1.Give 5 adaptations of the red blood cells
2.give 4 ways in which leucocytes fight infections
3.explain the importance of counter current flow in the fish for gaseous exchange
4.most carbon is transported to the lungs in the red blood cells.Explain the importance of this means
5.state two ways in which a person living in high altitude respond to low oxygen concentration
6.describe how allergic reaction occur
7.give 5 adaptations of the following plants to their environment
a.hydrophytes
b.xerophytes
1. Five adaptations of red blood cells are:
- Biconcave shape: This shape increases the surface area of the cell, allowing for more efficient oxygen and carbon dioxide exchange.
- Lack of nucleus: Without a nucleus, red blood cells can pack more hemoglobin, the molecule responsible for carrying oxygen, and can also fit through narrow capillaries.
- Flexible membrane: The cell membrane of red blood cells is flexible, allowing them to squeeze through narrow blood vessels and transport oxygen to all parts of the body.
- High concentration of hemoglobin: Red blood cells contain a large amount of hemoglobin, which enables them to carry and transport oxygen efficiently.
- Long lifespan: Red blood cells have a lifespan of approximately 120 days, allowing them to continuously transport oxygen and carbon dioxide throughout the body.
2. Four ways in which leucocytes fight infections:
- Phagocytosis: Leucocytes engulf and digest bacteria or other foreign particles.
- Production of antibodies: Leucocytes, especially lymphocytes, produce antibodies that recognize and neutralize specific pathogens.
- Release of cytokines: Leucocytes release cytokines, which are chemical messengers that coordinate the immune response and activate other immune cells.
- Natural killer cells: Some leucocytes, called natural killer cells, can directly kill infected cells by releasing toxic substances.
3. Counter current flow in fish is important for gaseous exchange because it allows for efficient oxygen uptake and carbon dioxide removal in the fish's gills. In counter current flow, the flow of water passes in the opposite direction to the flow of blood in the gill filaments. This setup creates a concentration gradient that maximizes the diffusion of oxygen from the water into the bloodstream and the diffusion of carbon dioxide from the bloodstream into the water. This ensures a high rate of oxygen uptake and efficient removal of carbon dioxide, allowing fish to extract the maximum amount of oxygen from their aquatic environment.
4. The transportation of carbon dioxide to the lungs in red blood cells is important for its removal from the body. Carbon dioxide is produced as a waste product during cellular respiration and needs to be eliminated. Red blood cells transport carbon dioxide in the form of bicarbonate ions (HCO3-) through the blood to the lungs. In the lungs, carbon dioxide is released from the red blood cells and exhaled. This means of transportation allows for the efficient removal of carbon dioxide from tissues and its elimination from the body through exhalation.
5. Two ways in which a person living in high altitude responds to low oxygen concentration are:
- Increased production of red blood cells: In response to low oxygen levels, the body increases the production of red blood cells to enhance oxygen carrying capacity and delivery to tissues.
- Increased breathing rate: To compensate for the reduced oxygen concentration, individuals living at high altitudes tend to breathe at a faster rate and take deeper breaths. This increases the intake of oxygen and helps maintain oxygen levels in the body.
6. Allergic reactions occur when the immune system overreacts to substances that are normally harmless, such as pollen, dust, or certain foods. The steps involved in an allergic reaction are:
- Sensitization: Initial exposure to an allergen triggers the production of antibodies, specifically immunoglobulin E (IgE), which bind to mast cells in tissues.
- Activation: Upon subsequent exposure to the same allergen, the allergen binds to the IgE antibodies on mast cells, causing them to release histamine and other chemicals.
- Inflammation: The released histamine and other chemicals cause inflammation, leading to typical allergic symptoms such as itching, redness, swelling, and increased mucus production.
- Systemic response: In severe allergic reactions, known as anaphylaxis, the release of histamine and other chemicals can lead to a systemic response, causing difficulty in breathing, low blood pressure, and potentially life-threatening symptoms.
7. Adaptations of hydrophytes (water plants):
- Air spaces: Hydrophytes have air spaces in their tissues that allow them to float and stay buoyant.
- Reduced cuticle: Hydrophytes have a thin or absent cuticle on their leaves, which reduces water loss.
- Stomata on the upper leaf surface: Hydrophytes have stomata located on the upper leaf surface to allow easy gas exchange even when submerged in water.
- Floating leaves: Many hydrophytes have leaves that float on the surface of the water to maximize exposure to sunlight for photosynthesis.
- Reduced root system: Hydrophytes often have reduced root systems as they can obtain sufficient nutrients and water directly from their aquatic environment.
Adaptations of xerophytes (desert plants):
- Thick cuticle: Xerophytes have a thick cuticle on their leaves to minimize water loss through transpiration.
- Reduced or absent leaves: Xerophytes may have reduced or modified leaves to decrease the surface area exposed to the sun and reduce water loss.
- Succulent stems/leaves: Some xerophytes have succulent stems or leaves that can store water during periods of drought.
- Deep root system: Xerophytes often have deep root systems to access deeper water sources.
- Hairy/fuzzy leaves: Xerophytes may have hairy or fuzzy leaves to trap moisture and create a microclimate that reduces water loss.
1. Five adaptations of red blood cells are:
- Biconcave shape: The concave shape increases the surface area-to-volume ratio, allowing for more efficient diffusion of gases.
- Lack of nucleus: Without a nucleus, red blood cells have more space to carry oxygen and carbon dioxide.
- Flexible membrane: The flexible membrane allows red blood cells to squeeze through narrow capillaries and transport oxygen to tissues.
- High concentration of hemoglobin: Hemoglobin binds to oxygen in the lungs and releases it in tissues, ensuring efficient oxygen transport.
- Long lifespan: Red blood cells live for about 120 days, allowing for continuous oxygen and carbon dioxide transport.
2. Four ways in which leukocytes fight infections are:
- Phagocytosis: Leukocytes engulf and digest harmful microorganisms through the process of phagocytosis.
- Production of antibodies: Some leukocytes, such as B lymphocytes, produce antibodies that target specific pathogens.
- Release of cytokines: Leukocytes release cytokines, which are chemical messengers that help coordinate the immune response and attract other leukocytes to the site of infection.
- Destruction of infected cells: Certain leukocytes, like natural killer (NK) cells, can recognize infected cells and induce their death to prevent further spread of infection.
3. Counter current flow is important in fish for gaseous exchange because it maximizes the diffusion of gases (oxygen and carbon dioxide) across the gills. In counter current flow, water flows across the gills in one direction while blood flows in the opposite direction. This creates a concentration gradient where the oxygen content of the water is always higher than the oxygen content in the blood. Similarly, the carbon dioxide content of the blood is always higher than that in the water. As a result, there is a continuous diffusion of oxygen into the blood and diffusion of carbon dioxide out of the blood, ensuring efficient exchange of gases.
4. Most carbon dioxide is transported to the lungs in red blood cells in the form of bicarbonate ions (HCO3-). This transport mechanism is important because it allows for efficient removal of carbon dioxide from tissues and its elimination from the body through exhalation. Carbon dioxide produced by cells diffuses into red blood cells and reacts with water to form carbonic acid (H2CO3), which quickly dissociates into bicarbonate ions and hydrogen ions. Bicarbonate ions are then transported in the blood plasma, while hydrogen ions bind to hemoglobin. At the lungs, the reverse reaction occurs, with bicarbonate ions converting back into carbon dioxide, which can be exhaled.
5. Two ways a person living in high altitude responds to low oxygen concentration are:
- Increased breathing rate: Living at high altitude stimulates the respiratory system to increase the rate and depth of breathing. This helps to bring in more oxygen and remove carbon dioxide from the body.
- Increased production of red blood cells: Low oxygen concentration triggers the release of a hormone called erythropoietin, which stimulates the production of red blood cells in the bone marrow. This increases the oxygen-carrying capacity of the blood.
6. Allergic reactions occur when the immune system overreacts to harmless substances called allergens. The steps involved in an allergic reaction are as follows:
- Sensitization: Upon initial exposure to an allergen, the immune system recognizes it as foreign and initiates an immune response. B cells produce IgE antibodies specific to the allergen.
- Re-exposure: If the individual is re-exposed to the same allergen, it binds to the IgE antibodies on mast cells and basophils.
- Release of histamine: The binding of allergen to IgE antibodies triggers the release of histamine and other inflammatory chemicals from mast cells and basophils.
- Inflammatory response: Histamine causes blood vessels to dilate, leading to increased blood flow and capillary permeability. This results in the typical symptoms of an allergic reaction, such as redness, itchiness, and swelling.
- Activation of other immune cells: The release of histamine also attracts other immune cells, such as eosinophils and neutrophils, to the site of the allergic reaction. These immune cells release further chemicals that contribute to the allergic response.
7. Adaptations of plants to their environment vary depending on their habitats. Here are five adaptations for hydrophytes (plants adapted to water environments) and xerophytes (plants adapted to dry environments):
a. Hydrophytes:
- Reduced or absent cuticle: Hydrophytes often have a thin or absent cuticle, allowing for increased uptake of water from the surrounding environment.
- Air-filled tissues: Some hydrophytes have air spaces in their tissues that aid buoyancy and provide oxygen for submerged parts.
- Reduced and flexible stems: Hydrophytes usually have flexible stems to withstand water movement and prevent breaking.
- Reduced root development: Hydrophytes may have reduced root systems, as they can absorb nutrients directly from the water.
- Wide and flat leaves: Leaves of hydrophytes are often flat and wide to maximize the surface area for capturing sunlight and exchanging gases with water.
b. Xerophytes:
- Thick cuticle: Xerophytes often have a thick cuticle to reduce water loss through evaporation.
- Reduced leaf surface area: Xerophytes may have reduced leaf size or spines to minimize water loss through transpiration.
- Succulent stems or leaves: Some xerophytes have succulent stems or leaves that can store water for prolonged periods of time.
- Deep root systems: Xerophytes often have deep root systems to access water at lower soil levels.
- CAM photosynthesis: Some xerophytes use Crassulacean Acid Metabolism (CAM) photosynthesis, which allows them to open their stomata at night to reduce water loss during the day.