Cell types and organization
This type of cell lacks a nucleus surrounded by a membrane.
What is a prokaryotic cell?
A cell needs to tightly control which ions enter and leave. Which structure provides this selective barrier?
What is the plasma membrane?
A student notices that the plants growing beside a classroom window are taller than plants growing farther from the window. She asks, “Does the amount of light a plant receives affect its growth?” What scientific step does this question represent, and what led to it?
What is a research question, generated from an observation?
Researchers vary the amount of fertilizer given to plants and measure plant height. What is the independent variable?
What is: amount of fertilizer?
This process uses light energy to make chemical energy stored in sugars.
What is photosynthesis?
In a prokaryotic cell, DNA is found in this region rather than inside a nucleus.
What is the nucleoid region?
Disrupting this network causes the cell to lose its shape and makes intracellular transport more difficult. What structure has been disrupted?
What is the cytoskeleton?
After making an observation, scientists often propose this as a possible explanation.
What is a hypothesis?
Researchers investigate whether temperature affects the speed at which an enzyme breaks down a substrate. They measure how much substrate is broken down per minute. What is the dependent variable?
substrate breakdown rate = dependent variable
A mutation prevents DNA from being transcribed into RNA. Predict what would happen to protein production and explain why.
Protein production would decrease or stop
A multicellular organism is different from a unicellular organism because it is made up of this.
What are many cells?
A protein destined to be secreted from the cell is synthesized by ribosomes attached to one organelle, transported in a vesicle, and then modified and sorted by another organelle. Name the two organelles.
What are the rough ER and Golgi apparatus?
A scientist observes that plants exposed to more light tend to grow taller. She proposes that increased light causes increased plant growth. She then states that plants given more light should have a greater average height after four weeks. The first statement is the _____, while the second is the _____.
What are a hypothesis and a prediction?
A researcher tests a drug using 50 participants. Everyone receives the drug, and blood pressure decreases.What is missing here?
What is a control group?
My flattened sacs are stacked into grana, giving me lots of membrane surface for capturing light energy.
What are thylakoids in a chloroplast?
I have a cell membrane, ribosomes, DNA, and a cell wall. I don't have a nucleus or mitochondria. What am I?
What is a prokaryotic cell?
A drug prevents microtubules from forming properly. Predict two cellular processes that could be affected.
What are cell division and intracellular transport/cell movement?
Which is more scientifically useful: “Exercise is good for people” or “Adults who exercise for 30 minutes per day will have lower resting heart rates than adults who do not”? Explain why.
What is: the second hypothesis because it makes a specific, measurable, testable prediction?
Researchers randomly assign participants to either a treatment or control group. The main purpose of random assignment is to reduce this problem by making the groups more comparable.
What is bias due to pre-existing differences between groups?
DNA → RNA → protein describes this fundamental flow of genetic information.
What is the central dogma of biology?
An organism such as Volvox consists of many cells living together, but the cells are not as dependent on specialized tissues as those of a typical animal. This type of organization is called this.
What is a colonial organism?
A cell can make proteins normally, but many of those proteins accumulate inside the cell instead of being delivered to their proper destinations. Which organelle could be malfunctioning, and why?
What is the Golgi apparatus?
A researcher finds that plants given fertilizer grow an average of 3 cm taller than plants that receive no fertilizer. Why is statistical analysis needed before concluding that the fertilizer caused the plants to grow more?
What is to determine whether the observed difference is likely to be due to the treatment rather than random variation/chance?
A researcher is testing whether fertilizer affects plant growth. All plants are given the same amount of water, light, soil, and growing space. Only the amount of fertilizer differs between groups. What principle of experimental design is being demonstrated?
What is standardization of external variables?
These folds of the inner mitochondrial membrane increase the surface area available for cellular respiration.
What are cristae?