Unit Test Answers

This table shows how the levels of classification have changed with each major scientist.

When scientists first started mapping human genes, they estimated that there were about 2 million genes. By the late 1990s, it was thought that there were only 100,000 genes, and then that number shrank to 19,000 in 2001. Most scientists now believe that humans have about 21,000 genes.Which statement describes these estimates?

Cell membranes are primarily made of a component that contains fatty acids. This component is most likely a...

In these chemical compounds, C is for carbon, O is for oxygen, N is for nitrogen, and H is for hydrogen.Which chemical compound is most likely inorganic?

The idea that people behave in odd ways on a full moon is an example of

Students are experimenting with a substance that they think can be added to soil to increase the number of flowers a certain plant will make. They set up 20 pots of soil, each planted with the same type of seed. They divide the pots into two groups and add 15 drops of the substance to pots in one group and only 10 drops to pots in the other group. After the plants grow for four weeks, the students count how many flowers each plant has made.

Which are scientific questions that can be asked about a collection of different orchid types? Check all that apply.

accuracyprecisionreplicationrepetition

Isaac is studying relationships between organisms in the phylum Chordata, which includes humans and all other animals with a backbone.

Which statements are true of all scientific endeavors?

Who would have first made this statement while observing cork under a microscope?"The cork looks like little rooms, or cells.”

Which organelle can make food using sunlight?

Rahma took these notes on a process involving the movement of molecules, but she forgot to title them.–Causes molecules to move until they are evenly distributed–Moves from high concentration to low concentration–Has no need for added energy–Can occur with or without a membrane being presentWhich title best fits Rahma’s notes?

The picture shows molecules inside and outside of a cell. Assume that the molecules can pass through the cell membrane.

Which is a component of cell theory?

Which controls the movement of waste out of the cell?

Which best describes what happens when a cell shrinks and shrivels due to osmosis?

There are 25 elements found in living things. How many of these elements are found in some organisms but not all?

Which statement describes the energy involved in diffusion?

This Venn diagram is being used to compare the classification systems of Aristotle and Whittaker.

What should scientists do after completing a scientific investigation?

This chart shows four atoms, labeled W, X, Y, and Z. These atoms can combine with each other to form molecules.

Mildew is a fungus that grows in wet areas and can slowly grow from microscopic to large stains in showers and sinks. Researchers are studying different sprays that could be used to slow down the growth of mildew. They set up different showers that are exactly the same and expose them each to water with the same microscopic amount of mildew. They then spray some showers with mildew-preventing sprays and observe how fast mildew grows over time.

Examine the diagram of a cell.

Examine the diagram of a cell.