FREE GCSE Biology Question and Answers
Which illness was erroneously associated with the MMR vaccine?
The disease that was incorrectly linked to the MMR (measles, mumps, and rubella) vaccine is autism. In the late 1990s, a now-debunked study by Dr. Andrew Wakefield suggested a potential link between the MMR vaccine and the development of autism spectrum disorders (ASD). The study, published in The Lancet, claimed to find a connection between the MMR vaccine, gastrointestinal issues, and autism.
What function do antibiotics serve?
The primary role of antibiotics is to kill or inhibit the growth of bacteria. Antibiotics are medications that are specifically designed to target and eliminate bacterial infections. They work by interfering with specific processes or structures in bacterial cells, ultimately leading to their destruction or prevention of further growth.
Where do viruses reside?
Viruses are obligate intracellular parasites, which means they rely on living host cells to reproduce and survive. Outside of a host cell, viruses are essentially inert particles and cannot carry out their life cycle or metabolic processes. They lack the necessary machinery to replicate or generate energy on their own.
What is the major justification for avoiding antibiotic overuse?
The main reason for not overusing antibiotics is the development of dangerous strains of antibiotic-resistant bacteria. Overusing antibiotics, either through unnecessary prescriptions or incorrect use, can contribute to the emergence and spread of bacteria that are resistant to the drugs that are designed to kill or inhibit them.
What does the phrase "pathogen" mean?
The term "pathogen" refers to a disease-causing organism or agent, rather than a specific disease itself. Pathogens can be microorganisms such as bacteria, viruses, fungi, or parasites, as well as certain proteins called prions. These organisms or agents have the potential to invade a host organism and cause disease by disrupting normal physiological functions.
The chemical that makes tobacco smoke addicting is
The addictive substance in tobacco smoke is nicotine. Nicotine is a natural stimulant found in tobacco leaves, and it is the primary reason why tobacco products, such as cigarettes, are highly addictive. When tobacco is smoked, nicotine is rapidly absorbed into the bloodstream through the lungs and reaches the brain within seconds.
Which of the following does not help a plant survive in dry conditions?
Large surface area is not a good adaptation for a plant in arid conditions. In arid environments, where water availability is limited, plants need to adapt in ways that reduce water loss and maximize their ability to acquire and retain water.
Which of the following does not describe a virus?
Viruses do not respire. Respiration is the process by which organisms use oxygen to produce energy through the breakdown of organic molecules. While living organisms carry out respiration to generate energy, viruses do not possess the necessary cellular machinery or metabolic pathways to respire or generate energy on their own.
The result of consuming too much saturated fat is
The effect of excess saturated fat in the diet is to increase cholesterol levels. Saturated fats are a type of dietary fat that are primarily found in animal-based foods such as meat, dairy products, and tropical oils like coconut oil and palm oil. When consumed in excess, saturated fats can lead to an increase in low-density lipoprotein (LDL) cholesterol, often referred to as "bad" cholesterol.
The metabolic rate is the speed at which chemical reactions occurs in the
Metabolic rate refers to the speed at which chemical reactions occur within cells. It is a measure of the overall energy expenditure and activity level of an organism's cells. Metabolic reactions include processes such as cellular respiration, protein synthesis, and DNA replication, among others. These reactions are essential for maintaining life, as they provide the energy and building blocks necessary for cell function, growth, and reproduction. Metabolic rate can be influenced by factors such as genetics, age, sex, body size, physical activity, and environmental conditions.
What is the most likely outcome for an individual who is not adapted to their surroundings?
The most likely outcome for an individual that is not well suited to its environment is that it will have difficulty surviving. When an organism is not well adapted to its environment, it may struggle to obtain necessary resources, withstand environmental conditions, and effectively compete with other organisms.
Who made strides in in the field of vaccinations?
Edward Jenner is widely recognized as the pioneer of modern vaccinations. He is best known for his work on smallpox vaccination. In the late 18th century, Jenner observed that milkmaids who had contracted cowpox, a relatively mild disease, seemed to be immune to smallpox, a highly contagious and deadly disease at the time. Building on this observation, Jenner hypothesized that exposure to cowpox could protect against smallpox.
Dietary protein is required because
Protein is needed in the diet for various essential functions in the body, including growth and development. While growth is one of the important roles of dietary protein, it is not the sole purpose. Proteins are complex macromolecules composed of amino acids, and they play critical roles in the body's structure, function, and overall health.
What term is given to the variable that is measured in an investigation?
In an investigation, the variable that is measured is typically referred to as the dependent variable. The dependent variable is the outcome or response that is being observed, measured, or analyzed in relation to other variables in the study. It is called "dependent" because its value is thought to depend on or be influenced by other factors, such as independent variables or experimental conditions.
A vaccine generates white blood cells to produce
A vaccine stimulates white blood cells to produce antibodies. Antibodies, also known as immunoglobulins, are proteins produced by certain white blood cells called B lymphocytes (or B cells). They are a crucial part of the immune response and play a key role in fighting off infections.
What impact does the carbon monoxide in cigar smoke have?
One of the effects of carbon monoxide (CO) in cigarette smoke is its ability to reduce the oxygen-carrying capacity of blood. When a person inhales cigarette smoke containing carbon monoxide, it is absorbed into the bloodstream through the lungs. Carbon monoxide has a higher affinity for hemoglobin in red blood cells than oxygen does, meaning it binds to hemoglobin more readily.