LIFE SCI Flashcards
What is the basic unit of life?
Cell
Cells are the foundational building blocks of all living organisms.
Define tissues in biological organization.
Groups of cells with similar structure and function.
What are organs?
Structures made up of tissues working together to perform specific functions.
What defines organ systems?
Groups of organs working together to carry out a function.
What is the composition of organisms?
Made up of one or more organ systems.
What are the three main tenets of modern cell theory?
- The cell is the smallest living unit in all organisms.
- All living things are composed of cells.
- All cells come from pre-existing cells.
What are prokaryotes?
Found in bacteria and archaea; no nucleus and no membrane-bound organelles.
What defines eukaryotes?
Found in fungi, protists, animals, and plants; have a nucleus and membrane-bound organelles.
What is the function of the cell membrane?
Separates the interior of the cell from the external environment and exhibits selective permeability.
What is cytoplasm?
A fluid that fills the cell.
What is the role of ribosomes?
The site of protein synthesis in the cell.
What is the nucleus?
The control center of eukaryotic cells; contains DNA.
What is the function of the endoplasmic reticulum (ER)?
processing molecules and folding proteins.
- Rough ER:
o Covered in ribosomes.
o In protein synthesis and transport. - Smooth ER:
o Produces lipids and hormones.
o Detoxifies chemicals and stores calcium.
What are the two types of endoplasmic reticulum?
- Rough ER: Covered in ribosomes and facilitates protein synthesis and transport.
- Smooth ER: Produces lipids and hormones, detoxifies chemicals and stores calcium.
What is the function of the Golgi apparatus?
Packages and processes proteins and lipids for export.
What is the primary function of mitochondria?
Generates most of the cell’s energy through biochemical reactions and produces ATP.
What is the role of chloroplasts in plant cells?
The site of photosynthesis; converts sunlight into chemical energy.
What do lysosomes contain?
Digestive enzymes to break down waste and worn-out cell parts.
What are vacuoles and their functions in animals and plants?
- In animals: Sequester waste products.
- In plants: Maintain water balance.
What is mitosis?
A type of cell division that produces two identical daughter cells.
What is meiosis?
A type of cell division that produces four daughter cells with half the chromosomes of the parent cell.
Define heredity.
The passing of physical or mental characteristics from one generation to the next.
What is DNA?
The self-replicating material present in all living organisms; the main constituent of chromosomes.
What is the structure of DNA?
Composed of phosphate, deoxyribose (sugar), and nitrogenous bases forming a nucleotide.