Cell Biology Concepts

Front

The nucleus is the smallest unit in which life processes can be carried out.

Back

False. The cell is the smallest unit in which life processes can be carried out.

Front

Robert Hooke pioneered the study of cells when he developed the cell theory.

Back

False. Robert Hooke discovered cells, but the cell theory was developed later by others.

Front

Osmosis causes cells to expand when they are put in saltwater.

Back

False. Osmosis causes cells to shrink in saltwater due to water moving out of the cell.

Front

Cells without a nucleus reproduce by using binary fission.

Back

True. Prokaryotic cells, which lack a nucleus, reproduce by binary fission.

Front

A large single-celled organism would not be able to sustain itself.

Back

A unicellular organism can never grow large because it relies on diffusion for nutrient uptake and waste removal, which becomes inefficient as size increases.

Front

Mitosis forms identical daughter cells, while meiosis forms sex cells.

Back

Mitosis and meiosis differ in their outcomes; mitosis produces identical cells, while meiosis produces genetically diverse sex cells.

Front

Four different nitrogen bases are used in the structure of DNA: adenine, cytosine, guanine, and thymine.

Back

The structure of DNA consists of four nitrogen bases: adenine (A), cytosine (C), guanine (G), and thymine (T).

Front

Each DNA nucleotide is composed of a nitrogen base, a sugar, and a phosphate molecule.

Back

A DNA nucleotide is made up of a nitrogen base, a deoxyribose sugar, and a phosphate group.

Front

Both diffusion and osmosis let a cell move materials around without using any energy.

Back

A common feature of diffusion and osmosis is that they both occur without energy expenditure.

Front

The bonds between DNA bases become “rungs” of a ladder—T and A match up, and C and G match up.

Back

DNA bases pair up as follows: adenine pairs with thymine (A-T) and cytosine pairs with guanine (C-G).