ACC Biology - Chapter 1: Characteristics of Life, Homeostasis, Metabolism & Organization

Flashcards covering key concepts from ACC Biology Chapter 1, including characteristics of life, homeostasis, metabolism, energy flow, taxonomic classification, and biological organization.

What are the 8 characteristics of life?

Made of cells; reproduce; have DNA; grow and develop; obtain and use energy; respond to stimuli/environment; maintain homeostasis; adapt/evolve.

What does it mean that living things are made of cells?

All living things consist of one or more cells.

What is asexual reproduction?

Reproduction involving one parent that usually produces genetically similar offspring.

What is sexual reproduction?

Reproduction in which genetic material comes from two parents, producing greater genetic variation.

What is mitosis?

Cell division used for growth and repair that produces two genetically similar cells.

What is meiosis?

Cell division that produces sex cells (gametes) and creates genetic variation.

What is DNA?

Genetic material containing instructions that influence an organism's structure, function, development, and inherited characteristics.

Why do living things need energy?

To grow, move, repair cells, reproduce, and maintain homeostasis.

What is metabolism?

The sum of all chemical reactions occurring in an organism.

What is anabolism?

The building of larger molecules from smaller molecules; example: building proteins from amino acids.

What is catabolism?

The breaking down of larger molecules into smaller molecules, often releasing energy.

What is homeostasis?

Maintaining a relatively stable internal environment.

What is negative feedback?

A response that reverses a change and brings a condition back toward its normal range.

What part of the brain helps regulate body temperature?

The hypothalamus, which acts like a thermostat.

What is normal human body temperature?

About $37\,^\circ\text{C}$ or $98.6\,^\circ\text{F}$.

What happens when the body is too hot?

Sweating and vasodilation help release heat and cool the body.

What is vasodilation?

Widening of blood vessels near the skin, increasing blood flow and heat loss.

What happens when the body is too cold?

Shivering, vasoconstriction, and increased heat production help conserve or generate heat.

What is vasoconstriction?

Narrowing of blood vessels near the skin, reducing blood flow and heat loss.

How does shivering help the body?

Rapid muscle contractions produce heat.

What is a hormone?

A chemical messenger released by a gland that travels through the bloodstream and affects target cells or organs.

What does insulin do?

When blood glucose is too high, insulin helps cells take in glucose and promotes storage of glucose, lowering blood glucose.

What does glucagon do?

When blood glucose is too low, glucagon signals the liver to release glucose, raising blood glucose.

Where are insulin and glucagon produced?

In the pancreas.

What is BMR?

Basal metabolic rate: the amount of energy the body uses at rest to maintain basic life functions.

What factors can influence BMR?

Age, body size/height, sex, muscle mass, genetics, and hormones.

What does the thyroid gland do?

It produces hormones that help regulate metabolism.

Why is iodine important?

The body needs iodine to make thyroid hormones.

What is an adaptation?

An inherited characteristic that helps an organism survive and reproduce in its environment.

How do adaptations become common?

Through natural selection over many generations, as helpful inherited traits become more common in a population.

What are the levels of biological organization from smallest to largest?

Atom → molecule → organelle → cell → tissue → organ → organ system → organism → population → community → ecosystem → biosphere.

What is an emergent property?

A characteristic that results when individual parts interact and work together; the property is not present in the parts alone.

Are viruses generally considered living?

No. They are generally not considered living because they are not made of cells and cannot independently reproduce or carry out metabolism.

Why can viruses reproduce but still not be considered living?

They can reproduce only by using a host cell's machinery rather than reproducing independently.

How do plants obtain energy?

They use photosynthesis to convert light energy into chemical energy.

How do animals obtain energy?

They obtain energy by consuming food and release usable energy through cellular respiration.

Is energy recycled in an ecosystem?

No. Energy flows through ecosystems and is eventually lost as heat.

Is matter recycled in ecosystems?

Yes. Matter can be recycled through ecosystems.

Who is known as the father of classification?

Carl Linnaeus.

What is binomial nomenclature?

The scientific naming system that gives each organism a two-part name: genus and species.

What are the levels of taxonomic classification?

Kingdom → Phylum → Class → Order → Family → Genus → Species.

What are the two parts of a scientific name?

Genus and species.

What is an example of binomial nomenclature?

Homo sapiens: Homo is the genus and sapiens is the species.

What is the difference between anabolism and catabolism?

Anabolism builds larger molecules; catabolism breaks larger molecules down.

What is the difference between insulin and glucagon?

Insulin lowers blood glucose; glucagon raises blood glucose.

What is the difference between vasodilation and vasoconstriction?

Vasodilation widens skin blood vessels to increase heat loss; vasoconstriction narrows them to reduce heat loss.

What is the difference between mitosis and meiosis?

Mitosis produces two genetically similar body cells for growth/repair; meiosis produces genetically different sex cells.

What are the two main types of feedback mentioned in this unit?

Positive feedback and negative feedback; negative feedback counteracts a change to maintain stability.