Plant Cells
What three structures make plant cells unique?
Cell wall, chloroplasts, large central vacuole.
Name three different types of animal cells.
Examples: muscle cells, nerve cells, skin cells, blood cells, bone cells.
Where are organelles found?
Inside the cytoplasm (cytosol) of the cell.
Which two organelles are believed to have evolved through endosymbiosis?
Mitochondria and chloroplasts.
Compare the FUNCTION of a cell wall and a cell membrane.
Cell wall provides support; cell membrane controls movement in and out.
Why do plant cells need a cell wall if they already have a cell membrane?
The cell wall provides extra support, protection, and helps the cell keep its shape.
Why don't animal cells have chloroplasts?
Animals do not make their own food through photosynthesis.
Which organelle stores water, food, and waste?
Vacuole.
According to the Endosymbiotic Theory, what type of organisms did mitochondria and chloroplasts evolve from?
Free-living prokaryotic bacteria (mitochondria from aerobic bacteria; chloroplasts from cyanobacteria).
Which cell structure contains the fluid that surrounds all organelles?
Cytoplasm
A plant has been kept in the dark for two weeks. Which organelle can no longer perform its main job?
Chloroplast (it cannot perform photosynthesis without light).
Which organelle gives animal cells the energy needed to move and function?
Mitochondria.
Match the organelle with its function:
Name two pieces of evidence that support the Endosymbiotic Theory.
Any two: they have their own DNA, reproduce by binary fission, have double membranes, contain bacterial-like ribosomes, or are similar to bacteria in size and structure.
What would most likely happen if a cell lost its nucleus?
It could no longer control cell activities or make new proteins and would eventually die.
Explain why plant cells a large central vacuole have but animal cells usually do not. Give TWO reasons.
It stores water and helps to keep the plant upright and supported.
Compare the roles of mitochondria and chloroplasts. How are they similar and different?
Both convert energy. Chloroplasts make glucose from sunlight; mitochondria convert glucose into ATP.
Name three organelles involved in making energy or just food, and state the function of each.
Scientists discover an organelle that has its own DNA but cannot divide by binary fission. Does this provide strong evidence for endosymbiosis? Explain.
No. Endosymbiotic organelles are expected to have multiple characteristics, including their own DNA and the ability to divide by binary fission. One piece of evidence alone is not strong enough.
Why is DNA essential for a cell's survival?
DNA contains the instructions for making proteins and directing all cell activities.
Two unknown cells are viewed under a microscope. Cell A has a cell wall and a large central vacuole but no chloroplasts. Cell B has chloroplasts but no cell wall. Which cell is more likely to be a plant cell? Explain your reasoning.
Cell A. Plant cells always have a cell wall, but not all plant cells contain chloroplasts (such as root cells). A cell without a cell wall is not a typical plant cell.
A scientist compares a skin cell and a heart muscle cell. Which organelle would most likely be found in greater numbers in the heart muscle cell, and why?
Mitochondria because heart muscle cells require much more ATP to contract continuousl
A cell suddenly stops making proteins but can still make lipids. Which two organelles are most likely malfunctioning? Explain.
Ribosomes and Rough ER, because proteins are synthesized by ribosomes and transported by the Rough ER, while lipids are made by the Smooth ER.
A newly discovered organelle has its own circular DNA, divides by binary fission, has a double membrane, and contains bacterial-like ribosomes. Based on the evidence, would scientists likely conclude it evolved through endosymbiosis? Justify your answer using at least 2 pieces of evidence
Yes. The organelle has several key characteristics predicted by the Endosymbiotic Theory: its own circular DNA, binary fission, a double membrane, and bacterial-like ribosomes, strongly suggesting it evolved from an ancient bacterium.
ATP stands for:
Adenosine Tri Phosphate