B2.1 HL only

Question 1

Membrane fluidity

Answer 1

the property of the cell membrane that allows it to adapt its shape and movement to different conditions

Question 2

cytokinesis

Answer 2

the physical process of cell division, which divides the cytoplasm of a parental cell into two daughter cells

Question 3

viscosity

Answer 3

a measure of a fluid’s resistance to flow

Question 4

Hydrocarbon

Answer 4

an organic compound made of nothing more than carbons and hydrogens

Question 5

Saturated

Answer 5

if there are only single bonds between neighboring carbons in the hydrocarbon chain

Question 6

double bond

Answer 6

A double bond occurs when two atoms share two sets of electrons

Question 7

Unsaturated

Answer 7

a fat or fatty acid in which there is at least one double bond within the fatty acid chain

Question 8

intermolecular forces

Answer 8

the attractive and repulsive forces that arise between the molecules of a substance

Question 9

Notothenioid fish

Answer 9

Thenotothenioid fishesof the Southern Ocean surrounding Antarctica are remarkable examples of organismal adaptation to extreme cold

Question 10

Caribou

Answer 10

Large hoofed animals belonging to the deer family, caribou and reindeer are actually the same species

Question 11

Cholesterol

Answer 11

a structural component of cell membranesand serves as a building block for synthesizing various steroid hormones, vitamin D

Question 12

Bulk transport

Answer 12

a mode of transport of large quantities of materials and food particles across the membrane

Question 13

Endocytosis

Answer 13

the process by which cells take in substances from outside of the cell by engulfing them in a vesicle

Question 14

Exocytosis

Answer 14

a process for moving large molecules out of the cell to the cell exterior

Question 15

Pinocytosis

Answer 15

a process by which the cell takes in the fluids along with dissolved small molecules

Question 16

central vacuole

Answer 16

large, membrane-bound organelles found in plant cells that act as a storage space for water and other molecules in the cell

Question 17

phagocytosis

Answer 17

The process by which a phagocyte (a type of white blood cell) surrounds and destroys foreign substances (such as bacteria) and removes dead cells

Question 18

Receptor-mediated endocytosis

Answer 18

a form of endocytosis in which receptor proteins on the cell surface are used to capture a specific target molecule

Question 19

Neurotransmitters

Answer 19

are endogenous chemicals that allow neurons to communicate with each otherthroughout the body

Question 20

synapse

Answer 20

the site of transmission of electric nerve impulses between two nerve cells (neurons) or between a neuron and a gland or muscle cell (effector)

Question 21

Hormones

Answer 21

chemical substances that act like messenger molecules in the body

Question 22

homeostasis

Answer 22

any self-regulating process by which biological systems tend to maintain stabilitywhile adjusting to conditions that are optimal for survival

Question 23

Neurotransmitter-gated / Ligand-gated

Answer 23

membrane proteins that mediate information transfer at synapses. Their function relies on the ability to respond very rapidly to the transient release of a neurotransmitter to produce a change in membrane potential of the postsynaptic cell

Question 24

Na+ voltage-gated channels

Answer 24

Voltage-gatedsodium channelsare transmembrane proteins that open when the membrane potential in their vicinity become depolarized

Question 25

resting potential

Answer 25

the electrical potential difference across the plasma membrane when the cell is in a non-excited state

Question 26

depolarization

Answer 26

a process that shifts the electrical charge distribution so that the cell is less negatively charged compared to the environment

Question 27

K+ voltage-gated channels

Answer 27

transmembrane channels specific for potassium and sensitive to voltage changes in the cell’s membrane potential. During action potentials, they play a crucial role in returning the depolarized cell to a resting state

Question 28

repolarization

Answer 28

a stage of an action potential in which the cell experiences a decrease of voltage due to the efflux of potassium (K+) ions along its electrochemical gradient

Question 29

Nicotinic acetylcholine receptor

Answer 29

receptor polypeptides that respond to the neurotransmitter acetylcholine. Nicotinic receptors also respond to drugs such as the agonist nicotine

Question 30

acetylcholine

Answer 30

a neurotransmitter, a chemical that carries messages from your brain to your body through nerve cells

Question 31

neuromuscular junction

Answer 31

a synaptic connection between the terminal end of a motor nerve and a muscle

Question 32

muscle contraction

Answer 32

an increase in the tension or a decrease in the length of a muscle

Question 33

nicotine

Answer 33

a natural ingredient acting as a botanical insecticide in tobacco leaves

Question 34

ATP molecule

Answer 34

the source of energy for use and storage at the cellular level

Question 35

hydrolyzed

Answer 35

any chemical reaction in which a molecule of water breaks one or more chemical bonds

Question 36

phosphorylation

Answer 36

the addition of a phosphoryl (PO3) group to a molecule. In biological systems, this reaction is vital for the cellular storage and transfer of free energy using energy carrier molecules

Question 37

conformational change

Answer 37

a change in the shape of a macromolecule, often induced by environmental factors

Question 38

co-transporter

Answer 38

subcategory of membrane transport proteins (transporters) that couple the favorable movement of one molecule with its concentration gradient and unfavorable movement of another molecule against its concentration gradient

Question 39

Sodium-glucose linked transporter (SGLT)

Answer 39

large family of membrane proteins that transport glucose, amino acids, vitamins, osmolytes, and several ion species across the brush-border membrane of the intestinal epithelium andproximal renal tubulesthrough the use of the electro-chemical sodium gradient as the source of energy

Question 40

tubules

Answer 40

small tube or similar type of structure

Question 41

nephron

Answer 41

the basic structural and functional unit of the kidney

Question 42

filtrate

Answer 42

solution of nutrients and waste material removes from the blood in the kidneys

Question 43

emergent properties

Answer 43

characteristic an entity gains when it becomes part of a bigger system

Question 44

Cell-adhesion molecules (CAM)

Answer 44

a subset of cell surface proteins that are involved in the binding of cells with other cells or with the extracellular matrix (ECM), in a process called cell adhesion

Question 45

Desmosomes

Answer 45

a specialized structure of the cell membrane especially of an epithelial cell that serves as a zone of adhesion to anchor contiguous cells together

Question 46

Tight junctions

Answer 46

a type of cellular junction formed between adjacent epithelial cells or between adjacent epithelial cells

Question 47

Plasmodesmata

Answer 47

small channels that directly connect the cytoplasm of neighboring plant cells to each other, establishing living bridges between cells

Question 48

Cancer

Answer 48

a disease caused when cells divide uncontrollably and spread into surrounding tissues

Question 49

mutations

Answer 49

Any change in the DNA sequence of a cell

Question 50

metastasis

Answer 50

The spread of cancer cells from the place where they first formed to another part of the body