Question

Match each description with the correct characteristic of life from the key. a. Life is organized. b. Living things reproduce and grow. c. Living things respond to stimuli. d. Living things have an evolutionary history. e. Living things acquire materials and energy. Human heart rate increases when scared.

Short answer

Human heart rate increases when scared - c. Living things respond to stimuli.

Step-by-step solution

Understanding the descriptions

Before matching the descriptions to the correct characteristics of life, let's understand what each description means: a. Life is organized: This refers to the structured and organized nature of living organisms. b. Living things reproduce and grow: This means that living organisms have the ability to reproduce and grow over time. c. Living things respond to stimuli: This characteristic refers to the ability of living organisms to react to changes in their environment. d. Living things have an evolutionary history: This characteristic highlights the fact that living organisms have evolved and adapted through generations. e. Living things acquire materials and energy: This characteristic focuses on the fact that living organisms require materials and energy to maintain life processes.

Identify the best match for human heart rate increasing when scared

Now that we have analyzed each description, we need to identify which description best fits the human heart rate increasing when scared. Human heart rate increasing when scared demonstrates a reaction to a change or stimulus in the environment. This matches the characteristic "Living things respond to stimuli". Therefore,

Answer

Human heart rate increases when scared - c. Living things respond to stimuli.

Key concepts

Life Organization

Life organization refers to the structured way living organisms are built and maintained. All life forms — starting from single cells to complex multicellular organisms like humans — are highly organized.

• Organelles, such as the nucleus and mitochondria, function within cells to perform specific tasks.
• Cells come together to make tissues, which make organs.
• Organs work together to form organ systems, allowing an organism to survive and thrive.

This organization allows organisms to efficiently carry out life processes, ensuring that life is maintained and passed on. It's the unique organization that distinguishes living beings from non-living matter.

Response to Stimuli

The ability to respond to stimuli is crucial for survival. It involves sensing changes in the environment and reacting appropriately. For example, when humans perceive a threat, their bodies respond by increasing their heart rate — a classic fight-or-flight response.

• In plants, stimuli may include changes in light or gravity, prompting growth in a certain direction.
• Animals often react to potential danger by fleeing or attacking.

This capability helps organisms to adapt to changes and ensures they can interact effectively with their surroundings.

Evolutionary History

Evolutionary history refers to the changes that organisms go through across generations. This characteristic captures how species adapt to their environments over time.
Life on Earth has a rich evolutionary past that documents changes such as the development of new species and the adaptation of existing ones.

• Fossils show how life evolved over millions of years.
• Genetic studies reveal common ancestors and evolutionary paths.

Understanding evolutionary history helps scientists comprehend how life forms have adapted and diversified on our planet.

Material and Energy Acquisition

All living organisms need materials and energy to function. This acquisition is fundamental for sustaining life.
Plants, through photosynthesis, convert sunlight into energy, whereas animals consume plants, other animals, or both to get their energy.

• Photosynthesis provides the primary energy source for plants.
• Animals break down food to obtain the necessary energy and nutrients.

This exchange of energy and materials is essential for processes such as growth, reproduction, and maintaining homeostasis.

Reproduction and Growth

Reproduction and growth are fundamental characteristics of life. They ensure the continuation of a species.

• Reproduction can be sexual, involving two parent organisms, or asexual, involving just one.
• Through growth, cells increase in size and number, allowing organisms to develop from a single cell to a complex being.

These processes enable life to persist across generations, passing on genetic material and fostering biodiversity. Both reproduction and growth are driven by the intricate processes encoded in an organism's DNA.