Getting To Know Plants - Class 6 Biology - Extra Questions

What is leaf venation ? Explain different types of leaf venation Give one example each

The arrangement formed by veins on the leaves is called leaf venation. There are two types of venation are as follows:
(i) Reticulate venation - In reticulate venation, veins are arranged in the form of a network, e.g., Mango, peepal, etc.
(ii) Parallel venation - In parallel venation, veins are arranges in parallel to each other, e.g., grasses, banana, etc.


(a) Write short notes on Sushrut.
(b) Give the names of active ingredients and their one uses of following medicinal plants.
     (i) Amla, (ii) Haldi, (iii) Tulsi.

(a) Sushrut: Sushrut was a renowned surgeon of ancient India and author of the book Sushrut Samhita. He was the first physician to advocate what is today known as 'Caesarean operation'. He was also expert in locating and treating fractures, removing urinary stones and in doing eye operation for cataract.
(b) 
(i) Amla
    Active ingredients : Vitamin $$C$$
    Uses                     : In fever, Diabetes, Asthama etc.
(ii) Haldi
     Active ingredients : Curcumin
     Uses                    : As an antiseptic and antibiotic. Headache, swelling of eyes etc.
(iii) Tulsi
      Active ingredients : Cineole and Eugenol
      Uses                     : In skin diseases ear pain, cough and cold etc.


List few plants found around your house.

The names of few plants found around the house are mango, papaya, neem, jamun, chilli, coconut and banyan tree.


Describe following medicinal plants - (i) Haldi, (ii) Garlic, (iii) Amla, (iv) Jeera, (v) Maithi, (vi) Mahua.

(i) Haldi - It is an underground stem called rhizome having great medicine value. It is aromatic stimulant antiseptic in nature. So it is used for the treatment of various diseases.
(ii) Garlic - It is obtained from its underground part called bulb. It has great medicinal value. It is used for heart diseases, whooping cough, bronchitis. It has diuretic properties. It is also used to reduced fat from the body.
(iii) Amla - Raw fruits are used to cover the deficiency of vitamin-C. It is used for the treatment of stomach disorder, dysentery, diarrhoea and liver diseases. It is used to cure jaundice.
(iv) Jeera - Fruits of this plant are used for lactating mother. It is also used for digestion and for the treatment of diarrhoea.
(v) Maithi - Seeds and fruits are used as medicines. it is used to reduce fat from the body. It is used to cure nervous disorders.
(vi) Mahua - Leaves, seeds and fruits of the plants are used for the treatment of skin diseases. It is also used to cure seasonal cold and cough.


Are all the plants same in size?

No, not all plants are same in size. Plants are classified on the basis of their size into three categories are herbs (short plants with green and delicate stems), shrubs (medium-sized plants with bushy and hard stems with branches), and trees (big and tall plants with very thick and hard stems).


How many kinds of plants are there?

Plants are classifed on the basis of their size/ height into three types:
(i) Herbs- short plants with green and delicate stems
(ii) Shrubs- medium-sized plants with bushy and hard stems with branches
(iii) Trees- big and tall plants with very thick and hard stems


Write the names of active ingredients and the medicinal uses of the following medicinal plants:
(i) Amla, (ii) Haldi, (iii) Tulsi, (iv) Neem.

$$\textbf{Solution:}$$

$$\textbf{Part (i):}$$
Amla 
Active ingredients: Vitamin $$C$$
Uses: 
$$\bullet$$Improves the health of the liver.
$$\bullet$$Helps to maintain a healthy digestive system.
$$\bullet$$Promotes health heart
$$\bullet$$It will help you develop more hair.
$$\bullet$$Kidney health is improved.

$$\textbf{Part (iI):}$$
Haldi
Active ingredients: Curcumin
Uses: 
$$\bullet$$Helps with digestion.
$$\bullet$$Liver Anomalies Treatment
$$\bullet$$Helps You Lose Weight:
$$\bullet$$Immune system booster.
$$\bullet$$Wounds and ulcers are treated.
$$\bullet$$Improves cardiac function.
$$\bullet$$Pain And Inflammation Treatments

$$\textbf{Part (iii):}$$
Tulsi
Active ingredients: Cineole and Eugenol
Uses: 
$$\bullet$$Encourages a healthy heart. 
$$\bullet$$Treats Kidney Stones
$$\bullet$$Relieves Headaches.
$$\bullet$$Fights Acne
$$\bullet$$Relieves Fever

$$\textbf{Part (iv):}$$ 
Neem 
Active ingredients: Nimbidine or Azadectirine 
Uses:
Leprosy, eye disorders, bloody nose, intestinal worms, stomach distress, lack of appetite, skin ulcers, heart and blood vessel ailments (cardiovascular disease), fever, diabetes, gum disease (gingivitis), and liver problems are all treated with neem leaf. The leaf is also used to induce abortions and for birth control.


Name two plants that belong to herbs.

Herbs are short plants with green and delicate stems. The plants that belong to the category of herbs are: tomato, basil, wheat, grass, etc.


Give two examples of shrubs.

Shrubs are medium-sized plants with bushy and hard stems with branches. Examples of shrubs are rose, lemon, henna, orange, etc.


What is the relation between leaf venation and the type of roots?

  • Leaf venation and the type of roots in a plant are related in a very interesting way.
  • Venation is the arrangement of veins in the leaf lamina. 
  • Venation can be divided into two types:-
Parallel venation: When the veins are parallel and do not form a network, it is known as Parallel Venation. 
Plants with fibrous roots have parallel venation. For example:- Wheat, maize, grass, banana, bamboo, etc.
Reticulate venation: When the veins in leaves are irregularly distributed to form a channel, it is known as reticulate venation. 
Plants with reticulate venation in their leaves are likely to have tap roots. For example:- Carrots or roses.


What are stamens?

Stamen is the pollen- producing, male reproductive organ of a flower. 
When the sepals and petals are removed from the flower, some filaments can be seen. These filaments are the stamens. Stamens usually consist of a long slender stalk, the filament, with the anthers at the tip. 



What are herbs? Give two examples.

Herbs are short plants with green, delicate and tender stems. They may have no or less branches. The plants that belong to the category of herbs are: tomato, basil, wheat, grass, etc.


What are shrubs? Give two examples.

Shrubs are medium-sized plants with bushy and hard (but not thick) stems with branches. Their stem braches out near the base. Examples of shrubs are rose, lemon, henna, etc.


Classify plants according to their structure (habit) and give an example of each.

Plants are classified on the basis of various characteristics into three types:
(i)  Herbs- Short plants with green and delicate stems. Examples are basil, wheat, tomato, etc.
(ii) Shrubs- Medium-sized plants with bushy and hard stems with branches. Examples are rose, lemon, henna, etc.
(iii) Trees- Big and tall plants with very thick and hard stems. Examples are banyan, mango, cashew, neem, etc.


Give two examples of trees.

Trees are big and tall plants with very thick and hard stems. Examples of trees are banyan, mango, cashew, neem, papaya, etc.



Differentiate between tap root and fibrous root.

              Tap root            Fibrous root
Tap root has only one main and long root. The smaller roots that grow from the main root are called lateral roots
Fibrous roots do not have a main root. All roots are similar
Tap root grows vertically deep
into the soil		Fibrous roots are short and most of them grow horizontally in the soil
Tap roots are found in plants which have reticulate venation in their leavesFibrous roots are found in plants which have parallel venation in their leaves
Tap root is much longer and has extremely large surface area
Fibrous roots are short and have small surface area
Taproots are mostly found in dicotyledonsFibrous roots are found in monocotyledons


How is water absorbed by root hairs in plants? Explain.

In higher plants, water is absorbed through root hairs from the soil water. The walls of root hairs are permeable to water and are hydrophilic in nature. They contain vacuoles filled with cell sap. Absorption of water by roots takes place by two mechanism namely, active absorption and passive absorption. During active absorption, the root cells absorb water using metabolic energy released through respi­ration. Active absorption could be either osmotic absorption or non-osmotic absorption. In osmotic absorption, water is absorbed from the soil into the xylem of the roots in the osmotic gradient. In non-osmotic absorption, water is absorbed against the osmotic gradient. In passive absorption, water absorption is due to transpiration. In this, absorption of water into the root is due to conditions originate in the top of the plant and the root cells play a passive role. Osmotic concentration of the root cells is due to the presence of soluble metabolic products synthesized in the aerial parts of the plants and later translocated downwards to the root cells.


From where does the lateral root originate?

From pericycle of mature zone, lateral root originate.


Differentiate between tap root and adventitious root.

 Tap Roots Fibrous Roots
 1)Arises from radicle. 1)Arises from any part of a plant other than radicle.
 2)Primary root sustains throughout life. 2)Primary root is short lived.
 3)Always found underground. 3)It can be found underground or above the ground.
 4)The main root is thicker than lateral roots 4)All are generally fibrous.
 5)Its main function is absorption. 5)Its main function is to provide support.


Explain the purpose of modification of roots. 

The modification of root helps the plant to store the food to survive under unfavorable condition. The food is stored in form of starch and water. The modified root provides function other than absorption and support. 
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Consider a monocot and dicot plant available in your area. observe the plants and describe them in scientific language.

 Description Dicot Monocot
 RootTaproot system-
Diarch to hexarch(2 to 4 in number)		Fibrous root system-
Polyarch (more than 6 in number)
 StemVascular bundles are conjoint, collateral, and closed.Vascular bundles are conjoint collateral and open
 Secondary growth Present (characteristic of dicots)Absent
 phloem parenchyma Phloem parenchyma is presentPhloem parenchyma is absent 
 LeafDorsiventral
Two types of tissues are present palisade parenchyma and spongy parenchyma with large intercellular spaces		 Isobilateral
Only spongy parenchyma is present with a very small intercellular space


Define the structure of root

Typical root system is differentiated into 5 regions.
1. Root Cap (Calyptra): it is tip of root and protects root. It secretes mucilage that help plant to penetrate into soil.
2.Growing point or meristematic zone: It lies just behind the root cap with about 0.25-1.0 mm long, It adds cells to root cap and the basal region of the root.
3. Zone of elongation: Lies behind meristematic zone, increases the  length of the root. Absorption of water and minerals from the soil happens with the external cells in this area.
4. Root hair zone or zone of differentiation: it is the area where cell differentiate to form epiblema, cortex, endodermis, pericycle, xylem and phloem. Cells of epiblema elongate to form unicellular root hairs.
5. Zone of maturation: Forms the major portion of root system. 

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Distinguish between parasitic and epiphytic roots.

Epiphytic plants are those small plants that grow on the stem or branches of large trees. They depend on the large plants just as a holding surface. Epiphytic plants have two types of roots;
  • The clinging roots; that helps the epiphytic plant to get fixed on the barks of the tree.
  • The epiphytic roots; that hangs freely in the air and absorbs moisture and stores it with the help of specialized tissue called velamen.

Whereas, Parasitic plants are those that solely depends on a host plant for the nutrition. Roots of the parasitic plants, called as Haustoria or sucking roots, are small and specialized so that to penetrate into and absorb water and nutrients from the host tissue.


Identify and explain the process in the diagram.
841115_4a5d3d66573c491582d51e121bfaba36.jpg

$$\textbf{Explanation:}$$

The given diagram shows the process of photosynthesis.

$$\bullet$$ Photosynthesis is the process by which green plants prepare their own food in the form of glucose using carbon dioxide and water in the presence of sunlight.


  $$Carbon\ dioxide + Water \underset {chlorophyll}{\xrightarrow {light}}Glucose + Oxygen$$.


$$\bullet$$   The roots absorb water from the soil, carbon dioxide from the air enters through the stomata, and energy from sunlight is trapped by chlorophyll to prepare glucose.
$$\bullet$$   The process of photosynthesis  occurs inside the mesophyll cells present in the leaves.
$$\bullet$$   The sugar produced during this process is stored in the plant in the form of starch which can later be used to produce energy.

$$\textbf{Conclusion:}$$ Thus, green plants carry out the process of photosynthesis to produce their own food. 


How do the herbs and the shrubs survive under the shadow of large canopied trees in forest?

The herbs and bushes that develop on the ground dimension of the thick woods barely get any daylight because of the nearness of huge tree shades. They are very much adjusted to this circumstance. They make themselves ready to live with almost no daylight that gets through the edges of the canopies.



What are the five functions of a flower? (5 marks)

  • Flower is the reproductive organ of a flowering plant as it contains male and female reproductive structures.
  • The important functions of flowers are mentioned below:
1. Male and female gametes are produced inside respective reproductive structures within a flower that later fuse to form zygote.
2. Flowers provide nectar to attract certain pollinators like honeybees which later convert it into honey.
3. After fertilization, the ovary (Part of the female reproductive structure) is the one that develops into a fruit. In non-flowering plants, there are no fruits.
4. Petals are brightly coloured and scented to attract animals and insects for pollination that ultimately helps in fertilization.
5. Because of brightly colored petals, human beings cultivate and use flowers for various occasions, weddings, funerals, and expressing love, etc.


Write correct sequence of four steps of method for the preperation of temparary mount of stained leaf peel.

$$\textbf{Solution:}$$

Steps involved for the preparation of temporary mount of the stained leaf are given below:

$$\bullet$$ Remove a portion of the peel from the lower surface of a healthy leaf. This can be accomplished by folding the leaf over and gently pulling the peel apart with forceps. Keep the peel in a water-filled watch glass.

$$\bullet$$ In that watch glass, add a few drops of safranin stain. Take out the peel after 2-3 minutes and place it on a clean glass slide.

$$\bullet$$  Apply a drop of glycerin to the peel. Using a needle, gently place a clean coverslip over it. Using blotting paper, remove any excess stain and glycerin.

$$\bullet$$ Examine the slide with the compound microscope at various magnifications.



Write two names for the following type of plant: 
A tree 

Mango and neem are both tree type of plants. 
Trees are big and tall plants. They have very thick, woody and hard stems called the trunk. 


What is the difference? 

A tree and a shrub.

TreesShrubs
Plants that grow very tall and have strong, hard stems or trunks are called trees.Plants that grow up to a medium height are called shrubs. 
They have branches that are at some height above the ground. They have branches that are very close to the ground.
Mango tree, neem tree, etc. Oleander, hibiscus, etc. 


Write two names for the following: 

A shrub 

Lemon and henna


Observe figure and attempt the questions that follow it.
(a) Label the parts 1, 2, 3 and 4 in the diagram.
(b) What type of venation does the leaf has?
(c) What type of venation is seen in grass leaves?

1800185_d8e47faf65df46d69ac02bd192f49543.png

(a) 
Part 1 is called Petiole.
Part 2 is called mid rib.
Part 3 is called Lamina.
Part 4 is called Veins

(b) It is a reticulate venation. The veins spread out to give a net like appearance.

(c) Grass has parallel venation. 


Can the stem of a plant be compared with a street with two way traffic? Give reason. (5 marks)

  • The stem of a plant can be compared to two-way traffic because, in the stem, there are two types of tubes, one that carries water and minerals from roots to the leaves and other parts and the other that carry food from leaves to other parts of the plant and roots. 
  • This transportation of food and water is carried out by the vascular tissue of plants, i.e. xylem and phloem.
  • Xylem works to transport water along with nutrients from roots to stems and leaves.
  • Phloem is responsible for transporting sugars (food prepared by leaves through photosynthesis) from leaves to all other parts of plants.

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"I have a green tender stem and I am much shorter than you. Who am I?" 

I am a herb.
Herbs have green tender, unbranched stem with height less a meter.
Example, Rose


Short Notes:
In which plant will you look for mycorrhiza and coralloid roots? Also, explain what these terms mean.

Mycorrhiza is a symbiotic association between a fungus and the roots of a vascular plant. Mycorrhiza is found in some genus of gymnosperms; like Pinus.
Coralloid Roots: These roots show a symbiotic association but in this case, the association is with nitrogen-fixing cyanobacteria. Many nodules are formed in the roots giving them coralloid appearance. Examples are Cycas and plants of Leguminosae.


Write an answer to the following. 

Explain the characteristics of herbs with two examples. 

Herbs have the following characteristics: 
$$\bullet$$ They grow up to the size $$1-1.5$$ metres 
$$\bullet$$ They have green and flexible stems 
$$\bullet$$ They can live up to a few months or up to two years 
$$\bullet$$ Examples of herbs include tulsi, parsley, mint, etc. 


Choose the odd one out from the following:
Mango, Banyan, Palm, Chickpea 

Chickpea is the odd one out because it is a herb whereas, the rest of them are trees.


Find the odd one out.
Grape, Orange, Lemon, Hibiscus 

Grape is the odd one out because it is a climber while the rest of them are shrubs. 


How are roots useful to the plants? Give any two points.

Roots are useful to the plants in the following ways:
1. It absorbs water and minerals from the soil and transports it upward to various parts of a plant.
2. Roots are important to make the plant rigid in the soil. This helps in supporting the whole structure of the plant.


Roots obtain oxygen from air in the soil for respiration. In the absence or deficiency of $$O_2$$, root growth is restricted or completely stopped. How do the plants growing in marshlands or swamps obtain their $$O_2$$ required for respiration?

Plants which grow in marshlands or swamps have pneumatophores. These are vertical or negatively geotropic roots that arise from the underground roots. These are also called breathing roots as they bear openings called lenticels for gaseous exchange.
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Give an example of the following and draw generalized diagrams for the same:
Parallel Venation and Reticulate Venation

Reticulate venation
$$\bullet$$ When the veins of a leaf form a net-like arrangement, it is known as reticulate venation.
$$\bullet$$ Found in dicot plants like mango, guava, peepal, etc.



Parallel venation:
$$\bullet$$ When the veins run parallel and do not form a network, it is known as parallel venation.
$$\bullet$$ Found in monocot plants like banana, grass, maize, etc.




What is lamina?

The lamina is the green flat part of a leaf that is specialized for photosynthesis.



Define petiole.

Petiole is the stalk that supports a leaf in a plant and attaches the leaf blade to the stem. 



Why are root nodules useful for the plants?

Root nodules mostly occur in legume plants. These nodules contain nitrogen fixing bacteria named Rhizobium. The bacteria pick up nitrogen from soil atmosphere and convert it into organic compounds. This same pass into plant so that legumes become rich in proteins and other nitrogen compounds.


Explain the structure of a leaf with the help of a labelled diagram.

Answer-

Leaves are vital to the survival of plants. They help plants in a variety of ways, including producing food and oxygen through photosynthesis, balancing water loss, regulating gas exchange, and transporting the products of photosynthesis.
A leaf has two main parts:
(1) Petiole - the stalk that supports a leaf in a plant and attaches the leaf blade to the stem. 
(2) Lamina - the green flat part of a leaf that is specialized for photosynthesis. The lamina contains the following parts:
   (i) Midrib - the central, thick, linear vein with bundles of vascular tissue that runs along the length of a leaf is called midrib. 
  (ii) Veins - the lines on the green flat part in a leaf that provide support for the leaf and transport both water and food as they have vascular tissues xylem and phloem

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The plant parts such as root, stem and leaves are called vegetative parts. Why are they called so?

The plant parts like root, stem, and leaves are called vegetative parts because they have the power of growing asexually without getting involved in the process of reproduction. These do not contain any germ cells (sexually reproducing cells) but still are capable of giving rise to young plants by vegetative propagation. New shoot and root germinate from nodes and adventitious buds. Plants raised by vegetative propagation can bear
flowers and fruits earlier than those produced from seeds


Class 6 Biology Extra Questions