- 3:2:1:2 is the ratio of our dentition. Here 1 represents ----
- Large protein molecules are broken down in ---- of digestive tract
- ---- is the strong acid which is secreted during digestion
- Olfactory receptors present in ---- triggering signals to brain
- pH of saliva is ---- in nature
Answer:
- Canine
- Stomach
- HCl
- Nose
- Alkaline nature
Fill in the blanks with suitable words given below?
Fluctuations of hormone --(i)-- levels results in sensation of hunger and motivation of consuming food. When you feel your stomach is full and there is no need of food any more. Another hormone --(ii)-- that gets secreted suppresses hunger. When we take food into the mouth it has to be chewed thoroughly. For this purpose the --(iii)-- muscles help in chewing actions, while the --(iv)-- muscles of the jaw moves the jaw up,down, forward and backward during food mastication. The --(v)-- nerve controls the muscles of the jaw. Under the action of --(vi)-- nervous system Saliva is released by the salivary glands moistens the food to make chewing and swallowing easier. The salivary --(vii)-- in the saliva breaks down the starch into sugars. As a result of chewing the food is transported into the oesophagus by the action of swallowing which is coordinated by the swallowing centre in the --(viii)-- and the --(ix)--. The tongue which is gustatory recognizes the taste and --(x)-- nerve plays an important role in sensation of taste.
Choose the right ones.
i) leptin, ghrelin, gastrin, secretin.
ii) ghrelin, leptin, secretin, gastrin.
iii) deep muscles, surface muscles, circu lar muscles, striated muscles.
iv) surface muscles, deep muscles, neck muscles, long muscles.
v) fifth cranial nerve, second cranial nerve, fifth facial nerve, spinal nerve.
vi) central nervous system, peripheral nervous system, autonomous nervous system.
vii) lipase, sucrase, galactase, amylase.
viii) medulla oblongata, cerebrum, 8th spinal nerve, cranial nerve, 7th cranial nerve.
ix) Pons varoli, brain stem, medulla oblongata, mid brain.
x) 6th cranial nerve, 5th cranial nerve, 10th cranial nerve, optic nerve.
Answer:
- ghrelin
- leptin
- surface
- deep
- fifth cranial
- autonomous
- amylase
- medulla oblongata
- brain stem
- fifth cranial nerve
Choose the correct answer.
1. In which of the following situations you can taste quickly? [ ] ?
- Put sugar cristals on tongue
- Put sugar solution on tongue
- Press the tongue slowly against the palate
- Swallow directly without grinding and shredding
Answer: C
2.Peristalsis is because of [ ] ?
- Contraction of longitudinal muscles
- Contraction of circular muscles
- Under control of autonomous nervous system
- Digestive secretions
Answer: C
3.Sphincter that helps in opening of stomach into duodenum [ ] ?
- Cardiac
- Pyloric
- Anal
- Gastric
Answer: B
3.Glucose and amino acids are absorbed through the following part of villus [ ] ?
- epithelial cells
- blood capillary
- lymphatic vessel
- all
Answer: A
4.The region in brain portion that controls hunger signals [ ] ?
- medulla
- diencephalon
- cerebrum
- mid brain
Answer: B
5.Human organism is an internal combustion machine because of .. [ ] ?
(OR)
Human being is an "Internal combustion machine" because he/she
- assimilation of energy from food
- liberate CO2 during respiration
- expel waste food at the end state of digestion
- secrete powerful digestive juices
Answer: A
10th Class Biology 7th Lesson Coordination in Life Processes InText Questions and Answers
10th Class Biology Textbook Page No. 145
Question 1.
How do we know that we need food?
Answer:
When we feel hungry then we know that we need food
10th Class Biology Textbook Page No. 146
Question 2.
What plays a major role to identify stale food?
Answer:
Smell or odour plays a major role to identify stale food
Question 3.
If you are having a tasty dish do you think the smell of it increases your appetite?
(OR)
Do the smell of tasty dish increases our appetite?
Answer:
Yes, the smell of tasty dish increases our appetite
Question 4.
What are your observations after chewing cumin, sounf, potato and apple?
Answer:
If we chew cumin, sounf, potato and apple we observe in order to taste the food material the food should dissolve in saliva
10th Class Biology Textbook Page No. 148
Question 5.
Are there any other sensation that affect taste?
Answer:
Temperature (hotness), coldness are the sensations that affect taste
Question 6.
What happens to your taste sensation while sipping hot milk or tea?
Answer:
We find something more tasty while we sipping hot milk or tea
Question 7.
What do you think could be the range of temperature for us to relish food items?
Answer:
30°C to 35°C could be the range of temperature for us to relish food items
10th Class Biology Textbook Page No. 149
Question 8.
What do you think that would happen if the salivary glands did not function in our mouth?
Answer:
- If the salivary glands do not function in our mouth, saliva will not release and the food do not get moistened and chewing it is difficult
- The taste of the food cannot be identified
- Carbohydrates in the food cannot be broken down and changed to dextrose and maltose molecules
Question 9.
Suppose your taste buds were affected what would happen to your interest in haying food?
Answer:
If my taste buds were affected I cannot identify the taste of food and also loose interest in having food
10th Class Biology Textbook Page No. 151
Question 10.
Does the level of saliva secretion change due to presence of food in the mouth?
Answer:
Yes, the level of saliva increases due to the presence of food in the mouth
Question 11.
Can the process of chewing go on in the absence of saliva?
Answer:
Yes, the process of chewing go on in the absence of saliva. But it is very difficult to chew food and swallow it
Question 12.
Does the saliva have any other roles to play?
Answer:
The enzyme present in saliva that is salivary amylase converts large molecules of carbohydrates into small molecules of sugar like maltose and dextrose
Question 13.
What is the use of such an increase in surface area of food?
Answer:
It helps in more surface area for the enzyme to act
Question 14.
What about the nature of medium for salivary amylase to act on food component?
Answer:
The nature of medium for salivary amylase to act on food component is alkaline
Question 15.
If we swallow food material directly without mastication what will happen?
Answer:
If we swallow food material directly without mastication, the food will not get digest easily and completely
Question 16.
Do you think the pH of our mouth changes?
Answer:
Yes, the pH of our mouth changes from acidic to alkaline by the release of saliva from salivary glands
10th Class Biology Textbook Page No. 152
Question 17.
What are the different systems that contribute to the proper functioning of digestion in the mouth?
Answer:
Endocrine, muscular, nervous systems contribute to the proper functioning of digestion in the mouth
Question 18.
After the digestive process in the mouth where does the food move to?
Answer:
After the digestion in the mouth the food move to oesophagus
10th Class Biology Textbook Page No. 153
Question 19.
What are the systems that come into play for swallowing food?
Answer:
Skeletal system, nervous system and digestive systems come into play for swallowing food
Question 20.
What does the schematic diagram tell us about the oesophagus?
Answer:
The schematic diagram of the oesophagus tells about its structure, secretion and function
Question 21.
What kind of the tube is oesophagus?
Answer:
Oesophagus is a muscular and an elastic tube
Question 22.
How does mucus help in passage of food?
Answer:
Mucus helps in lubricating and protecting the oesophageal wall and helps the bolus to slide down easily in the oesophagus
10th Class Biology Textbook Page No. 154
Question 23.
What makes the movement of the food bolus in the oesophagus easy?
Answer:
- Mucus helps the food bolus to slide down easily
- Peristaltic movements of the walls of oesophagus also make the movement food bolus in the oesophagus easy
Question 24.
Why do you think the stomach is structured like a bag rather than a tube like an oesophagus?
(OR)
Why stomach is structured like a bag rather than like a tube?
Answer:
- The food taken has to remain in the stomach for a long time for proper digestion with digestive juices and enzymes
- Different kinds of muscles churns the food by contraction and relaxation to form chyme
- If it was like a tube the food would just pass down without under going much changes and cannot remain in the stomach for long time
Question 25.
What sets such processes into action?
Answer:
- When the food is in the oral cavity, the nerves in the cheek and tongue are stimulated
- These carry messages in the form of nerve impulses to the brain
- They messages are transmitted from the brain, to the wall of the stomach, and stimulate the gastric glands to produce gastric juice
10th Class Biology Textbook Page No. 155
Question 26.
What stimulates stomach muscle into action?
Answer:
The nervous system stimulates stomach muscle into action
Question 27.
What causes the stomach to churn and mix the food?
Answer:
The contractions of the stomach muscles squeeze and mix the food with the acids and juices of the stomach
Question 28.
Why should only a small quantity of food be passed from stomach to duodenum?
Answer:
For the complete digestion of chyme, only a small quantity of it be passed from stomach to duodenum
Question 29.
What is involved in bringing about peristalsis?
Answer:
Contraction and relaxation of the muscles present in various parts of gut bring about peristalsis
Question 30.
What is the direction of peristalsis? Which end of the gut does it begin?
Answer:
The direction of peristalsis is forward direction that is from mouth to anus
Question 31.
What happens if the direction of peristalsis is reversed?
Answer:
If the direction of peristalsis is reversed the food present in the gut moves backwards
10th Class Biology Textbook Page No. 157
Question 32.
Why do you think small intestine is long and coiled?
Answer:
The small intestine is long and coiled because the food has to stay for more time for complete digestion and absorption
Question 33.
What process is involved in this process of absorption?
Answer:
Selective absorption of nutrients by the villi of small intestine is involved in absorption
Question 34.
What is the relation between finger-like structures and paper folds?
Answer:
- Finger-like structures increase the surface area
- The space inside the paper folds is very much high. So area is increased
- So increase in surface area is the relation between finger-like structures and paper folds
Question 35.
What systems do you think are working together?
Answer:
The digestive system and circulatory system are working together
Question 36.
Do you think those systems work together in the whole length of the digestive canal? Why / Why not?
Answer:
No, these systems are not working together in the whole length of the digestive canal. The digested food material is absorbed only in the small intestine but not elsewhere in the gut
10th Class Biology Textbook Page No. 158
Question 37.
Often you may have experienced that if you have tension for some reason you start having loose motions. What does this show us?
Answer:
If we are tensed for some reason, the enteric nervous system or second brain loses control over the gut. Hence without our intervention, loose motions occur
10th Class Biology Textbook Page No. 159
Question 38.
What moves out of the gut?
Answer:
The indigested food material moves out of the gut
Question 39.
Two major pathways of waste expulsion are shown above. Which of the two do you think happens exclusively through the gut?
Answer:
Indigested food matter is expelled in the form of stool from the gut
Question 40.
What controls the exit of stools from the body?
Answer:
The two muscular layers present In the anal sphincter control the exit of stools from the body
Question 41.
Do you think the control is voluntary? Why / Why not?
Answer:
Yes, the control is voluntary in adults and it is involuntary in infants
Question 42.
Did we have a sphincter in any other part of the digestive canal? Where was it?
Answer:
Yes. We have a sphincter at the opening where stomach opens into duodenum (small intestine)
10th Class Biology Textbook Page No. 160
Question 43.
What is the fate of the digested substances that move into blood from the intestine?
Answer:
The digested substances reach each cell of the body through circulatory system. There it gets oxidised and release energy
Question 44.
Where is the energy stored?
Answer:
The energy is stored in the cells as ATP
Question 45.
Which system do you think will remove the excess salts from our body?
Answer:
The excretory system remove the excess salts from our body
Question 46.
What would be the path of salt removed from gut to the outside of our body?
Answer:
- The digested food containing salts will be absorbed into the blood stream in small intestine
- The circulatory system supplies this to kidney through renal artery
- In the kidney salts are filtered and sent out of the body along with urine
- Some of the salts also supplied to the skin. They will be sent out of the body in the form of sweat
10th Class Biology 7th Lesson Coordination in Life Processes Activities
Activity - 1
Observe the following table, identify and tick those options that you think makes you feel hungry?
Table
Smell of food |
Taste of food |
Sight of food |
Being tired and exhausted |
Need of food |
Thought of food |
? |
? |
? |
? |
? |
? |
i) What stimulates hunger?
Answer:
Smell of food, sight of food and need of food stimulates hunger
ii) What would be the result of stimulation of hunger?
Answer:
Hunger pangs occur in the stomach
iii) Which system do you think would send the signals to make us realize that we are hungry?
Answer:
Nervous system
iv) What kinds of controls are exercised during sensation of hunger? Are they hormonal or nervous or both?
Answer:
They are both hormonal and nervous
v) Can you suggest any four systems involved in the process of generating hunger sensation?
Answer:
Digestive system, Endocrine system, Circulatory system and Nervous system
Activity - 2
Observation of how our taste is affected by the sense of smell. (OK) How our taste is affected by the sense of smell?
- First, close your nose with your fingers
- Pop in some zeera in your mouth and chew it for some time
- After that chew some sounf
- Could you recognise the taste
- How long it taken to know the taste
- After sometime wash your mouth and repeat the activity by chewing a piece of an apple followed by a potato (remember to close your nose)
Could you know the taste of both or did it taste the same? Why?
Answer:
No, because taste buds couldnt send the taste signals to brain
Observation :
- We can taste the food that is in the form of liquid only
- Only after the dissolved food enters into the cup like taste buds, the sense of taste is carried to the brain for analysis. Then only we will know the taste of food material
- Similarly olfactory receptors which trigger signals in the form of nerve impulses to the brain where smell is detected
i) What happens when we put a food material in our mouth?
Answer:
Our mouth salivates
ii) Name the parts in the mouth that help us to taste food?
Answer:
Papillae (taste buds), palate
Activity - 3
- Take a pinch of asafoetida powder/garlic and rub it on hand kerchief/tissue paper
- Close your eyes and smell it
- Then try to identify taste of different types of food materials with the help of your friend
i) Does garlic have a stronger scent than apple? How do you think the stronger scent affect your sensation of taste?
Answer:
Yes, garlic have a stronger scent than apple. The stronger scent motivate us to eat different types of foods
ii) How many food materials you have identified correctly?
Answer:
Seven.
iii) Write a few lines on the relation between smell and taste?
Answer:
- Taste and smell are intimately entwined. This close relationship is most apparent in how we perceive the flavour of food
- Taste itself is focussed on distinguishing chemicals that have sweet, salty, sour, bitter or umami taste
- However interactions between the senses of taste and smell enhance our perceptions of the foods, we eat
iv) Have you ever felt that a particular food is tasty just by looking at it?
Answer:
I felt so many times. In general, we prefer the food material, which is attractive to our eyes and flavour to nose, then we taste it
Activity - 4
What is the role of different parts of the mouth in helping us to taste keeping sugar crystals over the tongue?
- Place some sugar crystals on the tongue and keep mouth opened and see that your tongue dosent touch the palate
- Record the time from the moment you placed the crystals on your tongue till you got the taste by using stop watch
- Now repeat the test by placing the sugar crystals on the tongue and pressing it against the palate
- Record the time from placing sugar crystals to getting the taste. Or put a drop of sugar solution on your tongue using a dropper
Observation :
Based on the above activity we know that taste can be identified easily when the tongue is pressed against the palate.
i) Can we taste on dry tongue?
Answer:
No. We cant taste on dry tongue
ii) Which way helped you taste faster? Why?
Answer:
Taste can be identified faster when the tongue is pressed against the palate.
When the tongue is pressed against the palate the food substance is pressed against the opening of the taste bud letting it reach taste celjs triggering taste signals. Finally the taste is recognised in the brain
Activity - 5
How do you show that the breakdown of food by using the model of chalk piece kept in vinegar?
- Break a piece of chalk into two halves
- Crush one half to tiny pieces leaving the other as it isv
- Take two small mineral wafer bottles QA ltr bottle) cut them into two equal halves and discard the upper portion
- Now we have two beakers from the lower cut portion
- Fill them half with vinegar and add the crushed chalk to one beaker and the other uncrushed half chalk to the other
- Observe them after half-an-hour or so
i) Which one dissolved faster the crushed chalk or the whole one?
Answer:
Beaker with crushed chalk dissolved faster than the whole one.
This experiment tells us the need of mechanical crushing of food the mouth to increase surface area for action of substances that aid in digestion
ii) How does this process of mechanical crushing go on in the mouth?
Answer:
Mechanical crushing of food goes in the mouth by chewing
iii) Which parts in the mouth are involved in this?
Answer:
Teeth and tongue
iv) What are the systems involved in this process?
Answer:
Digestive system, Nervous system, Muscular system
Activity - 6
Observe the diagram and answer the questions and fill the table.
i) Observe the model or chart of jaw, on the basis of the figure try to guess what are the functions molars could be?
Answer:
Chewing and grinding
ii) What do you think could be the function of inscisors?
Answer:
The function of inscisors is biting the food
iii) Which set of teeth helps in grinding food?
Answer:
Premolars and molars
iv) Which set helps in tearing food?
Answer:
Canines help in tearing food
v) What is your dental formula?
Answer:img is the dental formula
Table
Name of teeth |
Number |
Shape |
Function |
Incisors |
8 |
Chisel, sharp edges |
Biting |
Canines |
4 |
Sharp, pointed edges |
Tearing |
Premolars |
8 |
Diamond shape blunt and flat |
Chewing and grinding |
Molars |
12 |
Rectangular, blunt and flat |
Chewing and grinding |
Activity - 7
Testing pH of mouth at intervals of one hour?
- Collect a strip of pH paper with a colour chart from a chemistry teacher
- Take a small piece of the pH paper and touch it to your tongue
- Match the colour with the colour chart and note the pH
- Take some readings after having your food at lunch break
- Compare your readings with that of your friend
- Take at least 4 readings
Table
S.No |
Name of the Student |
pH value before lunch |
pH value after lunch |
pH value after an hour |
pH value after an hour |
1 |
Sagar |
7.4 |
6.8 |
7.0 |
7.4 |
2 |
San jay |
7.4 |
6.8 |
7.0 |
7.4 |
3 |
Raju |
7.1 |
6.9 |
7.0 |
7.1 |
4 |
San jay |
7.3 |
6.8 |
7.0 |
7.3 |
5 |
Kiran |
7.4 |
6.8 |
7.0 |
7.4 |
6 |
Yadav |
7.2 |
6.7 |
7.0 |
7.2 |
i) What is the usual range of pH of your mouth Acidic (or) Basic?
Answer:
The usual range of pH of our mouth is more or less 6.5. At low level the saliva is acidic and at high level it is basic
ii) Did you observe any change in pH after eating? What may have caused the change?
Answer:
Yes, 1 observed the change in pH. Bicarbonates in saliva changed that into basic
iii) In what kind of pH do you think salivary amylase acts well?
Answer:
In the pH range 7.2 to 7.4 it acts well in alkaline medium
iv) Does this type of food have any role to play on the pH of our mouth?
Answer:
If the food that enters is acidic it will be converted into basic stuff and then it is swallowed.
Based on the above tests we know that salival secreted causes the medium to change to alkaline as it aids in action salivary amylase
Activity - 8
Making a model of oesophagus to observe how bolus moves forward?
- Take a piece of waste cycle tube and insert one or two potatoes into it
- Lubricate the inner side of the tube with oil
- In the same way smear oil over potatoes
- Insert oil coated potatoes in the tube
- Now try to push the potatoes by squeezing the tube
i) How do you squeeze the tube to make the potatoes pass through?
Answer:
By pushing the potato from behind
ii) Do you think that the muscles in the wall of the oesophagus have to do something like this?
Answer:
Yes
iii) How did oil help you in pushing the potatoes through the pipe?
Answer:
Oil acted as a lubricant to push the potato easily in the forward direction
Activity - 9
How is the stomach protected from the secretions of its own acids?
- Take two similar green leaves
- Grease one leaf with petroleum jelly, leave the other free
- Add 1 or 2 drops of some weak acids on both the leaves
- Observe them after half-an-hour or so and write your observations
i) Which leaf was effected by the acid?
Answer:
The leaf to which petroleum jelly was not applied
ii) What kind of change did you observe in the leaves?
Answer:
The colour of the leaf changes
iii) What saved the other leaf from the effect of acid?
Answer:
Petroleum jelly.
From the above activity we can conclude that mucus secreted by the walls of stomach protects stomach from the harmful effects of hydrochloric acid
Activity - 10
Paper tube and folded papers.
- Provide students with a piece of paper
- Let them calculate the area of one side of the paper and make a roll of it
- Try to fill the tube by inserting few folded papers as much as possible in it
- Pull out the papers from the tube, unfold them and find out the whole area of the papers