Levels of Organization
What is the basic unit of structure and function in all living organisms?
Cell
What molecule contains the instructions for making proteins?
DNA
Which organelle produces energy (ATP) for the cell?
Mitochindria
What is the process by which stem cells become specialized cells?
Differentation
Which type of tissue conducts electrical impulses?
Nervous Tissue
A group of similar cells working together forms what level of organization?
Tissue
What is a segment of DNA that codes for a specific protein called?
Gene
Which structure makes proteins for the cell?
Ribosome
What type of specific stem cell can become nearly any type of cell in the body?
Embryonic Stem Cell
Which neuron carries signals from receptors in the skin to the brain?
Sensory Neuron
Put these in order from simplest to most complex: tissue, organ, cell, system
Cell → tissue → organ → system
Why do muscle cells and nerve cells have different functions even though they have the same DNA?
They express different genes.
Which organelle contains DNA and controls gene expression?
Nucleus
How do adult stem cells differ from embryonic stem cells?
Adult stem cells are more limited in the types of cells they can become.
Which neuron carries signals from the brain to muscles?
Motor Neuron
Which level of organization is common to both unicellular and multicellular organisms?
Cell
True or False: During differentiation, cells lose the DNA they do not need.
False (genes are turned on or off, DNA is not lost)
Why do muscle cells contain more mitochondria than cheek cells?
Muscle cells need more energy for contraction.
Why are stem cells important for healing and repair?
They can divide and become specialized cells to replace damaged tissue.
Which part of a neuron receives signals from other neurons?
Dendrites
Explain why an organ is more complex than a tissue.
An organ is made of multiple tissues working together to perform a specific function.
Explain how gene expression determines which proteins are produced in a cell.
Only certain genes are activated, so only specific proteins are made, determining the cell’s function.
Which type of cell has a cell wall and chloroplasts?
Plant Cell
Explain how gene activation is involved in stem cell differentiation.
Signals turn specific genes on or off, causing the stem cell to become a specialized cell.
Explain how learning is related to synapse strengthening in the brain.
Repeated activity strengthens synapses, making signals more efficient and forming memories.