Cell Biology (SL)

Question 1

What is cell theory?

Answer 1

Theory that states that all organisms are composed of cells, and that all cells come from pre-existing cells.

Question 2

What is homeostasis?

Answer 2

The process in which an organism regulates activities within cells and their bodies to keep conditions stable.

Question 3

What is magnification?

Answer 3

Ratio of image size to actual size.

Question 4

What is metabolism?

Answer 4

The sum of all of the chemical reactions that occur within an organism or within a cell.

Question 5

What is cytoplasm?

Answer 5

Contents of a cell enclosed by the plasma membrane, not including the nucleus.

Question 6

What is cytoskeleton?

Answer 6

A network of interlinking protein filaments and tubules present in the cytoplasm of cells.

Question 7

What is differentiation?

Answer 7

The alteration of a cell’s morphology and physiology through changes in gene expression.

Question 8

What is DNA?

Answer 8

A form of nucleic acid.

Question 9

What is an electron microscope?

Answer 9

Microscope in which beams of electrons replace light so the magnification and resolution are much greater.

Question 10

What is endoplasmic reticulum?

Answer 10

A system of membranes in the cytoplasm of eukaryotic cells formed of flattened sacs, existing as rough ER (with ribosomes) or smooth ER (without ribosomes).

Question 11

What is a eukaryote?

Answer 11

Cells with membrane-bound nuclei and organelles.

Question 12

What is fertilization?

Answer 12

The fusion of male and female gametes to form a zygote.

Question 13

What is freeze-fracture?

Answer 13

A technique that involves breaking apart a frozen biological sample to expose structural details for examination in an electron microscope.

Question 14

What is gene expression?

Answer 14

The synthesis of a functional gene product, often protein, but also rRNA, tRNA, or snRNA.

Question 15

What is the Golgi apparatus?

Answer 15

A stack of flattened membranes, involved in processing, modifying and packaging of molecules.

Question 16

What are microvilli?

Answer 16

Tiny infoldings of the plasma membrane, making a ‘brush border’.

Question 17

What are mitochondria?

Answer 17

Organelle in eukaryotic cells, site of Krebs cycle and electron transport pathway.

Question 18

What is a nucleoid?

Answer 18

A region of the prokaryotic cell where DNA is located.

Question 19

What is an organelle?

Answer 19

A sub-cellular structure or membrane-bound compartment with a distinct structure and function.

Question 20

What is the plasma membrane?

Answer 20

Membrane made of lipid and protein that forms the surface of cells.

Question 21

What is a prokaryote?

Answer 21

Type of cell without a membrane-bound nucleus.

Question 22

What is a stem cell?

Answer 22

A relatively undifferentiated cell that can give rise to other types of cells and retains the ability to divide.

Question 23

What is a stem cell niche?

Answer 23

Specific microenvironment in the body that either maintain stem cells or promote their proliferation and differentiation.

Question 24

What is the surface area to volume ratio?

Answer 24

A variable that decreases as cells grow, so that it sets a limit to the size of cells.

Question 25

What is a vacuole?

Answer 25

A fluid filled space in the cytoplasm, can be large and permanent in plant cells.

Question 26

What is a vesicle?

Answer 26

Membrane-bound sac.

Question 27

What is a histone?

Answer 27

A protein associated with DNA that plays a role in gene expression and the packing of DNA.

Question 28

What is naked DNA?

Answer 28

DNA not associated with histones.

Question 29

What is a nucleus?

Answer 29

Membrane-bound organelle found in eukaryotes; contains DNA and is the site of DNA replication and transcription.

Question 30

What is an eyepiece graticule?

Answer 30

A graduated scale that is placed inside the eyepiece of the microscope, used as a ruler to measure lengths of structures.

Question 31

What is immunofluorescence microscopy?

Answer 31

Uses antibodies fluorescently tagged to bind specifically to a corresponding antigen as a probe for identifying a particular molecule in cells, tissues, or biological fluids.

Question 32

What are centrioles?

Answer 32

A minute cylindrical organelle near the nucleus in animal cells, occurring in pairs and involved in the development of spindle fibers in cell division.

Question 33

What are aseptate fungi?

Answer 33

Type of fungi with hyphae that is not partitioned by septa; multinucleated.

Question 34

What are skeletal muscle fibres?

Answer 34

Large nucleated structure, formed from many cells that fuse together to form a long fibre.

Question 35

What are phloem sieve tube elements?

Answer 35

Made up of many cells joined end to end to form a long, hollow structure, used to transport sap.

Question 36

What is the structure of a red blood cell?

Answer 36

Small flexible cell with no nuclei and few organelles, shape is biconcave.

Question 37

What are multipotent stem cells?

Answer 37

Stem cells that can become a limited number of types of tissues and cells in the body.

Question 38

What are pluripotent stem cells?

Answer 38

Stem cells that can become almost all types of tissues and cells in the body.

Question 39

What are totipotent stem cells?

Answer 39

Stem cells that can differentiate into any type of specialized cells found in organisms of that species.

Question 40

What is a morphogen?

Answer 40

A signaling molecule that flows between nearby cells and alters gene expression, causing cell differentiation in early-stage embryo.