Biology Quiz on Living Organisms and Cells

The ability of living organisms to detect and respond to changes in their environment.

The process by which organisms take in nutrients to provide energy and materials for growth and development.

The removal of waste products from an organism's body.

The production of offspring by living organisms.

The permanent increase in size or cell number of an organism.

The movement of molecules from a region of high concentration to a region of low concentration.

The movement of water molecules across a semi-permeable membrane from a region of high water concentration to a region of low water concentration.

The ratio of the size of an image to the actual size of the object being viewed.

A difference in concentration between two areas.

The ability of a cell membrane to let some substances pass through while blocking others.

The pressure exerted by water against the cell wall in a plant cell.

A solution with a lower solute concentration than inside the cell.

A solution with a higher solute concentration than inside the cell.

The process by which cells specialize to perform specific functions.

The basic building blocks of all living things.

Groups of similar cells that work together to perform a specific function.

Groups of tissues that work together to perform a specific function.

Groups of organs that work together to perform a specific function.

A complete living thing made up of organ systems.

Transport oxygen throughout the body.

Found in the lining of the nose and windpipe, they sweep mucus and dust out of the airways.

The process of breathing, which involves the movement of air into and out of the lungs.

The process of air being drawn into the lungs when the diaphragm contracts and the rib muscles expand the chest cavity.

The process of air being expelled from the lungs when the diaphragm relaxes and the rib muscles contract, reducing the chest cavity size.

The process by which cells use oxygen to break down glucose and release energy. It occurs within the cells themselves.

The process by which cells use oxygen to break down glucose and release energy. It occurs in the presence of oxygen.

The process of glucose being partially broken down in the absence of oxygen, yielding less energy than aerobic respiration.

A diet that provides all the necessary nutrients in the right amount for optimal health.

Provide energy. Sources include grains, fruits, and vegetables.

Provide energy and essential fatty acids. Sources include oils, nuts, and seeds.

Build and repair tissues. Sources include meat, beans, and dairy.

Essential for various body functions. Sources include citrus fruits.

Essential for various body functions. Sources include sunlight and fortified foods.

Essential for various body functions. Sources include dairy and leafy greens.

Essential for various body functions. Sources include meat and leafy greens.

Aids digestion. Sources include fruits, vegetables, and whole grains.

Biological catalysts that speed up chemical reactions without being used up themselves. They have a specific shape that allows them to bind to a specific molecule called a substrate.

The primary organs for gas exchange in humans, where oxygen enters the blood and carbon dioxide leaves the blood.

Tiny air sacs in the lungs where gas exchange occurs. They have a large surface area and thin walls, facilitating diffusion of gases.

The process of getting oxygen from the air into the body and removing carbon dioxide.

The range of pH values at which an enzyme functions optimally. Changes in pH can alter the enzyme's shape and affect its ability to bind to the substrate.

The point at which an enzyme's activity is highest, often related to a specific temperature or pH.

The process of an enzyme losing its shape and becoming inactive, often caused by extreme temperatures or pH changes.

The effect of temperature on enzyme activity. Enzyme activity generally increases with temperature due to increased kinetic energy of molecules, but high temperatures can denature enzymes.

The effect of pH on enzyme activity. Enzymes have an optimal pH range. Changes in pH can alter the enzyme's shape and affect its ability to bind to the substrate.

The process of breaking down food into smaller molecules that can be absorbed by the body.

Inorganic substances essential for various bodily functions. Obtained from a variety of food sources.

Essential for all body functions, including transporting nutrients, regulating body temperature, and removing waste products.

The condition of having excess body fat. Caused by consuming more calories than the body needs.

The process of the body not receiving enough energy from food, leading to the breakdown of body tissues for fuel.

A condition resulting from inadequate intake of specific nutrients, leading to health problems.

Pregnant women require increased intake of protein, calcium, iron, vitamin D, and folic acid to support the growth and development of the fetus.

Lactating mothers require increased intake of protein, calcium, and vitamins to produce milk for the baby.

A balanced diet that includes all the essential nutrients in appropriate proportions is crucial for maintaining good health and preventing nutritional deficiencies.

The tube-like structure in the body that processes food.

The process of taking food into the mouth.

The breakdown of food into smaller molecules through mechanical and chemical processes.

The uptake of nutrients from digested food into the bloodstream.

The elimination of undigested food material as feces.

The process of breaking food into smaller pieces without changing its chemical composition.

The breakdown of large, insoluble food molecules into smaller, soluble molecules.

The breaking down of starch into maltose.

The breaking down of proteins into peptides and then amino acids.

The process of breaking down fats into fatty acids and glycerol.

Groups of specialized plant cells that conduct water, dissolved salts, and food.

The tissue that transports water and dissolved salts from the roots to the leaves.

The tissue that transports food substances from the leaves to other parts of the plant.

The small openings on the leaf surface that allow for gas exchange and transpiration.

The process of using absorbed nutrients to build and repair body tissues, provide energy, and carry out other cellular functions.

A severe deficiency of both calories and protein in the diet, leading to extreme thinness, muscle loss, and increased susceptibility to infections.

A form of protein-energy malnutrition (PEM) caused by a lack of protein in the diet, despite adequate calorie intake.

The process of breaking down large, insoluble food molecules into smaller, soluble molecules using enzymes that catalyze specific chemical reactions.

The tube-like structure that runs through the body, responsible for food intake, digestion, absorption, and excretion of waste.

The process of breaking down food into smaller pieces without changing the chemical composition of the food molecules. Primarily occurs in the mouth through chewing.

The process of absorbing nutrients from the digested food into the bloodstream, mainly occurring in the small intestine.

The first part of the alimentary canal where food is chewed and mixed with saliva.

A tube that transports food from the mouth to the stomach using muscular contractions.

A muscular organ where food is churned and mixed with gastric juice for chemical digestion.

A long, coiled tube where most nutrient absorption occurs, aided by villi and microvilli that increase surface area.

The final part of the alimentary canal where water and some minerals are absorbed and undigested material is eliminated.

An enzyme found in saliva that starts the breakdown of starch.

An enzyme found in gastric juice that breaks down proteins.

Tiny finger-like projections that increase the surface area of the small intestine, allowing for better absorption of nutrients.

The force exerted by blood against the walls of blood vessels.

Measured as systolic pressure (when the heart contracts) over diastolic pressure (when the heart relaxes).

A major risk factor for heart disease.

The continuous movement of blood through the body.

Blood flows from the right ventricle of the heart to the lungs for oxygenation and returns to the left atrium.

Oxygenated blood is pumped from the left ventricle to the body tissues, delivers oxygen and nutrients, and returns to the right atrium.

A muscular organ that pumps blood throughout the body.

Two atria (upper) and two ventricles (lower).

Tricuspid (right) and bicuspid (left) valves prevent backflow from ventricles to atria.

Pulmonary and aortic valves prevent backflow from arteries to ventricles.

Carry oxygenated blood away from the heart to the body tissues.

Thick, muscular walls with elastic fibers to withstand the high pressure of blood pumped from the heart.

Carry deoxygenated blood back to the heart.

Thinner walls than arteries with less muscle and more elastic tissue.

Microscopic blood vessels that form a vast network throughout the body tissues.

Carry deoxygenated blood back to the heart.

Microscopic vessels where exchange of materials between blood and tissues occurs.

The force blood exerts against the walls of blood vessels, usually measured in millimeters of mercury (mmHg).

Measured during heart contraction.

Measured during heart relaxation.

The rate at which the heart beats, usually measured in beats per minute (bpm).

Increases heart rate and breathing rate to deliver more oxygen and nutrients, especially during physical exertion.

Can cause stress hormones like adrenaline to be released, increasing heart rate.

The control center for all bodily functions.

Networks of nerves connecting the CNS to the rest of the body.

Specialized cells that transmit electrical signals (nerve impulses), allowing communication throughout the body.

Transmit signals from sensory receptors to the CNS.

Transmit signals from the CNS to effectors (muscles or glands).

Connect sensory and motor neurons, enabling communication within the CNS.

An automatic and rapid response to a stimulus, involving a sensory neuron, relay neuron, and motor neuron.

A fluid connective tissue that transports nutrients, oxygen, carbon dioxide, hormones, and waste products throughout the body.

Mammals have a double circulatory system, meaning blood passes through the heart twice during each complete circuit.

A muscular organ that pumps blood throughout the body. It has four chambers: two atria (upper chambers) and two ventricles (lower chambers).

The right side of the heart pumps deoxygenated blood to the lungs.

The left side of the heart pumps oxygenated blood to the rest of the body.

Valves within the heart ensure the unidirectional flow of blood.

Microscopic blood vessels where exchange of materials (oxygen, nutrients, waste products) occurs between the blood and body cells.

Maintains high blood pressure to ensure efficient blood flow to all organs.

Allows for efficient oxygenation of blood in the lungs.

The circulatory system in mammals is a complex and efficient system that ensures the delivery of oxygen and nutrients to all parts of the body and the removal of waste products.

The continuous upward movement of water in the xylem driven by the evaporation of water from leaves. Water molecules have strong cohesive forces, creating a continuous column that is pulled upward.

The loss of water vapor from plant leaves, primarily through tiny openings called stomata.

The tube-like cells in vascular bundles that transport water and dissolved minerals from roots to leaves.

The tube-like cells in vascular bundles that transport sugars (mainly sucrose) produced during photosynthesis from leaves to other parts of the plant.

The process by which plants absorb water from the soil through root hairs.

They increase the surface area of the root for efficient water absorption.

The movement of sucrose and amino acids in the phloem throughout the plant.

The sugar produced through photosynthesis in leaves that is transported by the phloem.

A specialized experiment used to measure the rate of water uptake by a plant, indirectly measuring transpiration.

Increased light intensity generally increases the rate of transpiration by opening the stomata on leaves, allowing more water vapor to escape.

Higher temperatures increase the rate of transpiration due to increased evaporation of water from the leaves.

High humidity decreases the rate of transpiration because the air is already saturated with water vapor, reducing the driving force for evaporation.

Wind increases the rate of transpiration by removing water vapor from the leaf surface, providing a drier environment for further evaporation.

The lower surface of a leaf typically loses more water through transpiration due to a higher density of stomata, the tiny openings that regulate gas exchange and water loss.

The junction between two neurons where nerve impulses are transmitted by chemical messengers called neurotransmitters.

The transparent front part of the eye that refracts (bends) light.

The opening in the center of the iris that allows light to enter the eye.

Contains light-sensitive cells (rods and cones) that convert light into electrical signals.

Transmits signals from the retina to the brain.

Actions that are consciously controlled by the brain.

Actions that are not consciously controlled, such as reflexes.

The ability of the eye to focus on objects at different distances. Achieved by changing the shape of the lens. For distant objects, the ciliary muscles relax, suspensory ligaments tighten, and the lens becomes thinner. For near objects, ciliary muscles contract, suspensory ligaments loosen, and the lens becomes thicker.

The iris controls the amount of light entering the eye by adjusting the size of the pupil. In bright light, circular muscles contract, constricting the pupil to reduce light. In dim light, circular muscles relax, radial muscles contract, and the pupil dilates to allow more light.

Specialized cells that transmit electrical signals (nerve impulses). Sensory neurons transmit impulses from sensory receptors to the CNS. Relay neurons connect sensory and motor neurons. Motor neurons transmit signals from the CNS to an effector (muscle or gland) to produce a response.

The junction between two neurons where nerve impulses are transmitted by chemical messengers called neurotransmitters.

A simple, automatic, and rapid response to a stimulus. It involves a sensory neuron detecting the stimulus, relay neuron connecting to the motor neuron, and the motor neuron generating a response in the effector.

Actions that are consciously controlled by the brain, like writing or speaking.

Actions that are not consciously controlled, like blinking or breathing.

A hormone released by the adrenal glands in response to stress. It prepares the body for 'fight-or-flight' by increasing heart rate, blood pressure, and breathing rate.

The part of the nervous system made up of the brain and spinal cord. It receives information from the body, processes it, and sends out responses.

The part of the nervous system made up of nerves that connect the CNS to the rest of the body. It carries information to and from the CNS.