Transportation In Plants And Animals

CloseRed blood cells contain a special protein called hemoglobin, which binds to oxygen in the lungs. As blood circulates, hemoglobin releases this oxygen to all the cells in the body, which need oxygen to produce energy. Without red blood cells, oxygen transport would not be efficient.

CloseArteries are thick-walled blood vessels designed to carry oxygen-rich blood from the heart to the rest of the body under high pressure. Veins carry blood back to the heart, and capillaries are tiny vessels where exchange of materials occurs.

ClosePlatelets are small, disc-shaped cell fragments in blood. When a blood vessel is injured, platelets gather at the site, stick together, and release chemicals that start the clotting process. This prevents excessive bleeding and helps in wound healing.

CloseXylem is a vascular tissue in plants consisting of dead cells arranged as long tubes. It carries water and dissolved minerals from the roots upward to the stems and leaves. The movement occurs through transpiration pull and root pressure.

ClosePhloem is a living vascular tissue that transports the sugar (food) made in leaves during photosynthesis to all other parts of the plant like roots, stems, and fruits. This process is called translocation and requires energy.

CloseAmoeba is a unicellular organism. It does not need a circulatory system because its entire body surface is in direct contact with the environment. Diffusion across the cell membrane transports oxygen, nutrients, and waste products efficiently.

CloseTranspiration is the loss of water vapor mainly through tiny pores called stomata on leaves. This process helps in cooling the plant, creates a suction force for water uptake, and helps in mineral transport.

CloseThe right ventricle receives deoxygenated blood from the right atrium and pumps it to the lungs through the pulmonary artery. In the lungs, carbon dioxide is removed and oxygen is added to the blood.

CloseDiffusion is a passive process where molecules move randomly from an area where they are more crowded to an area where they are less crowded until evenly distributed. It does not require energy and is important in gas exchange in unicellular organisms and plants.

CloseOsmosis is the special type of diffusion of water across a semipermeable membrane. The cell sap in root hairs has a higher concentration of solutes than the surrounding soil water, so water moves into the root hairs by osmosis.

CloseUnicellular organisms like Paramecium and Amoeba have a large surface area to volume ratio. Diffusion across the cell membrane allows oxygen to enter, carbon dioxide and wastes to leave quickly without needing any circulatory system.

CloseCapillaries have walls that are only one cell thick. This thinness allows for easy exchange of oxygen, carbon dioxide, nutrients, and wastes between blood and body tissues. Arteries and veins have thicker walls to withstand pressure or prevent backflow.

CloseAs water evaporates from leaves during transpiration, it creates a negative pressure or suction. This transpiration pull pulls water upward through the xylem tubes from roots to leaves. Root pressure also helps but is weaker and works mainly at night.

CloseThe pulmonary vein is unique because it carries oxygenated blood. After blood gets oxygen in the lungs, the pulmonary vein transports it to the left atrium of the heart. Most other veins carry deoxygenated blood.

CloseXylem and phloem are the two types of vascular tissues in plants. They form continuous conducting systems throughout the plant. Xylem transports water and minerals, while phloem transports food. Together they are called vascular bundles.

CloseTranspiration is water loss, not carbon dioxide entry. Carbon dioxide enters leaves through the same stomata but is not a function of transpiration. The other options are correct: transpiration cools leaves, pulls water up, and helps mineral movement.

ClosePlasma is the yellowish liquid matrix of blood, making up about 55% of blood volume. It is 90-92% water and contains dissolved nutrients, salts, hormones, proteins, and waste products like urea. It helps in transport and maintaining blood pressure.

CloseSimple multicellular plants such as filamentous algae (Spirogyra) have a simple body plan without true vascular tissues. They are thin and live in water, so each cell is close to the environment, allowing diffusion and osmosis to handle transport of materials.

CloseThe heartbeat is the sequence of contraction (systole) and relaxation (diastole) of the heart chambers. It pumps blood throughout the body. The average resting heartbeat in humans is 60-100 beats per minute. Each beat can be felt as a pulse in arteries.

CloseStomata are small openings mainly on the underside of leaves. Each stoma is surrounded by guard cells that open and close to regulate water loss and gas exchange. Most transpiration (about 90%) occurs through stomata.

CloseIn double circulation, blood passes through the heart twice. First, deoxygenated blood goes from heart to lungs (pulmonary circulation), returns to heart, then is pumped to body (systemic circulation), and returns again to heart.

CloseTracheids and vessel elements are the main water-conducting cells in xylem. They are dead when mature, meaning they are hollow tubes. Their walls are thickened with lignin, which provides strength and prevents collapse under tension.

CloseActive transport requires energy (ATP) to move substances against a concentration gradient. Root hairs actively pump mineral ions from soil (low concentration) into the root cells (higher concentration) because minerals are needed in larger amounts inside.

ClosePhloem transports food (sucrose and amino acids) from source (leaves) to sink (roots, fruits, growing tips). Food can move upward to growing shoots or downward to roots depending on where energy is needed. This two-way movement is called translocation.

CloseThe tricuspid valve has three flaps and prevents backflow of blood from the right ventricle into the right atrium when the ventricle contracts. The bicuspid (mitral) valve is on the left side. Valves ensure one-way flow of blood.

CloseTranspiration rate increases with high temperature (increases evaporation), wind (removes water vapor near leaf surface), and sunlight (opens stomata). A sunflower on a hot windy day loses water rapidly. Cactus has adaptations to reduce transpiration.

CloseBlood carries two major wastes: carbon dioxide (from cellular respiration) to lungs for exhalation, and urea (from protein breakdown) to kidneys for urine formation. Other wastes like excess water and salts are also transported.

CloseAccording to the pressure flow hypothesis, sugar is loaded into phloem at the source (leaves), making water enter by osmosis, creating high pressure. At the sink (roots/fruits), sugar is unloaded, water leaves, lowering pressure. Flow occurs from high to low pressure.

CloseParamecium is a unicellular organism covered with tiny hair-like structures called cilia. Beating of cilia creates water currents that sweep food particles and oxygen toward the cell mouth. Diffusion then transports materials across the cell membrane.

CloseHemoglobin is an iron-containing protein in red blood cells. Each hemoglobin molecule can bind four oxygen molecules, forming oxyhemoglobin. This reversible binding allows efficient oxygen pickup in lungs and release in tissues. It also gives blood its red color.

CloseVeins carry blood back to the heart under low pressure. To prevent gravity from pulling blood backward, especially in legs, veins contain one-way valves. Most veins carry deoxygenated blood, except pulmonary veins which carry oxygenated blood.

CloseGuttation occurs at night or early morning when humidity is high and transpiration is low. Root pressure forces liquid water out through special pores called hydathodes at leaf tips and edges, forming droplets. Unlike transpiration (vapor), guttation is liquid water.

CloseBlood transports oxygen, carbon dioxide, digested food (glucose, amino acids), hormones, waste products, and heat. Sunlight is not a substance carried by blood; it is light energy that plants use for photosynthesis but animals do not transport it in blood.

CloseHibiscus is a flowering plant with well-developed vascular tissue. Xylem forms continuous tubes from root hairs to leaf veins, carrying water and dissolved minerals upward. Without xylem, the plant cannot replace water lost by transpiration and will wilt.

ClosePlatelets immediately stick to the injured site and release clotting factors. These factors convert fibrinogen (soluble protein in plasma) into fibrin (insoluble threads). Fibrin forms a mesh that traps red blood cells, creating a clot to seal the wound.

CloseSpirogyra is a filamentous alga. Its cells are arranged end to end, but there are no specialized conducting tissues. Materials move by diffusion across cell walls and through cytoplasmic connections called plasmodesmata. The thinness of the filament makes diffusion efficient.

CloseThe aorta is the main artery arising from the left ventricle. It is about 3-4 cm in diameter. It carries oxygenated blood to all parts of the body except the lungs. It branches into smaller arteries like the carotid (to head) and femoral (to legs).

CloseDesert plants (xerophytes) conserve water. They have a thick waxy cuticle to reduce evaporation, stomata sunken in pits to trap moist air, reduced leaf size (spines in cactus), and often open stomata only at night to minimize water loss.

CloseSystolic pressure is the higher number in a blood pressure reading (e.g., 120/80). It measures pressure in arteries when the heart’s ventricles contract and push blood out. Diastolic pressure is the lower number, measured when the heart relaxes between beats.

CloseSoil usually has fewer mineral ions than the inside of root hair cells. To absorb minerals, the plant must move them against the concentration gradient (from low to high). This requires energy in the form of ATP through active transport.

CloseDiffusion occurs in gases, liquids, and solids (though very slow in solids). For example, perfume diffuses through air (gas), sugar diffuses through water (liquid). The statement is false because diffusion is not restricted to liquids only.

CloseLignin is a complex polymer deposited in the cell walls of xylem vessels and tracheids. It provides mechanical strength to withstand the tension of water column and makes walls waterproof to prevent water leakage. It also causes the cells to be dead at maturity.

CloseDiffusion rate increases with temperature and short distance. A single-celled alga has a very short diffusion distance (across cell membrane). Warm water provides kinetic energy to molecules. The other options involve thick barriers or dry surfaces slowing diffusion.

CloseWhite blood cells (leukocytes) are part of the immune system. They can engulf bacteria (phagocytosis), produce antibodies, and destroy infected or cancerous cells. They are much fewer in number than red blood cells but are essential for defense against diseases.

CloseCohesion (water molecules stick to each other by hydrogen bonds) forms a continuous water column. Adhesion (water sticks to xylem walls) prevents the column from slipping. Together they maintain the unbroken water column from roots to leaves under tension.

CloseXylem transports water and dissolved minerals upward. Phloem transports food (sugars and amino acids) both upward and downward. The other options reverse the functions incorrectly.

CloseThe human heart has four chambers: two upper atria (singular: atrium) and two lower ventricles. The right atrium receives deoxygenated blood from the body, and the left atrium receives oxygenated blood from the lungs. Atria pump blood into ventricles.

CloseThe phrase “necessary evil” means transpiration is harmful because it wastes water (up to 99% of absorbed water is lost), but it is necessary because it creates transpiration pull for water and mineral uptake and cools leaves. The benefits outweigh the cost.

CloseOsmosis is a special case of diffusion where only water moves across a selectively permeable membrane. Water moves from a region of high water concentration (low solute) to low water concentration (high solute). It is passive and does not require energy.

CloseDeoxygenated blood from the body enters the right atrium through the vena cava. It then passes into the right ventricle, which contracts and pumps blood into the pulmonary artery. The pulmonary artery carries blood to the lungs for oxygenation. This is the pulmonary circulation pathway.