MICROBIAL CELL CULTURE, TEST (30/8/2020)

1. Differentiate between synthetic and complex medium used for microbial culture.

2. How does the metagenomics help in identification of novel genes present in the environment? Explain the process.

3. Suggest any three advantages of using Pichia pastoris as a eukaryotic expression.

4. What are the essential steps involved in the isolation of vitamin B12 from the microbe?

5. (a) Calculate the generation time of a bacterial population in which the number of bacteria increases from 104 / ml to 107/ml furing four hours of exponential growth. 

(b) Explain any two methods of measuring microbial growth.

(c) In which phase of growth is the specific growth rate of microbial cells calculated? On what factors does the specific growth rate depend?

SOIL Types of Soil, Lecture 3, Ch 9, Class 7

AMINOACIDS, STRUCTURE AND CLASSIFICATION

 

Amino acids are organic compounds that contain amine (–NH₂) and carboxyl (–COOH) functional groups, along with a side chain (R group) specific to each amino acid.^[1][2] The key elements of an amino acid are carbon (C), hydrogen (H), oxygen (O), and nitrogen (N), although other elements are found in the side chains of certain amino acids.

Structure of Amino acids

• All 20 of the common amino acids are alpha-amino acids. They contain a carboxyl group, an amino group, and a side chain (R group), all attached to the α-carbon.

Exceptions are:

• Glycine, which does not have a side chain. Its α-carbon contains two hydrogens.
• Proline, in which the nitrogen is part of a ring.
• Thus, each amino acid has an amine group at one end and an acid group at the other and a distinctive side chain. The backbone is the same for all amino acids while the side chain differs from one amino acid to the next.
• All of the 20 amino acids except glycine are of the L-configuration, as for all but one amino acid the α-carbon is an asymmetric carbon. Because glycine does not contain an asymmetric carbon atom, it is not optically active and, thus, it is neither D nor L.

Classification of amino acids on the basis of R-group

1. Nonpolar, Aliphatic amino acids: The R groups in this class of amino acids are nonpolar and hydrophobic. Glycine, Alanine, Valine, leucine, Isoleucine, Methionine, Proline.
2. Aromatic amino acids: Phenylalanine, tyrosine, and tryptophan, with their aromatic side chains, are relatively nonpolar (hydrophobic). All can participate in hydrophobic interactions.
3. Polar, Uncharged amino acids: The R groups of these amino acids are more soluble in water, or more hydrophilic, than those of the nonpolar amino acids, because they contain functional groups that form hydrogen bonds with water. This class of amino acids includes serine, threonine, cysteine, asparagine, and glutamine.
4. Acidic amino acids: Amino acids in which R-group is acidic or negatively charged. Glutamic acid and Aspartic acid
5. Basic amino acids: Amino acids in which R-group is basic or positively charged. Lysine, Arginine, Histidine

Nonpolar, Aliphatic amino acids:

Negatively charged amino acids

SOIL (Soil Profile) Lecture 2, Ch 9, Class7

SOLUTIONS OF WORKSHEET 1, WINDS, STORMS AND CYCLONES, CLASS 7 (CH-8)

 

Answer 1

1. Air
2. Less
3. Anemometer
4. Puri
5. Eye
6. On the ceiling

Answer 2

1. Lighter
2. Cyclone
3. Wind wane
4. 300
5. heating

 

Answer 3:

1. Lightning
2. Anemometer
3. Wind
4. Cyclone
5. Typhoon
6. Tornado
7. Thunderstorms
8. Hurricane

 

Answer 4:

The answer is c)

Explanation:

During summer land becomes heated, air over land rises. This makes the cooler air blow from the sea towards the land. This air is called as the sea breeze.

Answer 5:

The answer is (a) Blowing of air decreases pressure over the opening of the straw.

Explanation:

Decreased pressure over the opening of the straw makes the level of soft drinks rise.

Answer 6 :

The answer is (d) (iv)

Answer 7 :

Indian Ocean

Answer 8 :

THUNDER

CYCLONE

STORM

TYPHOON

LIGHTNING

Answer 9 :

Column-I	Column-II
a) On heating air	ii) Expands
b) On cooling air	iv) Rises

SOIL, Lecture 1, Chapter 9, Class 7

WORKSHEET 1, WINDS, STORMS AND CYCLONES, CLASS 7 (CH-8)

 Question 1.

Multiple choice questions:
(a) Which among the following exert atmospheric pressure?
(i) Land
(ii) Water
(iii) Air
(iv) All of these

(b) Compared to plains, the atmospheric pressure on hills is
(i) More
(ii) Less
(iii) Same
(iv) Constant

(c) The wind speed is measured by
(i) Wind vane
(ii) Barometer
(iii) Anemometer
(iv) Hygrometer

(d) Which of the following place is most likely to be affected by a cyclone?
(i) Mumbai
(ii) Puri
(iii) Goa
(iv) Porbandar

(e) The central calm area of a cyclone is called
(i) Core
(ii) Eye
(iii) Midpoint
(iv) None of these

(f) A fire alarm usually detects smoke in case of fire. Where should such an alarm be placed in a room?
(i) Near the door
(ii) On the floor
(iii) On the ceiling
(iv) On the wall

Question 2

Fill in the blanks
(a) warm air is_________________________than cold air.
(b) ___________________blow at a speed of 89-102 km hour.
(c)____________________used to measure direction of wind.
(d) A violent tornado can travel at speeds of about__________________km/hr.
(e) The main cause of wind movement is uneven ___________ on the earth.

Question 3

One word answer

1. It is a violent and sudden electrostatic discharge usually during a thunderstorm

2. The instrument to measure the wind speed
3. The moving air is called

4. The formation of a very low-pressure system with very high-speed winds revolving around it.
5. Japanese name for Cyclone
6. It is a dark funnel shaped cloud that reaches from the sky to the ground

7. The swift movement of the falling water droplets along with the rising air create lightning and sound.
8. American name for Cyclone

Question 4

Four schematic diagrams are shown in Figure 8.1 to depict the direction of the sea breeze. Which of them gives the correct direction?

Question 5

Figure shows a child blowing air with a straw near the opening of another straw which has its other end in a soft drink bottle. It was observed that the level of the soft drink in the straw rises up as soon as air is blown over its open end. Which one of the following best explains the reason for the rise in the level of the drink?

Question 6

 Following are precautions one must take in case a storm is accompanied by lightning.

(i) Do not take shelter under a tree.

(ii) Do not take shelter under an umbrella with a metallic end.

(iii) Do not take shelter in open garages, storage sheds, etc.

(iv) Do not take shelter in a bus in the open.

Which one of these is not correct?

Question 7

Name the ocean which is mainly responsible to bring rain-bearing monsoon winds to Kerala coast in June every year?

Question 8

Identify the names of six natural phenomena from the following word diagram given as Figure 8.5.

Question 9

Match Column I with Column II. There can be more than one match.

Column-I	Column-II
a) On heating air	i) Descends
b) On cooling air	ii) Expands
	iii) Contracts
	iv) Rises

SOLUTIONS OF BACK EXERCISE, CH 8 (WINDS, STORMS AND CYCLONES) CLASS 7

 Exercise Questions

1. Fill the missing word in the blank spaces in the following statements:

(a) Wind is——————air.

(b) Winds are generated due to——————heating on the earth.

(c) Near the earth’s surface __________air rises up whereas ___________ air comes down.

(d) Air moves from a region of ——— pressure to a region of——— pressure.

Solution:

(a) Wind is moving air.

(b) Winds are generated due to uneven heating on the earth.

(c) Near the earth’s surface, warm air rises up whereas cold air comes down.

(d) Air moves from a region of high air pressure to a region of low air pressure.

2. Suggest two methods to find out wind direction at a given place.

Solution:

Methods to finding out the wind direction at a given place are as follows

i. By seeing the direction of dry leaves released in the air.

ii By seeing the direction in which it is difficult to ride the bicycle.

3. State two experiences that made you think that air exerts pressure (other than those given in the text).

Solution:

i. When we fill the air in the balloon, it becomes tight and if we try to fill more air balloon will get burst which proves air exerts pressure.

ii. Wind causes curtains, doors and windows to move with the direction of the wind. This demonstrates air exerts pressure.

4. You want to buy a house. Would you like to buy a house having windows but no ventilators? Explain your answer.

Solution:

It is not a good idea to buy a house without ventilators because warm air is lighter than cold air hence warm air passes out of your home through ventilators. Accordingly, without ventilators, warm air will not pass out, and the house will remain warm.

5. Explain why holes are made in hanging banners and hoardings.

Solution:

Holes in the banners and hoardings helps air to pass through it. Hence banner can withstand the pressure of the air and hence remains intact.

6. How will you help your neighbours in case cyclone approaches your village/town?

Solution:

We can help our neighbours in case a cyclone approaches, by any of the following measures:

• By helping them shift to a safer place.
• By helping them to shift their animals, necessary households and vehicles to a safer place.
• By calling emergency services such as fire station, police and medical centres.

7. What planning is required in advance to deal with the situation created by a cyclone?

Solution:

• We should not ignore the warnings issued by the meteorological department through TV, radio, or newspapers.
• We should — make necessary arrangements to shift the essential household goods, domestic animals and vehicles, etc. to safer places;
• Avoid driving on roads through standing water, as floods may have damaged the roads.
• Phone numbers of all emergency services like police, fire brigade, and medical centres should be handy.
• Always store drinking water for emergencies.
• Do not touch wet switches and fallen power lines.
• Do not pressurise the rescue force by making undue demands.
• Cooperate and help your neighbours and friends.

8. Which one of the following place is unlikely to be affected by a cyclone.

(i) Chennai

(ii) Mangaluru (Mangalore)

(iii) Amritsar

(iv) Puri

Solution:

The answer is (iii) Amritsar because Amritsar is far away from the sea while the remaining three are coastal areas and are likely to be hit by cyclone.

9. Which of the statements given below is correct?

(i) In winter the winds flow from the land to the ocean.

(ii) In summer the winds flow from the land towards the ocean.

(iii) A cyclone is formed by a very high-pressure system with very high-speed winds revolving around it.

(iv) The coastline of India is not vulnerable to cyclones.

Solution:

The answer is (i) In winter, the winds flow from the land to the ocean.

SOLUTIONS OF WEATHER, CLIMATE AND ADPATATIONS, CLASS 7

1. Name the elements that determine the weather of a place.

Solution:

Temperature, humidity, rainfall and wind are the elements that determine the weather of a place.

2. When are the maximum and minimum temperatures likely to occur during the day?

Solution:

Maximum temperature occurs during day time, afternoon to be precise whereas minimum temperature occurs early in the morning.

3. Fill in the blanks:

(i) The average weather taken over a long time is called ___________.

(ii) A place receives very little rainfall and the temperature is high throughout the year, the climate of that place will be ___________ and ___________ .

(iii) The two regions of the earth with extreme climatic conditions are ___________ and __________.

Solution:

(i) The average weather taken over a long time is called climate.

(ii) A place receives very little rainfall, and the temperature is high throughout the year, the climate of that place will be hot and dry.

(iii) The two regions of the earth with extreme climatic conditions are polar region and tropical region.

4. Indicate the type of climate of the following areas:

(a) Jammu and Kashmir: _________________________________

(b) Kerala: ____________________________________________

(c) Rajasthan: __________________________________________

(d) North-east India: _____________________________________

Solution:

(a) Jammu and Kashmir: moderately hot and wet

(b) Kerala: hot and wet

(c) Rajasthan: hot and dry

(d) North-east India: wet

5. Which of the two changes frequently, weather or climate?

Solution:

Weather changes frequently but not climate

6. Following are some of the characteristics of animals:

(i) Diets heavy on fruits (ii) White fur

(iii) Need to migrate (iv) Loud voice

(v) Sticky pads on feet (vi) Layer of fat under skin

(vii) Wide and large paws (viii) Bright colours

(ix) Strong tails (x) Long and large beak

For each characteristic indicate whether it is adaptation for tropical rainforests or polar regions. Do you think that some of these characteristics can be adapted for both regions?

Solution:

(i) Diets heavy on fruits- Tropical rain forests

(ii) White fur – Polar regions

(iii) Need to migrate- Polar regions

(iv) Loud voice-Tropical rain forests

(v) Sticky pads on feet – Tropical rain forests

(vi) The layer of fat under skin – Polar regions

(vii) Wide and large paws – Polar regions

(viii) Bright colours – Tropical rain forests

(ix) Strong tails – Tropical rain forests

(x) Long and large beak – Tropical rain forests

I think that animals are differently adapted to survive in different climatic conditions.

7. The tropical rainforest has a large population of animals. Explain why it is so.

Solution:

Hot and humid temperature and continuous rainfall in the tropical rainforest suit the survival of many animals; hence, the tropical rainforest has a large population of animals.

8. Explain, with examples, why we find animals of certain kind living in particular climatic conditions.

Solution:

Animals are adapted to survive in the conditions in which they live. Animals living in very cold and hot climate must possess special features to protect themselves against the extreme cold or heat.

Example: Polar bears have white fur so that they are not easily visible in the snowy white background. It protects them from their predators. It also helps them in catching their prey. To protect them from extreme cold, they have two thick layers of fur. They also have a layer of fat under their skin. In fact, they are so well-insulated that they have to move slowly and often rest to avoid getting overheated.

Similarly, In rainforests, Red-eyed frog has developed sticky pads on its feet to help it climb trees on which it lives.

9. How do elephants living in the tropical rainforest adapt itself?

Solution:

Following are the adaptation of elephants in rainforests

• It uses the trunk as nose to have strong sense of smell
• The trunk is also used to pick food
• It has modified teeth tear the bark of trees which are food for elephants
• Large ears of the elephant help it to hear even very soft sounds.
• Ears help the elephant to keep cool in the hot and humid climate of the rainforest.

Choose the correct option which answers the following question:

10. A carnivore with stripes on its body moves very fast while catching its prey. It is likely to be found in

(i) polar regions (ii) deserts

(iii) oceans (iv) tropical rainforests

Solution:

The answer is (iv) tropical rainforests

11. Which features adapt polar bears to live in extremely cold climate?

(i) A white fur, fat below skin, keen sense of smell.

(ii) Thin skin, large eyes, a white fur.

(iii) A long tail, strong claws, white large paws.

(iv) White body, paws for swimming, gills for respiration.

Solution:

The Answer is (i) A white fur, fat below skin, keen sense of smell.

12. Which option best describes a tropical region?

(i) hot and humid

(ii) moderate temperature, heavy rainfall

(iii) cold and humid

(iv) hot and dry

Solution:

The answer is (i) hot and humid.

Thunderstorm and cyclones, Lect3, class7

Winds, Storm and Cyclones with activity, Lect2, Class 7

NOTES ON CYCLONES, CH 8, CLASS 7

 

Clouds are formed due to water vapour in the air.
As the water turns into vapour, it takes up the heat from the atmosphere.
When the water vapour turns into clouds and falls back as raindrops the same heat is released back into the atmosphere.
This heat warms up the air around the raindrops and the warm air starts rising.
This leads to decreasing their pressure in the region.
So, the air from the surroundings takes the place of the warm air. This cycle continues until the rain falls.
As a result, a very low-pressure region is created and strong winds start revolving in that low-pressure region. This is the condition of a cyclone.
The formation of a cyclone that depends upon different factors:
the temperature of the place
the wind speed
the direction of the winds
the humidity of the place
Figure 7 Formation and Structure of A Cyclone
Structure of a Cyclone
Cyclone is a rotation of air in the atmosphere at a height of around 10 to 15 km.
The centre of the cyclone(also called the eye of the storm) is a clean area where there are no clouds but only light winds.
This area ranges from 10 to 30 km in diameter.
The cloud region lies around this eye and has a diameter of around 150 km.
The cloud region has high-speed winds blowing at 150 to 250 km per hour accompanied by heavy rainfall.
The first indication of a cyclone can be observed when strong winds start flowing and pushing away the water from the shores.
The destruction caused by a cyclone
Cyclone can result in extremely high waves in the sea or ocean because of the low pressure. These waves can be 3 to 12m high.
When these high waves hit the shore it results in the destruction of life and property to a great extent.
The soil of the area also loses its fertility after a cyclone.
Floods can appear if rainfall continues for a longer duration.
High-speed winds in the cyclone affect the telephonic communication lines, uproot trees, damage houses and cause loss of life.
Other names of a cyclone
Hurricane – American continent
Typhoon – Japan and the Philippines
Figure 8 Different types of Cyclones
Tornado
A tornado is a weather condition when a cloud having a dark funnel-shape reaches the ground.
The diameter of a tornado can range from one meter to several kilometres.
The tornadoes can be formed within cyclones as well.
In a tornado, winds blow at high speed of 300 km per hour.
The funnel-like shape of a tornado sucks everything that comes near it at the base because of the low pressure exerted by the winds.
It then throws the things upwards. Hence, tornados can be devastating.
Figure 9 Formation of Tornado
Protecting yourself from a tornado
To protect oneself in a tornado one should take shelter in an underground room with no windows.
If in a room with windows, one should close them and hide under a table or a workbench.
One should bow down on the knees protecting their neck and head using their arms.
Figure 10 Protecting yourself from a tornado
Safety measures for cyclones
There should be a cyclone forecasting service that can want the people of a particular area that can be hit by a cyclone.
The speed of winds plays a major role in predicting any calamity like cyclones hence the speed of wind in coastal areas should be measured regularly. Anemometer is a device that can measure the speed of the Wind.
Figure 11 Anemometer
The warnings should be communicated rapidly to the citizens, ships that are sailing in the sea, government agencies and fisherman as well.
Along with this, cyclone shelters should be built in coastal areas and agencies should be appointed who can help the people at the time of calamity.
How individuals can protect themselves from cyclones
One should not ignore the warnings given by the weather forecasting team. If you can, you must move to safe places and carry all your important belongings with you.
One should not drive on roads that have standing water as they might be damaged.
One should keep all the emergency numbers with themselves so that they can seek help when required.
Figure 12 Protecting yourself during a cyclone
What to do if you are living in a cyclone hit area
The water in such region can be contaminated. Hence one should make sure if the water is safe and only then drink it.
One should stay away from power lines for electrical switches of any kind.
One should stay at home or at the shelters and should not move out unnecessarily.
One should not put unnecessary demands to the rescue team and should co-operate with them.
One should help each other in such a situation.
Role of Technology in predicting and protecting from the cyclone
The satellites and radars have made it possible to predict cyclones ahead of time so that appropriate precautionary measures can be taken accordingly.
There are now several National and international organizations that monitor cyclone-related issues.
Generally, a cyclone watch or a cyclone and alert is issued every 48 hours in advance if a storm is expected in an area.
Then a cyclone warning is issued before 24 hours. This warning is then broadcasted in the area after intervals of half an hour or 1 hour.