PHHS Biology Category 1

Front

What is the cell theory?

Back

The cell theory states that: 1) All living organisms are composed of one or more cells. 2) The cell is the basic unit of life. 3) All cells arise from pre-existing cells.

Front

Define homeostasis.

Back

Homeostasis is the process by which living organisms maintain a stable internal environment despite changes in external conditions.

Front

What is the function of the mitochondria?

Back

Mitochondria are known as the powerhouse of the cell; they produce ATP (adenosine triphosphate) through cellular respiration.

Front

Explain the role of enzymes in biological reactions.

Back

Enzymes are biological catalysts that speed up chemical reactions in cells by lowering the activation energy required for the reaction to occur.

Front

What is photosynthesis?

Back

Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose, using carbon dioxide and water.

Front

Define osmosis.

Back

Osmosis is the movement of water molecules across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Front

What is the difference between prokaryotic and eukaryotic cells?

Back

Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have a nucleus and membrane-bound organelles.

Front

What is the function of ribosomes?

Back

Ribosomes are the sites of protein synthesis in the cell, where they translate messenger RNA (mRNA) into polypeptide chains.

Front

Explain the concept of natural selection.

Back

Natural selection is the process by which organisms better adapted to their environment tend to survive and produce more offspring, leading to evolutionary changes.

Front

What is the role of DNA in cells?

Back

DNA (deoxyribonucleic acid) contains the genetic instructions for the development, functioning, growth, and reproduction of all known living organisms.