06 Biology and Human Body Systems Free Online FlashCards

What is the smallest unit capable of life processes?

A cell is the smallest unit capable of carrying out the processes of life.

What are two key roles of the nucleus?

The nucleus stores most of a cell’s DNA and helps direct cell activity.

How many chromosomes are in body cells and gametes?

Most human body cells have 46 chromosomes arranged in 23 pairs. Eggs and sperm have 23 chromosomes each.

How does an allele differ from a gene?

A gene is a section of DNA that provides instructions for a functional product, often a protein. An allele is a form of a gene.

What is the difference between genotype and phenotype?

Genotype is an individual’s allele combination; phenotype is an observable characteristic.

What does mitosis produce, and why is it important?

Mitosis produces two genetically similar body cells and supports growth and repair.

What does meiosis produce?

Meiosis produces gametes with one chromosome from each pair. Chromosome separation and mixing help explain how alleles pass to offspring.

What is the order of body organization from smallest to largest?

The organization proceeds from molecules to organelles, cells, tissues, organs, organ systems, and the organism.

How does an organ differ from a tissue?

A tissue is a group of cells working together; an organ contains at least two tissue types.

What are the locations and functions of epithelial tissue?

Epithelial tissue covers body surfaces, lines cavities, and forms many glands; it can protect, absorb, and secrete.

How do anatomy and physiology differ?

Anatomy describes body structures; physiology explains how those structures function.

How do negative and positive feedback differ?

Homeostasis regulates internal conditions within ranges that support normal function. Negative feedback opposes a change, while positive feedback intensifies it until an endpoint.