p> <p>Now, Q<sub>3</sub> = 3(\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p>= 3(\(\frac{27+1}{4}\))<sup>th</sup> item.<br><br></p> <p>= 3\(\times\)7</p> <p>= 21<sup>st</sup>item.</p> <p>In the given data 21item lies in 14 years.<sup>st</sup>item lies in 14 years.</p> <p>Therefore, Q<sub>3</sub> = 14</p> <p></p>
Q17:
Find the Quartile(Q1) of the list:
| Wages | 45 | 55 | 65 | 75 | 85 | 95 |
| No of workers | 20 | 25 | 24 | 18 | 15 | 17 |
Type: Long Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Here,</p> <table width="243"><tbody><tr><td>Wages(x)</td> <td>No of workers(f)</td> <td>c.f</td> </tr><tr><td>45</td> <td>20</td> <td>20</td> </tr><tr><td>55</td> <td>25</td> <td>45</td> </tr><tr><td>65</td> <td>24</td> <td>69</td> </tr><tr><td>75</td> <td>18</td> <td>87</td> </tr><tr><td>85</td> <td>15</td> <td>102</td> </tr><tr><td>95</td> <td>17</td> <td>119</td> </tr><tr><td>Total</td> <td>N= 119</td> <td></td> </tr><tr><td></td> <td></td> <td></td> </tr></tbody></table><p>N=119</p> <p>Now, position of Q<sub>1</sub> = (\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p>= (\(\frac{119+1}{4}\))<sup>th</sup> item.</p> <p>= \(\frac{120}{4}\)</p> <p>= 30<sup>th</sup> item.</p> <p>In the given data, 30<sup>th</sup> item lies in 45 c.f.</p> <p>Therefore, Q<sub>1</sub>= 55</p>
Q18:
Find the Quartile(Q3) of the list:
| Marks | 10 | 15 | 20 | 25 | 30 | 35 |
| No of students | 3 | 7 | 15 | 12 | 7 | 3 |
Type: Long Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Here,</p> <table width="252"><tbody><tr><td>Marks(x)</td> <td>No of students(f)</td> <td>c.f</td> </tr><tr><td>10</td> <td>3</td> <td>3</td> </tr><tr><td>15</td> <td>7</td> <td>10</td> </tr><tr><td>20</td> <td>15</td> <td>25</td> </tr><tr><td>25</td> <td>12</td> <td>37</td> </tr><tr><td>30</td> <td>7</td> <td>44</td> </tr><tr><td>35</td> <td>3</td> <td>47</td> </tr><tr><td>Total</td> <td>N= 47</td> <td></td> </tr></tbody></table><p>N= 47</p> <p>Q<sub>3</sub>lies in 3(\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p>= 3(\(\frac{47+1}{4}\))<sup>th</sup> item.</p> <p>= 3\(\times\) 12</p> <p>= 36<sup>th</sup> item.</p> <p>In given data, 36<sup>th</sup> item lies in 25 marks.</p> <p>Therefore, Q<sub>3</sub> = 25</p>
Q19:
Find the quartile(Q1) of the list:
| Marks | 24 | 36 | 50 | 65 | 78 |
| No of students | 2 | 4 | 12 | 11 | 6 |
Type: Long Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <table width="202"><tbody><tr><td>Marks(x)</td> <td>No of students(f)</td> <td>c.f</td> </tr><tr><td>24</td> <td>2</td> <td>2</td> </tr><tr><td>36</td> <td>4</td> <td>6</td> </tr><tr><td>50</td> <td>12</td> <td>18</td> </tr><tr><td>65</td> <td>11</td> <td>29</td> </tr><tr><td>78</td> <td>6</td> <td>35</td> </tr><tr><td>Total</td> <td>N= 35</td> <td></td> </tr></tbody></table><p>N= 35</p> <p>Here, Q<sub>1</sub>lies in (\(\frac{N+1}{4}\))<sup>th</sup> item.</p> <p>= (\(\frac{35+1}{4}\))<sup>th</sup> item.</p> <p>= \(\frac{36}{4}\)<sup>th</sup> item.</p> <p>=9<sup>th</sup> item.</p> <p>In the given data, 9<sup>th</sup> item lies in 18 c.f.</p> <p>Therefore, Q<sub>1</sub> = 50</p>
Q20:
Find the first and third quartile of the list:
| x | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 | 60-70 | 70-80 |
| f | 8 | 9 | 7 | 15 | 22 | 12 | 7 |
Type: Long Difficulty: Easy
Show/Hide Answer
Answer: <p>Solution:</p> <p>Here,</p> <p>20-30</p> <table width="234"><tbody><tr><td>x</td> <td>f</td> <td>c.f</td> </tr><tr><td>10-20</td> <td>8</td> <td>8</td> </tr><tr><td>20-30</td> <td>9</td> <td>17</td> </tr><tr><td>30-40</td> <td>7</td> <td>24</td> </tr><tr><td>40-50</td> <td>15</td> <td>39</td> </tr><tr><td>50-60</td> <td>22</td> <td>61</td> </tr><tr><td>60-70</td> <td>12</td> <td>73</td> </tr><tr><td>70-80</td> <td>7</td> <td>80</td> </tr><tr><td></td> <td>N=80</td> <td></td> </tr></tbody></table><p>Now,</p> <p>Q1 Class = value of (\(\frac{N}{4}\))<sup>th</sup> item</p> <p>= value of ( \(\frac{80}{4}\))<sup>th</sup> item</p> <p>= value of 20<sup>th</sup> item</p> <p>In c.f. column, c.f. just greater than 20 is 24 and its corresponding class is (30-40).</p> <p>\(\therefore\) Q<sub>1</sub> lies in the class 30-40</p> <p>Here,</p> <p>\(\frac{N}{4}\) = 10, l= 30, c.f. =17, f = 7and i =10</p> <p>\(\therefore\)Q<sub>1</sub>= l + \(\frac{\frac{N}{4}− c.f}{f}\) × i</p> <p>= 30 + \(\frac{20−17}{7}\) ×10</p> <p>= 30 + \(\frac{3}{7}\) ×10</p> <p>= 30 +4.28</p> <p>= 34.28</p> <p>Again,</p> <p>Q<sub>3</sub> Class = value of(\(\frac{3N}{4}\))<sup>th</sup> item</p> <p>= value of(\(\frac{3 * 80}{4}\))<sup>th</sup> item</p> <p>=value of 60<sup>th</sup> item</p> <p>In c.f. column, c.f.just greater than 60 is 61 and its corresponding class is 50-60.</p> <p>Here,</p> <p>\(\frac{3N}{4}\) = 60, l= 50, c.f. = 39, f = 22 and i =10</p> <p>\(\therefore\)Q<sub>3</sub>= l + \(\frac{\frac{3N}{4}− c.f}{f}\) × i</p> <p>= 50 + \(\frac{60− 39}{22}\) ×10</p> <p>=50 + \(\frac{21}{22}\) ×10</p> <p>= 50 +9.54</p> <p>=59.54</p>
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Nemathelminthes
Nemathelminthes is composed of two words i.e. nematodes which mean thread and helminths which mean worm. Gegenbaur coined the term nemathelminths in 1859.
General characteristic features of Nemathelminthes:
- They are cylindrical, elongated, unsegmented and worm-like.
- They are mostly parasitic and some are free living found in soil and water.
- They are triploblastic.
- They are bilaterally symmetrical.
- Coelom is pseudo coelom type i.e body cavity s lined by mesodermal layer.
- Nutrition is a holozoic type.
- The alimentary canal is complete and straight. Mouth is terminal surrounded by lips.
- The respiratory system is absent. Respiration is anaerobic type in parasitic forms only.
- Transport of fluid nutrients takes place with the help of hydro lymph or pseudocoelomate fluid.
- The body is covered with the thick non-living cuticle.
- It consists of lateral excretory ducts which collect the excretory substances and expel out through the anus.
- It consists of nerve ring ana a longitudinal nerve cord. sense organs are poorly developed.
- They are unisexual or dioecious and sexual reproduction takes place.
- Fertilization is internal.
- Development may be direct or indirect with some larval stages.
- The body has not the distinct head.
Classification:
It is classified into two classes on the basis of presence and absence of amphids.
Phasmida:
- Caudal sense organ(phasmid) is present.
- Most of them are parasitic forms.
- Example: Ascaris, Trichuris.
Aphasmida:
- Caudal sense organ is absent.
- Most of them are free-living forms.
- Amphids or anterior sensory organs are present.
- Example: Dorylaimus, Rotifers.
Lesson
Introduction to kingdom Animalia
Subject
Biology
Grade
Grade 11
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