organelles

Functions of Organelles:

  1. What is the main function of the nucleus?
     Answer: The nucleus controls cell activities by storing the cell’s genetic material (DNA) and directing protein synthesis.

  2. What is the role of mitochondria?
     Answer: Mitochondria generate energy (ATP) through cellular respiration, making them the "powerhouse" of the cell.

  3. What is the function of chloroplasts in plant cells?
     Answer: Chloroplasts carry out photosynthesis, converting sunlight into chemical energy stored as glucose.

  4. What does the Golgi apparatus do?
     Answer: The Golgi apparatus modifies, sorts, and packages proteins and lipids for transport within or outside the cell.

  5. How do lysosomes function in animal cells?
     Answer: Lysosomes break down waste materials and cellular debris, acting as the cell's "recycling center."

Cell Theory:

  1. What are the three main parts of cell theory?
     Answer:

    • All living things are made of cells.

    • Cells are the basic unit of structure and function in living organisms.

    • All cells come from pre-existing cells.

  2. Who first discovered cells?
     Answer: Robert Hooke first discovered cells in 1665 when observing cork under a microscope.

  3. According to cell theory, where do new cells come from?
     Answer: New cells arise from the division of pre-existing cells.

Macromolecules 

  1. Is the primary function of carbohydrates in the human body?

  • Provide short term and long term energy storage for organisms 

  • Provide materials to build cell membrane 

  1. Difference between a monosaccharide and a disaccharide. Give an example of each.

  • An example of monosaccharides are glucose and fructose.

  • An example of disaccharides are sucrose and maltose.And lactose. 

  1. Explain how macromolecules are broken down for using the body.

  • Are broken by chemical breakdown called hydrolysis.

  • A water molecule was added to the macromolecule.

  • Breaks the chemical bonds that hold together the smaller molecules. 

  1.  If an athlete runs for 15 minutes, which macromolecules are likely to break down first in the athlete's body?

  • Carbohydrates 

  1. Which macromolecules would provide the greatest benefit as a long term energy storage molecule to a bird that migrates long distances?

  • Lipids 

  1. Name three of the functions of proteins in the human body. 

  • Aid in muscle contraction

  • Provide immunity against infection and disease 

  • Provide structure and support for blood cells, body tissues, and muscles 

Here are the answers to your questions on the Digestive System Structures and Circulatory System Functions:

Digestive System Structures:

  1. What is an esophagus?
     Answer: The esophagus is a muscular tube that connects the throat (pharynx) to the stomach, allowing the passage of food and liquids.

  2. What is peristalsis?
     Answer: Peristalsis is the rhythmic contraction and relaxation of muscles in the esophagus and intestines, moving food through the digestive system.

  3. What are gastric juices?
     Answer: Gastric juices are a mixture of hydrochloric acid, digestive enzymes, and mucus secreted by the stomach, which helps break down food.

  4. What is chyme and pepsin?
     Answer:

    • Chyme is the semi-liquid mass of partly digested food that moves from the stomach to the small intestine.

    • Pepsin is a digestive enzyme in the stomach that breaks down proteins into smaller peptides.

  5. What is the duodenum?
     Answer: The duodenum is the first section of the small intestine, where most chemical digestion occurs, receiving bile from the liver and pancreatic enzymes.

  6. What is the villi?
     Answer: Villi are small, finger-like projections in the lining of the small intestine that increase surface area for absorption of nutrients.

  7. What is the jejunum and the ileum?
     Answer: The jejunum is the middle section of the small intestine responsible for nutrient absorption. The ileum is the final section, absorbing remaining nutrients and bile salts.

  8. What is bile?
     Answer: Bile is a digestive fluid produced by the liver and stored in the gallbladder. It helps break down fats into smaller molecules during digestion.

  9. What are the accessory organs?
     Answer: The accessory organs are the liver, pancreas, and gallbladder. These organs assist digestion but food does not pass through them directly.

  10. Explain 2 functions of pancreatic fluid.
     Answer:

    • Pancreatic fluid contains enzymes that help digest carbohydrates, proteins, and fats.

    • It also contains bicarbonate, which neutralizes stomach acid entering the small intestine.

  11. What happens to fats before they are digested and absorbed by intestinal cells? Explain why this occurs.
     Answer: Fats are emulsified by bile salts into smaller droplets, increasing surface area for the enzyme lipase to break them down. This aids in digestion and absorption.

  12. What is the role of the gallbladder in digestion?
     Answer: The gallbladder stores and concentrates bile, releasing it into the small intestine to help digest fats.

  13. Why would the removal of the gallbladder cause diarrhea?
     Answer: Without a gallbladder, bile is continuously released into the intestines, which can lead to improper fat digestion, causing diarrhea.

  14. Describe one possible consequence of fewer villi in the small intestine due to mutation.
     Answer: Reduced villi would decrease the surface area for nutrient absorption, leading to malnutrition and slower growth in the affected individual.

Circulatory System Functions:

  1. What are the main functions of the circulatory system?
     Answer: The circulatory system transports oxygen, nutrients, hormones, and waste products throughout the body and helps regulate body temperature.

  2. What are the main components of the circulatory system?
     Answer: The heart, blood, and blood vessels (arteries, veins, and capillaries).

  3. Two types of circulatory systems?
     Answer:

    • Open circulatory system (invertebrates like insects): blood (hemolymph) flows freely in body cavities.

    • Closed circulatory system (vertebrates): blood flows within vessels, separated from body tissues.

  4. Explain the four chambers of the heart.
     Answer:

    • Right atrium: receives deoxygenated blood from the body.

    • Right ventricle: pumps deoxygenated blood to the lungs.

    • Left atrium: receives oxygenated blood from the lungs.

    • Left ventricle: pumps oxygenated blood to the body.

  5. Explain how hemolymph in an open circulatory system moves through its body.
     Answer: Hemolymph is pumped by the heart into open spaces (hemocoel), where it bathes organs directly, and then returns to the heart.

  6. Describe the destination of the blood leaving each of the four chambers of the heart.
     Answer:

    • Right atrium → right ventricle → lungs (via pulmonary arteries).

    • Left atrium → left ventricle → body (via aorta).

    • Right ventricle → lungs.

    • Left ventricle → body.

  7. Describe arteries, veins, and capillaries.
     Answer:

    • Arteries carry blood away from the heart.

    • Veins carry blood to the heart.

    • Capillaries connect arteries and veins, allowing for exchange of gases, nutrients, and waste.

  8. Is there a difference between pulmonary circulation and systemic circulation?
     Answer: Yes, pulmonary circulation involves blood flow between the heart and lungs, while systemic circulation involves blood flow between the heart and the rest of the body.

  9. What is plasma?
     Answer: Plasma is the liquid component of blood, containing water, proteins, electrolytes, and nutrients.

  10. What are white blood cells and their functions?
     Answer: White blood cells (leukocytes) are immune cells that fight infections and protect the body against foreign invaders.

  11. Do all arteries carry oxygen-rich blood and all veins carry oxygen-poor blood?
     Answer: No. Pulmonary arteries carry oxygen-poor blood to the lungs, and pulmonary veins carry oxygen-rich blood to the heart.

  12. Provide details about the three main components of blood.
     Answer:

    • Red blood cells (erythrocytes): carry oxygen to body tissues.

    • White blood cells (leukocytes): fight infections.

    • Platelets (thrombocytes): help in blood clotting.

  13. Predict what might happen if the AV node does not receive a signal from the SA node.
     Answer: If the AV node doesn't receive the signal, the ventricles may not contract properly, leading to an irregular or slow heartbeat.

  14. What 3 characteristics of a heartbeat can be determined by examining an ECG?
     Answer:

    • Heart rate (beats per minute).

    • Heart rhythm (regular or irregular).

    • Electrical activity of the heart (presence of abnormalities).

  15. Suggest two parts of the body where blood usually loses heat, and one part of the body where blood gains heat.
     Answer:

    • Loses heat: Hands, feet.

    • Gains heat: Core areas like the abdomen (due to organ activity).