Nokea
What step of the scientific method must come before generating a hypothesis?
- A. Collecting and organizing data.
- B. Communicating the results in a scientific journal.
- C. Conducting an experiment.
- D. Researching previous studies for background.
Correct Answer: D
Rationale: The correct answer is D, 'Researching previous studies for background.' Before formulating a hypothesis, it is essential to review existing literature, studies, and information related to the topic to understand the context and identify gaps in knowledge. This step helps researchers build on existing knowledge and formulate a clear hypothesis based on the information gathered. Choices A, B, and C are incorrect because they come after the step of researching previous studies and developing a hypothesis. Collecting and organizing data, conducting an experiment, and communicating results typically follow the hypothesis generation step in the scientific method.
You may also like to solve these questions
What is the main function of the pancreas?
- A. To store food and break it down into smaller pieces
- B. To absorb nutrients into the bloodstream
- C. To produce enzymes that help digest food
- D. To regulate blood sugar levels
Correct Answer: C
Rationale: The main function of the pancreas is to produce digestive enzymes that aid in breaking down carbohydrates, fats, and proteins in food. These enzymes are essential for the digestion and absorption of nutrients in the small intestine. While the pancreas also plays a role in regulating blood sugar levels by producing insulin and glucagon, its primary function is to produce enzymes for food digestion. Options A and B are incorrect as the pancreas is not involved in storing food or absorbing nutrients into the bloodstream.
What is the term for the pressure exerted by blood against the walls of blood vessels?
- A. Heart rate
- B. Blood pressure
- C. Cardiac output
- D. Stroke volume
Correct Answer: B
Rationale: Blood pressure is the term for the pressure exerted by blood against the walls of blood vessels. It is measured in millimeters of mercury (mmHg) and consists of two numbers: systolic pressure (the top number) and diastolic pressure (the bottom number). Heart rate (A) is the number of times the heart beats per minute, cardiac output (C) is the volume of blood pumped by the heart per minute, and stroke volume (D) is the volume of blood pumped by the heart in one contraction. Understanding blood pressure is crucial in assessing cardiovascular health and the risk of various conditions like hypertension.
Which structure is the largest part of the airway?
- A. Alveoli
- B. Bronchi
- C. Bronchioles
- D. Trachea
Correct Answer: D
Rationale: The correct answer is the trachea. The trachea is the largest part of the airway and serves as the main passageway for air to enter and exit the lungs. It connects the larynx to the bronchi and is an essential component of the respiratory system. The alveoli, although crucial for gas exchange, are tiny air sacs in the lungs and not the largest part of the airway. Bronchi and bronchioles are smaller airway passages that branch off from the trachea, making them smaller in size compared to the trachea.
Where is the primary site for nutrient absorption from digested food in the human digestive system?
- A. Esophagus
- B. Large intestine
- C. Small intestine
- D. Stomach
Correct Answer: C
Rationale: The small intestine is the primary site for nutrient absorption in the human digestive system. It is where the majority of digestion and absorption of nutrients from food occurs. The walls of the small intestine are lined with tiny finger-like projections called villi, which increase the surface area available for absorption. Nutrients such as carbohydrates, proteins, fats, vitamins, and minerals are absorbed through the walls of the small intestine and into the bloodstream to be transported to cells throughout the body for energy and other functions. The esophagus is a muscular tube that connects the throat to the stomach and plays a role in swallowing, not nutrient absorption. The large intestine primarily absorbs water and electrolytes from the remaining indigestible food matter after the absorption of nutrients in the small intestine. The stomach mainly functions in the mechanical and chemical breakdown of food through muscular contractions and the secretion of digestive enzymes.
Which state of matter has both a definite volume and a definite shape?
- A. Solid
- B. Liquid
- C. Gas
- D. Plasma
Correct Answer: A
Rationale: The correct answer is 'Solid.' Solids have both a definite volume and a definite shape because the particles are closely packed together and vibrate in fixed positions. This close arrangement of particles allows solids to maintain their shape and volume, unlike liquids and gases which do not have a definite shape. Liquids take the shape of their container but have a definite volume. Gases, on the other hand, do not have a definite shape or volume as they expand to fill the space available to them. Plasma is a high-energy state of matter where atoms are stripped of their electrons and is not characterized by definite shape or volume.