Topic 1 Cells

Question 1

Define ‘Nutrition”

Answer 1

The intake and use of food and nutrients by organisms.

Question 2

Define “metabolism”

Answer 2

The conversion of organic molecules in an organism

Question 3

Define “Growth”

Answer 3

The increase of size* within an organism.

*size/mass/number of cells

Question 4

Define “Response”

Answer 4

Response/Sensitivity/Irritability

A reaction an organism has due to a stimuli

Question 5

Define “Homeostasis”

Answer 5

The regulations of the interior environment of an organism

Question 6

Define “Reproduction”

Answer 6

Production of offspring

Question 7

Define “Excretion”

Answer 7

The process by which an organism gets rid of metabolic wastes

Question 8

Define “Cytoplasm”

Answer 8

The cytoplasm is a jelly-like substance between the nucleus and the cell membrane. Various cell organelles like ribosomes, mitochondria, endoplasmic reticulum, etc. are suspended in the cytoplasm. It helps in the exchange and storage of substances among cell organelles.

Question 9

Define “Zygote”

Answer 9

The cell formed by the union of a male sex cell (a sperm) and a female sex cell (an ovum)

Question 10

Define “Embryo”

Answer 10

An organism in the early stages of growth and differentiation, from fertilization to the beginning of the third month of pregnancy (in humans).

Question 11

Define “Surface area to volume ratio”

Answer 11

The amount of surface area of an organism divided by its volume

Question 12

Define “Emergent properties”

Answer 12

An emergent property is a property that a collection or complex system has, but which the individual members do not have.

Example: The heart can pump blood. It is made up of heart cells, but the heart cells individually are unable to pump blood.

Question 13

Define “Tissue”

Answer 13

Tissue is a group of cells that have similar structure and that function together as a unit

Question 14

Define “Cell Differentiation”

Answer 14

The process during which young, immature (unspecialized) cells take on individual characteristics and reach their mature (specialized) form and function.

Question 15

Define “Gene Expression”

Answer 15

Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, protein or non-coding RNA, and ultimately affect a phenotype, as the final effect.

Question 16

Define “Diffuse”

Answer 16

Diffusion is the net movement of anything from a region of higher concentration to a region of lower concentration.

Question 17

Define “Stargardt’s Disease”

Answer 17

Stargardt’s generally refers to a group of inherited diseases causing light-sensitive cells in the inner back of the eye (retina) to deteriorate, particularly in the area of the macula where fine focusing occurs. Central vision loss also occurs, while peripheral vision usually is retained.

Question 18

Define “Stem Cell”

Answer 18

Stem cells are the body’s raw materials — cells from which all other cells with specialized functions are generated. No other cell in the body has the natural ability to generate new cell types

Question 19

Define “Pluripotent Stem Cell”

Answer 19

A stem cell that can turn into any cell type other than totipotent stem cells (cannot form the placenta).

Question 20

Define “Induced Pluripotent Stem Cell”

Answer 20

Induced pluripotent stem cells are a type of pluripotent stem cell that can be generated directly from a somatic cell.

Question 21

Define “Embryonic Stem Cell”

Answer 21

Embryonic stem cells are pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage pre-implantation embryo. Human embryos reach the blastocyst stage 4–5 days post fertilization, at which time they consist of 50–150 cells

Question 22

Define “Adult Stem Cell”

Answer 22

Adult stem cells are undifferentiated cells, found throughout the body after development, that multiply by cell division to replenish dying cells and regenerate damaged tissues. Also known as somatic stem cells, they can be found in juvenile, adult animals, and humans, unlike embryonic stem cells.

Question 23

Define “Blastocyst”

Answer 23

A structure formed in the early development of mammals. It possesses an inner cell mass (ICM) which subsequently forms the embryo

Question 24

Define “Somatic Cell”

Answer 24

A somatic cell, or vegetal cell, is any biological cell forming the body of a multicellular organism other than a gamete, germ cell, gametocyte or undifferentiated stem cell.

Question 25

Cell membrane

Answer 25

The cell membrane is a biological membrane that separates the interior of all cells from the outside environment which protects the cell from its environment. The cell membrane consists of a lipid bilayer, including cholesterols that sit between phospholipids to maintain their fluidity at various temperatures

Question 26

Steroid

Answer 26

any of a large class of organic compounds with a characteristic molecular structure containing four rings of carbon atoms (three six-membered and one five). They include many hormones, alkaloids, and vitamins.

Question 27

Embedded

Answer 27

fixed firmly and deeply in a surrounding mass; implanted.

Question 28

Hydrophobic

Answer 28

tending to repel or fail to mix with water.

Question 29

Hydrophilic

Answer 29

having a tendency to mix with, dissolve in, or be wetted by water.

Question 30

Amphipathic

Answer 30

(of a molecule, especially a protein) having both hydrophilic and hydrophobic parts.

Question 31

Phosphate head

Answer 31

A phosphate head is the “head” group of a phospholipid, the lipid that makes up the cell membrane lipid bilayer.

Question 32

Hydrocarbon

Answer 32

In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic with only weak odours. Because of their diverse molecular structures, it is difficult to generalize further.

Question 33

Phospholipid bilayer

Answer 33

The lipid bilayer is a thin polar membrane made of two layers of lipid molecules. These membranes are flat sheets that form a continuous barrier around all cells.

Question 34

Integral proteins

Answer 34

An integral membrane protein is a type of membrane protein that is permanently attached to the biological membrane. All transmembrane proteins are IMPs, but not all IMPs are transmembrane proteins. IMPs comprise a significant fraction of the proteins encoded in an organism’s genome.

Question 35

Peripheral proteins

Answer 35

Peripheral membrane proteins are membrane proteins that adhere only temporarily to the biological membrane with which they are associated. These proteins attach to integral membrane proteins or penetrate the peripheral regions of the lipid bilayer.

Question 36

Cholesterol

Answer 36

Cholesterol is any of a class of certain organic molecules. Cholesterol is a sterol, a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell membranes. When chemically isolated, it is a yellowish crystalline solid.