Cells And Tissues

Question 1

What are cells

Answer 1

The cell is the basic unit of all organisms
Has a highly organised structure which enables it to carry out its vital functions

Question 2

Key scientist of cell theory

Answer 2

Robert Hooke
Theodore Schwann
Matthias Schleiden
Rudolf Virchow

Question 3

Three principles of cell theory

Answer 3

All living things are made up of one or more cells
Cells are the most basic unit of structure and function in all living things
All cells are created by pre-existing cells

Question 4

Prokaryotic cells

Answer 4

Bacteria and Archaea.
Amongst the simplest of organisms and made of single cells (unicellular).
Cell membrane, cytoplasm, no membrane-bound organelles, and DNA is free-floating in cytoplasm.
Cell division by binary fission.
Most are 0.2-2.0 μm.

Question 5

Eukaryotic cells

Answer 5

Animal, Plant, Protist and Fungal.
More complex cells, made of many cells (multicellular).
Cell membrane, cytoplasm, cell organelles, and DNA within a nucleus.
Cell division by mitosis.
Most are 5-100 μm.

Question 6

Structure of organelles

Answer 6

Nucleus
Mitochondria
Ribosomes
Rough endoplasmic reticulum
Smooth endoplasmic reticulum
Golgi apparatus, and Golgi vesicles
Centrioles
Lysosomes

Question 7

Organism

Answer 7

An individual plant, animal or single-celled lifeforms

Question 8

Organelles

Answer 8

Specialised structures within the cell that have specific functions

Question 9

Cytoplasm

Answer 9

The fluid component of the cell, enclosed by the cell membrane and surrounding
the organelles

Question 10

Membrane

Answer 10

All membranes consist of a phospholipid bilayer together with proteins and other
components. They are selectively permeable and can control movement of substances across
the membrane as well as being the sites of many important processes in the cell

Question 11

Phospholipid

Answer 11

Large molecule formed from a glycerol molecule covalently bound to two fatty
acid molecules and a phosphate group

Question 12

Phospholipid bilayer

Answer 12

: A double layer of phospholipids with the hydrophobic tails arranged
towards the middle and the hydrophilic head group on the outside. Forms the basis of all biological membranes

Question 13

Hydrophlilic

Answer 13

Can interact with Water

Question 14

Hydrophobic

Answer 14

Repels water

Question 15

Erythrocytes

Answer 15

(red blood cells) carry oxygen around the body, by using haemoglobin. The cells lack a nuclei and most other organelles so it has more room for haemoglobin. They are flattened and biconcave in shape, which increases the surface area of the cell, allowing more efficient diffusion of oxygen. The elastic plasma membrane allows the cell to change shape and squeeze through narrow capillaries

Question 16

Neurones

Answer 16

nerve cells are highly specialised to enable them to conduct electrical impulses in the nervous system. The impulse occurs in one direction, with sensory neurones in the peripheral nervous system (PNS) conducting impulses towards the central nervous system (CNS), and motor neurones conducting impulses away from the CNS

Question 17

Squamous Epithelial Cells

Answer 17

most important feature is that they are flattened cells, supported by a basement membrane, which makes up the epithelium. They are well suited to exchange surfaces, such as in the lungs. The basement membrane is a thin layer of protein fibres and polysaccharides which help support the epithelium (it is not a phospholipid bilayer like cell membranes)

Question 18

Erythrocytes

Answer 18

Carry oxygen haemoglobin it lacks a nuclei they are flattened and bisonaux this increases its surface area it can also change shape which allows it to squeeze through narrow capillaries

Question 19

Neurones

Answer 19

Sensory neurones- peripheral nervous system (PNS)
Central nervous system (CNS)
Motor neurones

Question 20

Squamous epithelial cells

Answer 20

Flattened cues supported by a basement membrane - the basement is a thin layer of protein fibres

Question 21

Totipotent

Answer 21

Can divide to produce any body cell

Question 22

Pluripotent

Answer 22

Found in embryos can divide and create tumours

Question 23

Multipotent

Answer 23

Found in mature mammals (adults) CG bone marrow can differentiate into limited number of cells- can differentiate late into limited number of cell- can. Differentiate I to erythrocytes (erythropoiesis)

Question 24

Endoderm

Answer 24

Lungs, liver, pancreas, small intestine, large intestine, stomach

Question 25

Mesoderm

Answer 25

Muscle, bone, heart cell, inner lining of skins, kidneys, bladder, ovaries, testicles

Question 26

Ectoderm

Answer 26

Outer layer of skin- sweat glands, hair, nervous system

Question 27

Specialised blood cells

Answer 27

Haemotoposes (haem=blood) haemotopolleic stem- found in bone marrow in adults (lymphopolesis)

Question 28

Embryos

Answer 28

Up to 16 days after fertilisation

Question 29

Umbilical cord blood

Answer 29

Contains multi potent

Question 30

Placenta

Answer 30

Can develop into limited number of specialised cells

Question 31

Adult stem cells

Answer 31

Bone marrow= repair

Question 32

Epigenetic’s

Answer 32

is the study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself In its modern sense, epigenetics is the term used to describe inheritance by mechanisms other than through the DNA sequence of genes

Question 33

Mitosis

Answer 33

is a process where a single cell divides into two identical daughter cells

Question 34

Stages of mitosis

Answer 34

Prophase: the stage in which chromosomes become visible and the nuclear envelope disappears Metaphase: the chromosomes arrange themselves at the centre of the cell Anaphase: each of the two threads of chromosomes (chromatid) migrates to the opposite pole Telophase: the nuclear envelope reforms to produce two daughter cells

Question 35

What does PMAT stand for

Answer 35

Prophase Metaphase Anaphase Telophase

Question 36

Stages of the cell cycle

Answer 36

Interphase Mitosis Cytokinesis

Question 37

Prokaryotic

Answer 37

Bacteria

Question 38

Eukaryotic

Answer 38

Animal Plant

Question 39

Haematopoiesis

Answer 39

A pathway where haematopoietic stem cells, which are found in the bone marrow of adults, can differentiate into blood cells.

Question 40

Mitosis

Answer 40

is a process where a single cell divides into two identical daughter cells.

Question 41

The cell cycle

Answer 41

is a series of events that take place in a cell, as it grows and divides.

Question 42

Stages of the Cell Cycle

Answer 42

• Interphase • Mitosis and Cytokinesis

Question 43

Standard Form

Answer 43

A standardised system of writing numbers, which is useful when working with a very large and small numbers.

Question 44

Three key types of microscopes

Answer 44

• Optical (Light) Microscope • Transmission Electron Microscope • Scanning Electron Microscope

Question 45

Light Microscope

Answer 45

• The light microscope is used to visualise small structures and samples by magnifying image of how they interact with visible light, e.g. reflect, absorb or scatter • Used to visualise fine detail of an object, reading a magnified image through a series of glass lenses, which first focus a beam of light onto or through an object, and convex objective lenses to enlarge the image formed • Poorer resolution to electron microscopes, due to light having longer wavelength • Lower magnification • Colour images • Can view living samples

Question 46

Electron Microscope

Answer 46

• A beam of electrons condense by electromagnets to create an image • Has a higher resolving power due to electrons having a short wavelength • Higher magnification • Black and white images • Samples placed in vacuum, therefore non-living

Question 47

Magnification

Answer 47

is how many times bigger the image of a specimen observed is in comparison to the actual size of the specimen.

Question 48

Calculating Magnification

Answer 48

Magnification =Size of image divided by Size of object

Question 49

Eyepiece Graticule

Answer 49

• When looking through an optical microscope, there is a scale on a glass disc known as the eyepiece graticule • This helps when measuring the size of objects being viewed under the microscope • This needs to be calibrated each time you change the objective lens and magnification • To calibrate, you use a stage micrometre

Question 50

Calculating TOTAL Magnification

Answer 50

Eyepiece Lens x Objective Lens =Total Magnification