Mid Term Test

Question 1

Prokaryotic Cells

Answer 1

Single cells that lack a nucleus and membrane bound organelles, belong to Bacteria and Archaea and very small with a single circular chromosome of DNA

Question 2

Eukaryotic Cells

Answer 2

Complex cells with membrane bound organelles and a nucleus, members of Eukarya, larger in size with specialised organelles

Question 3

Cytoplasm

Answer 3

Is the liquid fluid that supports the organelles within the cell

Question 4

Cytosol

Answer 4

the liquid portion of the cytoplasm in a cell, where various cellular processes occur, and organelles are suspended. It consists mainly of water, ions, and proteins.

Question 5

Nucleus

Answer 5

The control centre of the cell, contains DNA of the cell

Question 6

Mitochondria

Answer 6

Small rod-shaped organelles where aerobic cellular respiration occurs generating ATP, also contains their own DNA

Question 7

Ribosomes

Answer 7

Tiny bodies of RNA, involved in the synthesis of proteins

Question 8

Endoplasmic Reticulum

Answer 8

System of membrane channels and is the site of processing, modification and transport of different substances

Question 9

Smooth Endoplasmic Reticulum

Answer 9

Does not have ribosomes and is the site of synthesis of lipids

Question 10

Rough Endoplasmic Reticulum

Answer 10

Covered in ribosomes and is a site of protein synthesis

Question 11

Golgi Apparatus

Answer 11

Series of flattened stacked pouches called cisternae and responsible for transporting, modifying and packaging of proteins and lipids into vesicles for delivery to the cells

Question 12

Vesicles

Answer 12

Small membrane bound sacs containing substances for the ER and the Golgi, Lysosomes are specialised vesicles containing enzymes that breakdown waste

Question 13

Chloroplasts

Answer 13

Contain a green pigment called chlorophyll, chlorophyll absorbs light energy from the sun for photosynthesis

Question 14

Vacuoles

Answer 14

Membranous sacs that act as storage sites, usually larger in plant cells and small or absent in animal cells, typically store water

Question 15

Stem Cells

Answer 15

Unspecialised cells which are capable of self-renewal and can differentiate into distinct cell types

Question 16

Embryonic Stem Cells

Answer 16

Can be collected from the blastocyst stage of an embryo

Question 17

Adult/Somatic Stem Cells

Answer 17

Present in small amounts in various adult tissues such as bone marrow, skin, intestine etc

Question 18

Potency of Stem Cells

Answer 18

The potential that a stem cell can become

Question 19

Totipotent

Answer 19

Capable of giving rise to all cell types and a complete organism e.g. Zygote

Question 20

Pluripotent

Answer 20

Capable of giving rise to all cell types but not a whole organism e.g. Embryonic Stem Cell

Question 21

Multipotent

Answer 21

Capable of giving rise to some cell type e.g. Adult Stem Cells

Question 22

Unipotent

Answer 22

Differentiate into one cell type found in a specific tissue e.g. skin epidermal into new skin cells

Question 23

Cell Cycle (4 Phases)

Answer 23

Prophase: Nuclear membrane disintegrates, chromosomes condense, spindle forms. Metaphase: Chromosomes line up and attach to spindle fibres at the centromere.Anaphase: Centromere breaks, spindle fibres pull chromosomes to poles of cell. Telophase: Nuclear membrane reforms

Question 24

Cell Differentiation

Answer 24

Differentiate into one cell type found in a specific tissue e.g. skin epidermal into new skin cells

Question 24

Mitosis (Stages)

Answer 24

G1: Cell grows and prepares for DNA synthesis S: DNA replication occurs (DNA is copied) G2: DNA prepares for division Mitosis: Cell division

Question 25

Specialised Cells

Answer 25

Specialised refers to a cell developing specific characteristics in order to perform a particular function

Question 26

Magnification

Answer 26

The number of times larger the image is than the actual specimen. Using the IAM triangle to calculate magnification

Question 27

Cell Membrane

Answer 27

Encloses the contents of the cell, it is a semi-permeable membrane that allows certain molecules to pass through

Question 28

Membrane Structure

Answer 28

A typical human cell membrane is mostly made of lipids, proteins and a small amount of carbohydrates, the fluid nature of the membrane means that components move freely in the membrane

Question 29

Fluid-Mosaic Model

Answer 29

It is described by the fluid-mosaic model, it has a lipid bilayer with associated proteins, carbohydrates and cholesterol molecules

Question 30

Phospholipids

Answer 30

Composed of a hydrophobic tail which fears water and a hydrophilic head which loves water, it is only permeable to lipid soluble molecules, all other substances must pass through carrier proteins or transport proteins

Question 31

Protein Molecules (Channels)

Answer 31

Are found in the membrane in many forms with many roles, this includes transport, support and communication

Question 32

Glycoproteins and Glycolipids

Answer 32

Are used for cell identification, attached on the surface of the cell membrane

Question 33

Passive Transport

Answer 33

Is the passive movement of molecules from a high concentration to low concentration area, occurs in liquids and gases

Question 34

Diffusion

Answer 34

Movement of molecules without requiring energy, movement requires a difference in concentration levels (from high to low concentration)

Question 34

Cholesterol

Answer 34

Cholesterol assists with the fluidity of the membrane

Question 35

Facilitated Diffusion

Answer 35

Small, charged particles and water-soluble molecules cannot pass through the membrane through simple diffusion, must travel through a transport protein, either carrier proteins for glucose or channel proteins used by ions

Question 36

Osmosis

Answer 36

Special form of diffusion referring to the movement of water molecules, follows the same principles of diffusion, movement of water from where there is lots to less

Question 37

Active Transport

Answer 37

Movement of molecules which require energy, usually against the concentration gradient or a charged ion.

Question 38

Endocytosis

Answer 38

Moves materials into the cell through the cell membrane forming vesicles

Question 39

Exocytosis

Answer 39

Moves materials out of the cell through the cell membrane forming vesicles

Question 40

Phagocytosis

Answer 40

Transport of solid particles into the cell (Endocytosis)

Question 41

Pinocytosis

Answer 41

Transports Liquids into the cell (Endocytosis)

Question 42

Surface Area to Volume Ratio

Answer 42

The size of the surface area around the membrane of a cell to the volume of cytoplasm within the cell, larger SA:V ratio means more efficient diffusion. Overcome low SA:V by changing shape (stretching out and becoming thinner)

Question 43

Factors of Rate of Diffusion

Answer 43

Concentration Gradient - The greater the gradient, faster the diffusion Temperature - Higher temp means more energy in particles, more collisions, faster diffusion Surface Area - Larger SA allows for more space for particles to cross membrane Diffusion Distance - The shorter the distance, faster diffusion can occur (height of cell)

Question 44

Organic Compounds

Answer 44

Always contain carbon, nearly all contain carbon-hydrogen bonds

Question 45

Inorganic Compounds

Answer 45

Do not contain carbon (except CO2)

Question 46

Biomolecules

Answer 46

Macromolecules which are essential for life. Four main types, Carbohydrates, Proteins, Lipids and Nucleic Acids

Question 47

Macromolecules

Answer 47

Are large molecules also called polymers, made of monomers which are basic building blocks

Question 48

Carbohydrates

Answer 48

Made of glucose monomer, main source of energy for the cell, also structural role in the cell wall of plants

Question 49

Proteins

Answer 49

Made of Amino Acids, used for structure, transport and immune

Question 50

Lipids

Answer 50

Made of fatty acid and glycerol, functions are cell membrane, long term energy storage, example is phospholipid

Question 51

Nucleic Acid

Answer 51

Monomer is nucleotides, functions contain genetic code, protein synthesis, example is DNA or RNA

Question 52

Water

Answer 52

Water is a vital molecule for life, the cell cannot function without it, helps with cell health, removing waste, distributing nutrients