Biology Review Flashcards
What are the characteristics of living things?
Movement, respiration, sensitivity, growth, reproduction, excretion, and nutrition.
What are cells?
Cells are the smallest unit that can perform the functions of life.
How many cells are our bodies made up of?
10 trillion and 100 trillion cells.
What is the Cell Theory timeline?
Hooke 1665: Observed remains of dead plant cells.
Leeuwenhoek 1673: First to see a living cell using a simple microscope.
Schleiden 1838: All plants are made up of cells.
Schwann 1839: All animals are made of cells.
Virchow 1855: Reasoned that cells come from other cells.
How else do cells divide?
- Reproduction: Single-celled organisms, like yeast and bacteria, reproduce through cell division, creating daughter cells that are exact genetic copies of themselves.
- Growth: By the time you were born, most of your body’s cells had already developed into specialized types. These cells divide and expand as you grow. Every person, including you, began as a single cell (zygote) and developed through cell division and specialization.
- Repair: Cell division helps repair injuries, like a cut, and fights infections. For example, bone marrow produces immune cells to combat infections and generate new cells for healing broken bones.
What is the Cell Theory?
- All living things are made up of one or more cells.
- The cell is the simplest unit that can carry out all life functions.
- All cells come from pre-existing cells.
What are prokaryotes?
Simple, single celled organisms. Their cells do not contain a nucleus or other membrane bound organelles, like bacteria.
What are eukaryotes?
Complex single-celled or multicellular organisms. Their cells contain a nucleus and other organelles, each surrounded by a thin membrane, like plants, animals, fungi, and protists.
What are some common misconceptions about cells?
- All animal cells are circular and all plant cells are rectangular.
- Cells differ widely in terms of shape. - All animal and/or plant cells are identical in terms of structure. For example, all cells contain a nucleus.
- Red blood cells are enc
What are organelles?
Cell structures that perform a specific function for the cell. They can be membrane-bound (surrounded by a membrane) or not.
What special functions do the cell’s organelles have in maintaining all the life processes of the cell?
Intake of nutrients, response to stimuli, movement, growth, exchange of gases, reproduction, and waste removal.
What are the parts of an animal cell?
Nucleus, nucleolus, cell membrane, cytoplasm, mitochondria, ribosomes, lysosomes, vesicles, endoplasmic reticulum, chromatin, and cytoskeleton.
What is the cell membrane (gatekeeper) and what is its function?
The cell membrane is the outer covering of the cell that forms a protective barrier around it. The cell membrane is designed to allow different substances to move through it.
What are ribosomes (assembly line workers) and what are their functions?
Ribosomes are small spherical sturctures that can be free-floating in the cytoplasm or attached to ER. Their function is to make proteins.
What are the two types of ER?
Smooth and rough (with ribosomes attached).
What is the mitochondria (powerhouse of the cell) and what is its function?
Mitochondria is a bean-shaped organelle that contains many cells. It makes energy for the cell’s activities.
What is the nucleus (brain) and what is its function?
The nucleus is the control center organelle of the cell as it controls all the activities in a cell, including growth and reproduction. The nucleus contains all of the cell’s DNA.
What is the nucleolus (factory) and what is its function?
The nucleolus (also known as “little nucleus”) is the dense structure in the nucleus. Its function is to make ribosomes.
What are golgi bodies (Fed Ex) and what are its functions?
Golgi bodies receive proteins from the endoplasmic reticulum. Their function is to modify, sort, and package proteins, lipids, and carbohydrates, into small vesicles for delivery to targeted destinations.
What are vesicles (mail) and what is their function?
Vesicles are single layer membranes that enclose fluids in a sac. Their purpose is to store and/or transport materials.
What is the cytoplasm (river/ground) and what are its functions?
The cytoplasm is a jelly-like substance that fills the cell and surrounds the organelles. Cytoplasm contains the nutrients required by the cell to carry on its life processes. The physical nature of the cytoplasm allows the nutrients and organelles to move within the cell.
What are lysosomes (Lysol/cleaner) and what is its function?
Lysosomes are small organelles that are filled with enzymes, where digestion takes place. They also break down invading bacteria and damaged cell organelles.
What is the endoplasmic reticulum, aka ER (conveyor belt) and what are its functions?
The endoplasmic reticulum are tubes that branch into cytoplasm and are near/around the nucleus. It transports materials throughout the cell as ribosomes are attached to the outside.
What is the chromosome/chromatin (blueprint) and what is its function?
The chromosome/chromatin contains DNA that is “loose”/unwound as it is in the nucleus.