This organelle contains digestive enzymes that break down waste materials and worn-out cell parts.
lysosome
This tissue type lines body surfaces and organs and acts as a protective barrier.
epithelial tissue
This waxy layer on a leaf helps reduce water loss.
cuticle
Several organs working together form this level of organization.
an organ system
This component of blood helps form clots.
platelets
A scientist observes a cell with a nucleus but no cell wall. What type of cell is being observed?
animal cell
This tissue connects, supports, and protects structures throughout the body.
connective tissue
Most photosynthesis occurs in this layer of the leaf.
the palisade mesophyll
The digestive and circulatory systems work together to perform this function.
delivering absorbed nutrients to body cells
This blood component fights infection.
white blood cells
Why are cells generally small rather than large?
because smaller cells have a higher surface area-to-volume ratio, allowing materials to move more efficiently
This structure prevents food from entering the trachea during swallowing.
the epiglottis
These cells surround stomata and regulate their opening and closing.
guard cells
Compare the function of xylem and blood vessels.
both transport materials throughout the organism
Stem cells are especially valuable in medicine because they possess this ability.
differentiation into specialized cell types
A muscle cell requires large amounts of energy. Which organelle would likely be most abundant in the cell?
the mitochondrion
A person has damage to the villi in their small intestine. Predict the effect on digestion.
reduced nutrient absorption
A plant is losing water rapidly through transpiration. What will the guard cells most likely do?
close the stomata
A plant's roots stop absorbing water. Which tissue will be affected first?
xylem tissue
A patient loses a large number of red blood cells. Predict one consequence.
decreased oxygen transport to body tissues
A mutation causes ribosomes to stop functioning. Predict the effect on the cell.
the cell will be unable to produce proteins needed for growth and function
Explain why muscles and bones must work together to produce movement.
muscles contract and pull on bones, which act as levers
Explain how xylem tissue contributes to photosynthesis.
xylem transports water needed for photosynthesis to the leaves
Explain why multicellular organisms require specialized cells.
because no single cell can efficiently perform all life functions
A stem cell is placed in an environment that signals it to become a nerve cell. What process is occurring?
cell differentiation