Perianth of Flower

The perianth is a non-reproductive part of a flower. It contains both calyx and corolla. This note contains detail information about calyx and corolla.

Summary

The perianth is a non-reproductive part of a flower. It contains both calyx and corolla. This note contains detail information about calyx and corolla.

Things to Remember

  • The perianth is a non-reproductive part of a flower. It contains both calyx and corolla.
  • Calyx is the outermost whorl individual unit of sepal.
  •  Free sepal makes polysepalous condition and fused sepals make gamosepalous condition. 
  • Corolla is a second colored whorl of flower individual unit of which is petal. 
  •  The posterior largest petals are known as standard or vexillum.
  • Two lateral medium sized petals are known as wings or alae.  
  • Two anterior smallest fused petals is known as keels(Carina)

 

MCQs

No MCQs found.

Subjective Questions

Q1:

What is a sound? Give any three sources of sound.


Type: Short Difficulty: Easy

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Answer: <p>A sound is a form of energy which gives us the sensation of hearing. Any three sources of sound are as follows,</p> <ul><li>Animals</li> <li>Vehicles</li> <li>Musical instrument</li> </ul>

Q2:

What is the transverse wave? Give any two examples of  the transverse wave.

 


Type: Short Difficulty: Easy

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Answer: <p>The wave in which the particles of the medium vibrates up and down perpendicular to the direction of the wave is called a transverse wave. Any two examples of the transverse wave are as follows,</p> <ul><li>Ripples produced on the water surface in a pond.</li> <li>Vibration of the stretched wave in musical instrument.</li> </ul>

Q3:

What is longitudinal wave? Give any two examples of longitudinal wave.


Type: Short Difficulty: Easy

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Answer: <p>The wave in which the particles of the medium vibrate to- and -fro (back and forth) in the direction of the wave is called longitudinal waves. Any two examples of longitudinal wave are as follows,</p> <ul><li>Soundwave</li> <li>Wave formed on a slinky when pulled and pushed.</li> </ul>

Q4:

What is the speed of sound in air, water and steel?


Type: Short Difficulty: Easy

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Answer: <p>The speed of sound in air is 332m/s.<br />The speed of sound in the water medium is 1498m/s.<br />The speed of sound in steel medium is 5200m/s.<br /><br /></p>

Q5:

The sound is a longitudinal wave, why?


Type: Short Difficulty: Easy

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Answer: <p>The wave in which the particles of the medium vibrate to- and- fro (back and forth) in the direction of the wave is called a longitudinal wave. Since, when a sound wave passes through the air, the particle of the air vibrate back and forth parallel to the direction of propagation of the sound wave. It forms a region of compression and rarefaction. So, the sound wave is a longitudinal wave.</p>

Q6:

What are the factors that affect the speed of sound in air?


Type: Short Difficulty: Easy

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Answer: <p>The factors that affect the speed of sound in air are as follows,</p> <ul><li>Density</li> <li>Temperature</li> <li>Humidity</li> <li>Wind</li> </ul><p></p>

Q7:

How does humidity affect the speed of sound in air?


Type: Short Difficulty: Easy

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Answer: <p>Humidity is the amount of water vapour present in the air. The presence of water vapour decreases the density of air. The speed of sound decreases when the density of sound increases. So, the speed of sound increases when the humidity of air increases and vice versa.</p>

Q8:

What are the differences between the  transverse wave and longitudinal wave?


Type: Short Difficulty: Easy

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Answer: <p>The differences between the transverse wave and longitudinal wave are s follows,</p>
<table width="468">
<tbody>
<tr>
<td><strong>Transverse wave</strong></td>
<td><strong>Longitudinal wave</strong></td>
</tr>
<tr>
<td>The particles of the medium vibrate perpendicular to the direction of propagation of sound.</td>
<td>The particles of the medium vibrates parallel to the direction of propagation of sound.</td>
</tr>
<tr>
<td>The wave travels in the form of crests and troughs.</td>
<td>The wave travels in the form of compression and rarefaction.</td>
</tr>
<tr>
<td>This wave can be polarised.</td>
<td>This wave cannot be polarised.</td>
</tr>
</tbody>
</table>

Q9:

Define crest and troughs.


Type: Short Difficulty: Easy

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Answer: <p>Crest is defined as the point of maximum displacement of a transverse wave and troughs is defined as the point of maximum negative displacement of a transverse wave. Crest is also known as peak.</p>

Q10:

Define compression and rarefaction.


Type: Short Difficulty: Easy

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Answer: <p>A compression is that part of a longitudinal wave in which the particles of the medium are closer to one another and rarefaction is the part of the waves in which the particles are farther apart.</p>

Q11: What is sound?
Type: Very_short Difficulty: Easy

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Answer: Sound is a form of energy which produces a sensation of hearing in the ears.

Q12: What is source of sound?
Type: Very_short Difficulty: Easy

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Answer: An object which produces sound is called a source of sound.

Q13:

Write any two sources of sound.


Type: Very_short Difficulty: Easy

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Answer: <p>Any two sources of sound are radio and guitar.</p>

Q14: What is wave?
Type: Very_short Difficulty: Easy

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Answer: Wave motion is a periodic disturbance travelling through a medium which is produced by a vibrating body.

Q15:

What is transverse wave?


Type: Very_short Difficulty: Easy

Show/Hide Answer
Answer: <p>The wave in which the particles of the medium vibrate up and down perpendicular to the direction of the wave is called a transverse wave.</p>

Q16: What is longitudinal wave?
Type: Very_short Difficulty: Easy

Show/Hide Answer
Answer: The wave in which the particles of the medium vibrate to -and -fro (back and forth) in the direction of the wave is called a longitudinal waves.

Q17: What happens to the speed of sound when the density of air increases?
Type: Very_short Difficulty: Easy

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Answer: The speed of sound decreases when the density of air increases.

Q18: What happens to the speed of sound when the temperature of the air increases?
Type: Very_short Difficulty: Easy

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Answer: The speed of sound also increases when the temperature of air increases.

Q19: What is the speed of sound in air?
Type: Very_short Difficulty: Easy

Show/Hide Answer
Answer: The speed of sound in air is about 332m/s.

Q20: What is the speed of sound in steel medium?
Type: Very_short Difficulty: Easy

Show/Hide Answer
Answer: The speed of sound in steel medium is 5200m/s.

Q21:

In which medium does the sounds travel faster?


Type: Very_short Difficulty: Easy

Show/Hide Answer
Answer: <p>Sound travel faster in a solid medium.</p>

Q22:

What kind of wave is sound wave?


Type: Very_short Difficulty: Easy

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Answer: <p>Soundwave is a mechanical wave because sound needs material for its transmission.</p>

Q23: How do you produce sound?
Type: Very_short Difficulty: Easy

Show/Hide Answer
Answer: Sound can be produced due to vibration of molecules of an object.

Q24: Why does sound move faster in air or water?
Type: Very_short Difficulty: Easy

Show/Hide Answer
Answer: The molecules of solids are very much close to each other and their numbers in solids are more than liquid and gases. So, sound move faster in solid than liquid or gases.

Q25: What is the speed of sound in water?
Type: Very_short Difficulty: Easy

Show/Hide Answer
Answer: The speed of sound in water is about 1498m/s.

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Perianth of Flower

Perianth of Flower

The perianth is a non-reproductive part of a flower. It contains both calyx and corolla.

Calyx

Calyx is the outermost whorl individual unit of the sepal. Free sepal makes polysepalous condition and fused sepals make the gamosepalous condition. Sometimes sepals instead of becoming green color attain the color of petal and are then known as petaloid sepals.

Duration:

Caducous: Sepals falling off much earlier i.e. before the opening of a flower.

Deciduous: Sepals remaining till the maturity of a flower.as

Persistent: Sepals remaining till the maturity of the fruit.

Corolla:

Corolla is a second colored whorl of flower individual unit of which is petals. Free petals make polypetalous condition and fused petals make a gamopetalous condition. Green petals are termed as sepaloid petals. source:www.biologydiscussion.com

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source:www.biologydiscussion.com

Cruciform corolla:

The presence of four free petals arranged in a cross-like manner and each petal differentiated into the broad limb and pointed claw. Eg; Brassicaceae

Caryophyllaceous corolla:

The presence of five free petals each petal differentiated into an elongated claw and broad limb placed at a right angled to each other. Eg; family Caryophyllaceae

Papilionaceous corolla:

The presence of five unequal sized petals. The posterior largest petals are known as standard or vexillum. Two lateral medium sized petals are known as wings or alae. Two anterior smallest fused petals is known as keels(Carina). These petals give a butterfly-like appearance to the flower. Eg; Pea

Tubular:

Petals fused to form a tube-like structure.

Campanulate:

Petals fused to form bell-shaped structure.

Infundibuliform:

Petals fused to form funnel-shaped structure.

Lesson

Angiosperm

Subject

Biology

Grade

Grade 11

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