Living Organisms

Question 1

What are the 3 Domains of Life?

Answer 1

Bacteria, Archaea, Eukarya

Question 2

Define: Bacteria

Answer 2

Single celled prokaryotes with a simple cell structure, lacking a nucleus, and membrane-bound organelles.

They have a diverse metabolic processes and can be found in various environments

Question 3

Define Archaea

Answer 3

Single-celled prokaryotes similar to bacteria - but with distinct genetic and biochemical differences. Often found in extreme environments (e.g. hot springs, salt flats..)

Question 4

Protists

Answer 4

We use the word “protist” as an informal name to refer to eukaryotes that are not animals, plants, or fungi. Protists are extremely diverse, and can be either unicellular or multicellular, e.g. amoebas and algae

Question 5

Traits of Prokaryotic Cells

Answer 5

Lack a Nucleus: DNA is free floating in the cell

No Membrane-Bound Organelles: Simple cell structure

Smaller Size: Generally smaller than eukaryotic cells

Examples: Bacteria and Archaea

They are everywhere, first inhabitants of earth 3-3.5 billion years ago

Found in moderate and extreme climates.

Question 6

Traits of Eukaryotic Cells

Answer 6

Contain a nucleus: DNA is enclosed within a nuclear membrane

Have Membrane-Bound Organelles: Includes structures such as the mitochondria, endoplasmic reticulum, and Golgi apparatus

Larger Size: Generally larger and more complex than prokaryotic cells

Examples: plants, animals, fungi, and protists

Question 7

Roles of Biomolecules in Life: Carbohydrates

Answer 7

Provides energy and structural support.

Example: glucose (energy source) and cellulose (plant cell walls).

Question 8

Roles of Biomolecules in Life: Proteins

Answer 8

Perform a variety of functions including; enzymatic catalysis, structural support, and signaling.

Examples: enzymes, antibodies, and collagen

Question 9

Roles of Biomolecules in Life: Lipids

Answer 9

Store energy, form cell membranes, and act as signaling molecules.

Examples: fats, oils, phospholipids

Question 10

Roles of Biomolecules in Life: Nucleic Acids

Answer 10

Store and transmit genetic information. DNA carries genetic instructions, while RNA is involved in protein synthesis.

Question 11

What is a phospholipid?

Answer 11

Phospholipids are major membrane lipids that consist of lipid bilayers. This basic cellular structure acts as a barrier to protect the cell against various environmental insults and more importantly, enables multiple cellular processes to occur in subcellular compartments.

Question 12

Plasma Membrane

Answer 12

A phospholipid bilayer that surrounds and protects the cell, controlling the movement of substances in and out

Question 13

Cytoplasm

Answer 13

The jelly-like substance within the cell membrane, containing all the organelles and cell components.

Question 14

Genetic Material

Answer 14

DNA or RNA that contains the instructions for the cell’s functions and reproduction.

Question 15

Ribosomes

Answer 15

Structures responsible for protein synthesis, translating genetic info into proteins

Question 16

What are the 4 characteristics that all cells share?

Answer 16

1. Plasma Membrane
2. Cytoplasm
3. Genetic Material
4. Ribosomes

Question 17

What is a membrane-bound organelle?

Answer 17

A membrane bound organelle is an organelle that is surrounded by a phospholipid bilayer.

In simpler terms, a phospholipid bilayer is a film that consist of two layers of phospholipids, that covers and separates the organelle from the cytoplasm.

Question 18

Plant vs. Animal Cells

Answer 18

Animal cells only have an outer plasma membrane, whereas plants have a plasma membrane and a cell wall (which makes them rigid and box like)

Plants contain plastids (double-plasma membrane bound structures), such as chloroplasts and amyoplasts, but animal cells do not.

Question 19

What are the differences between a prokaryote and eukaryote?

Answer 19

Prokaryotes do not have a nucleus or other membrane bound structures (organelles), are generally smaller than eukaryotes and are mostly single celled (though some eukaryotes are single celled).