Science Midterm

Lab Safety

Guidelines aimed at ensuring safety in laboratory settings, such as the necessity of using protective goggles. For instance, ensure safety goggles are worn when working with chemicals.

Scientific Method

A structured approach to exploring questions through observation and experimentation. For example, utilizing the scientific method to examine the effect of light on plant growth.

Steps of the Scientific Method

1. Pose a Question 2. Conduct Background Research 3. Develop a Hypothesis 4. Test the Hypothesis 5. Analyze Results and Draw Conclusions 6. Present Your Findings. Example: Proposing that plants grow taller with increased sunlight, then verifying this by contrasting plants in bright light with those in shaded areas.

Observation

Data collected through the senses during an experiment. Example: Observing that a plant’s leaves appear yellow.

Inference

A conclusion made based on observations. Example: Inferring that the plant may be lacking sufficient water due to its yellow leaves.

Metric System Prefixes

Terms that indicate measurement and magnitude, such as 'milli-' representing one thousandth. Example: A millimeter is one thousandth of a meter.

Movement (MS GREEN)

A fundamental characteristic of life that refers to the ability of organisms to move, such as plants growing towards light.

Sensitivity (MS GREEN)

The capacity of living organisms to respond to external stimuli. Example: A plant wilting in response to insufficient water.

Growth (MS GREEN)

The process of increasing size or mass in organisms. Example: A seed developing into a flowering plant.

Reproduction (MS GREEN)

The mechanism by which organisms generate offspring. Example: A flower generating seeds.

Excretion (MS GREEN)

The process of eliminating waste products from living organisms. Example: A plant shedding dead leaves.

Nutrient Exchange (MS GREEN)

The absorption and utilization of essential nutrients necessary for growth and energy. Example: Roots extracting minerals from the soil.

Gas Exchange (MS GREEN)

The interchange of gases between organisms and their surrounding environment. Example: Plants assimilating carbon dioxide and releasing oxygen during photosynthesis.

Prokaryotic Cells

Basic cell types that do not possess a nucleus or complex organelles. Example: Bacteria are categorized as prokaryotic cells.

Eukaryotic Cells

Cells that are more complex and contain a nucleus along with organelles. Example: Human cells are classified as eukaryotic.

Cell Membrane

The selectively permeable boundary of a cell that governs the movement of substances in and out. Example: The cell membrane manages glucose entry into the cell.

Nucleus

The central cellular organelle housing DNA, which governs cell functions. Example: The nucleus orchestrates the activities within the cell.

Mitochondria

Cellular components responsible for energy production. Example: Muscle cells contain numerous mitochondria to fulfill their energy requirements.

Chloroplasts

Organelles present in plant cells where photosynthesis transpires. Example: Chloroplasts utilize sunlight to generate energy in leaf cells.

Mitosis

The biological process where one cell divides to form two identical daughter cells. Example: Skin cells undergo mitosis to repair injuries.

Meiosis

A distinct type of cell division that results in four unique sex cells, each with half the normal chromosome count. Example: Meiosis is crucial in the production of sperm and eggs.

Genetics

The scientific study of heredity and how traits are transmitted from parents to offspring. Example: Investigating the inheritance patterns of traits like eye color.

Mutations

Alterations in DNA that can influence an organism's traits. Example: A mutation may result in a different colored flower.

Microscope

An instrument employed to view minute objects that cannot be seen with the naked eye. Example: Microscopes are used to examine bacteria.

Eyepiece (Ocular Lens)

The lens through which a microscope is viewed, offering typically a 10x magnification. Example: Students utilize the eyepiece to observe their slides.

Objective Lenses

Lenses on a microscope that provide different levels of magnification. Example: Switching to a 40x objective lens allows for enhanced detail.

Nosepiece

The component that holds objective lenses and allows users to switch between them. Example: Rotating the nosepiece adjusts the magnification used.

Stage

The flat area on a microscope where slides are positioned for observation. Example: A slide containing onion cells is placed on the stage for examination.

Light Source

The part of a microscope that provides illumination for viewing specimens. Example: A built-in light bulb aids in illuminating the slide for clearer visibility.

Diaphragm (Iris Diaphragm)

A mechanism that regulates the intensity of light reaching the specimen. Example: Adjusting the diaphragm enhances image clarity.

Phases of Mitosis

The distinct stages of mitosis: Prophase, Metaphase, Anaphase, and Telophase. Example: In Metaphase, chromosomes align at the equatorial plane of the cell.

Purpose of Mitosis

Mitosis generates new cells necessary for growth and tissue repair. Example: The body utilizes mitosis to replenish dead skin cells.