Biology Exam 4-part2 Ch21

Vegetarians who rely upon a single type of plant food may become protein-deficient. This is because different plant foods contain different types and amounts of proteins, and relying on only one type may not provide all the essential amino acids that the body needs. Protein deficiency can lead to various health issues such as muscle weakness, fatigue, and impaired immune function. Therefore, it is important for vegetarians to consume a variety of plant-based protein sources to ensure they meet their protein requirements.

Bile produced in the liver is stored in the gallbladder before entering the intestine. The gallbladder acts as a storage organ for bile, which is a fluid that helps in the digestion and absorption of fats. When food enters the small intestine, the gallbladder contracts and releases bile into the common bile duct, which then transports it to the intestine. This allows the bile to mix with the food and aid in the breakdown and absorption of fats.

Cardiovascular disease is associated with obesity because excess weight can lead to various risk factors such as high blood pressure, high cholesterol levels, and diabetes, which in turn increase the chances of developing cardiovascular diseases such as heart disease and stroke. Obesity puts extra strain on the heart and blood vessels, leading to inflammation and the accumulation of fatty deposits, which can ultimately result in cardiovascular problems.

The absorption of water is a major function of the colon. The colon is the final segment of the digestive system, responsible for reabsorbing water and electrolytes from undigested food material before it is eliminated as waste. This process helps in maintaining the body's fluid balance and preventing dehydration. The other options listed, such as the esophagus, cecum, appendix, and rectum, do not play a significant role in water absorption.

A diet high in antioxidants has been suggested to reduce the risk of cancer. Antioxidants help to neutralize free radicals in the body, which can cause damage to cells and potentially lead to cancer. By consuming foods rich in antioxidants, such as fruits, vegetables, and certain nuts, individuals may be able to protect their cells from this damage and lower their risk of developing cancer.

When we chew bread in our mouth, the amylase enzyme present in saliva starts breaking down the starch present in the bread into simpler sugars, such as glucose. This conversion of starch into glucose gives the bread a sweet taste.

Organisms suffering from malnourishment have a diet deficient in one or more essential nutrients. Malnourishment refers to the condition where an organism does not receive enough nutrients to maintain proper health and functioning. Essential nutrients are substances that the body needs but cannot produce on its own, such as vitamins, minerals, and certain amino acids. When an organism lacks these essential nutrients, it can lead to various health problems and deficiencies. Therefore, the correct answer is that malnourished organisms have a diet deficient in one or more essential nutrients.

Metabolic rate refers to the rate at which the body consumes or uses energy. It is a measure of how quickly the body converts food into energy for various bodily functions. This includes processes such as digestion, absorption, and transportation of nutrients, as well as the functioning of organs and muscles. Metabolic rate can be influenced by factors such as age, sex, body size, and physical activity level. It is an important factor to consider when evaluating an individual's overall energy balance and can impact weight management and overall health.

Rabbits have a simple stomach and a large cecum, which is responsible for further digestion of their food. The cecum contains beneficial bacteria that help break down cellulose and other complex carbohydrates. When rabbits eliminate their feces, they are actually expelling partially digested food from their cecum, which still contains a significant amount of nutrients. By consuming these feces, known as cecotropes, rabbits are able to reabsorb these nutrients and maximize their nutritional intake.

Fat is the correct answer because it is the only nutrient that is primarily digested in the small intestines. When fat reaches the small intestines, it is broken down into smaller molecules called fatty acids and glycerol by enzymes called lipases. These smaller molecules are then absorbed into the bloodstream and transported to cells throughout the body for energy production and other functions. In contrast, protein and complex carbohydrates are digested and broken down into smaller molecules in the stomach and small intestines before being absorbed into the bloodstream.

Vitamin K is the correct answer because it is a fat-soluble vitamin, which means it can dissolve in and be stored in body fat. Fat-soluble vitamins are absorbed through the intestinal tract with the help of fats and are stored in the liver and fatty tissues until the body needs them. Pyridoxine, pantothenic acid, biotin, and niacin are all water-soluble vitamins, which means they dissolve in water and are not stored in the body.

The liver plays a crucial role in regulating blood glucose levels. When there is an excess of glucose in the bloodstream, the liver converts it into glycogen, which is a storage form of glucose. This conversion helps to maintain stable blood sugar levels by storing the excess glucose for later use. Glycogen can be broken down back into glucose when the body needs energy. This process allows the liver to manage the amount of glucose in the bloodstream and prevent it from reaching harmful levels.

The lion's evolutionary adaptation of an expandable stomach helps it survive periods of famine. This allows the lion to consume a large amount of food in one sitting and store it in its stomach for later use. By being able to eat a large meal and then go days between meals, the lion can endure periods of scarcity and still maintain its energy levels.

Appendicitis is the correct answer because it refers to the inflammation of the appendix, which is located at the junction of the small and large intestine. The other options, such as gastric ulcer, constipation, heartburn, and diarrhea, are not specifically related to the inflammation of this particular area in the digestive system.

Meat is not more difficult to digest than vegetable matter because of its protein content. In fact, protein digestion is generally easier for animals compared to cellulose digestion. Herbivores have specialized digestive systems that allow them to break down cellulose with the help of cellulose-digesting microbes in their colon and cecum. Additionally, the statement about herbivores having a longer alimentary canal than carnivores is true because plant material takes longer to digest. Rumination, the process of regurgitating and re-chewing food, helps herbivores soften and break down plant fibers, aiding in digestion. Therefore, the false statement is that meat is more difficult to digest due to its protein content.

Vitamins can serve as coenzymes or parts of coenzymes. Coenzymes are molecules that work together with enzymes to facilitate and regulate biochemical reactions in the body. Vitamins, such as vitamin B complex and vitamin C, play essential roles in the functioning of coenzymes. They act as cofactors or precursors for coenzymes, helping enzymes to catalyze reactions and perform their biological functions. This statement is true as it highlights the important role of vitamins in the coenzyme system.

Emulsification is the process of breaking down large fat molecules into smaller droplets, allowing them to mix with water. This process is essential for the digestion and absorption of fats in the body. Lipase is an enzyme that helps in the breakdown of fats, while peristalsis is the muscular contraction that propels food through the digestive system. Fatty acids and glycerol are the end products of fat digestion, not the process itself. Therefore, the correct answer is emulsification.

In the stomach, the enzyme pepsinogen is converted to pepsin in the presence of hydrochloric acid (HCL). This conversion is important for the digestion of proteins. Pepsin is an active form of the enzyme that can break down proteins into smaller peptides. HCL provides the acidic environment necessary for the activation of pepsinogen into pepsin. Therefore, the correct answer is "Pepsiogen, pepsin, HCL."

Lipase is the enzyme that converts fat into fatty acids and glycerol. Pepsin is the enzyme that converts proteins into amino acids. Amylase is the enzyme that converts polysaccharides (complex carbohydrates) into glucose. However, amylase does not convert lipids (fats) into fatty acids and glycerol.

The liver does not secrete insulin. Insulin is primarily produced and secreted by the pancreas. It plays a crucial role in regulating blood sugar levels by facilitating the uptake of glucose into cells. The liver, on the other hand, has various functions such as producing bile juice, converting glucose to glycogen for storage, and converting toxic ammonia into urea for excretion.

If a person on a fad diet experiences muscle cramps and reduced appetite, a physician would suspect that this individual is likely suffering from a deficiency of table salt. This is because table salt, or sodium chloride, is essential for maintaining proper fluid balance and nerve function in the body. A deficiency in table salt can lead to electrolyte imbalances, which can cause muscle cramps and a reduced appetite.

The formation of pepsin in the stomach is an example of a positive feedback mechanism. Pepsin is an enzyme that helps break down proteins in the stomach. When pepsin is released and starts breaking down proteins, it also triggers the release of more pepsin. This creates a cycle where the more pepsin that is produced, the more it stimulates its own production. This positive feedback loop continues until all the proteins are broken down.

Herbivorous animals have evolved a mechanism of digestion by symbiotic microorganisms to survive despite their inability to digest cellulose. These microorganisms reside in the digestive system of these animals and break down the cellulose into other carbohydrates that can be easily digested by the animals. This symbiotic relationship allows herbivorous animals to obtain nutrients from plant matter and survive on a diet consisting solely of plants.

Essential fatty acids are those fatty acids that cannot be synthesized by the human body and must be obtained through the diet. They play important roles in various physiological processes and are necessary for the synthesis of certain hormones and cell membranes. Therefore, the correct answer is "those fatty acids that humans are unable to synthesize."