Digestive System Overview

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What is a common evidence for being alive according to the text?

Sleeping

Breathing

Visible movement (correct)

Eating

Why do some people think plants are alive?

They grow over time (correct)

They are green

They are stationary

They have colorful leaves

What characteristic of life is NOT solely based on visible movement according to the text?

Breathing

Sleeping (correct)

Eating

Growth

Why is there controversy about whether viruses are truly alive?

They lack molecular movement Signup and view all the answers

What kind of movement is mentioned as invisible but necessary for life by professional biologists?

Molecular movements Signup and view all the answers

Why is it mentioned that a plant that is not visibly growing is still alive?

It grows over time Signup and view all the answers

What is the main function of peristaltic movements in the digestive tube?

Regulate the movement of food along the digestive tube Signup and view all the answers

How does the stomach expand when food enters it?

By contracting its walls rhythmically Signup and view all the answers

What is the role of gastric glands in the stomach?

Create an acidic medium for enzyme action Signup and view all the answers

How does dental caries or tooth decay begin?

By softening or demineralising enamel Signup and view all the answers

What is the function of mucus in the stomach?

Protect the inner lining from acid action Signup and view all the answers

Which enzyme is responsible for protein digestion in the stomach?

Pepsin Signup and view all the answers

What is the function of chloroplasts in a leaf cell?

Converting light energy into chemical energy Signup and view all the answers

What is the purpose of keeping a potted plant with variegated leaves in a dark room for three days before conducting the activity?

To ensure all the starch in the leaves gets used up Signup and view all the answers

What is the purpose of dipping the leaf in boiling water and then immersing it in alcohol during the activity?

To prepare the leaf for iodine staining Signup and view all the answers

What does boiling alcohol in a water bath after immersing the leaf help achieve?

Removing excess alcohol from the leaf Signup and view all the answers

What conclusion can be drawn if after iodine staining, green areas on the leaf turn blue-black?

There is no starch present in those areas Signup and view all the answers

How does keeping a potted plant with variegated leaves in sunlight for six hours help demonstrate the role of chlorophyll in photosynthesis?

It promotes chlorophyll synthesis and thus starch production Signup and view all the answers

Where does the breakdown of glucose into pyruvate take place?

Cytoplasm Signup and view all the answers

Which molecule is formed by the breakdown of pyruvate in yeast during fermentation?

Ethanol Signup and view all the answers

What is the term used for the process of breaking down pyruvate into lactic acid when oxygen is lacking in muscle cells?

Anaerobic respiration Signup and view all the answers

In which organelle does the breakdown of pyruvate into carbon dioxide take place using oxygen?

Mitochondria Signup and view all the answers

Which type of respiration releases a greater amount of energy, aerobic or anaerobic?

Aerobic respiration Signup and view all the answers

What causes muscle cramps during sudden activity due to the build-up of lactic acid?

Build-up of lactic acid Signup and view all the answers

Why is it important to brush teeth after eating?

To remove plaque before bacteria produce acids Signup and view all the answers

Which part of the alimentary canal is the longest?

Small intestine Signup and view all the answers

Why do herbivores need a longer small intestine compared to carnivores?

To allow cellulose digestion Signup and view all the answers

What is the role of bile juice from the liver in digestion?

Emulsifying fats Signup and view all the answers

Why does the food coming from the stomach need to be made alkaline in the small intestine?

To facilitate pancreatic enzyme activity Signup and view all the answers