Bk 1 Ch 2 intro cell diversity

Question 1

Morphology

Answer 1

The form or structure of an organism or a cell.

Question 2

Colony

Answer 2

Group of individual organisms linked together either by living extensions of their bodies (e.g. cytoplasmic strands) or by nonliving material that they have excreted.

Question 3

Cell morphology

Answer 3

Structure or form of cells – important role in cell function.

Question 4

Differentiation

Answer 4

Process by which cells become specialised

Question 5

Resolution

Answer 5

The smallest distance between two objects that can be distinguished by a particular type of microscopy.

Question 6

Ultrastructure

Answer 6

Fine structure of a cell that can only be seen using an electron microscope.

Question 7

Histochemistry

Answer 7

The technique by which chemical staining is used to identify different elements within tissues. There are many different histochemical stains.

Question 8

Immunohistochemistry

Answer 8

technique that uses antibodies to attach to, and hence locate, specific molecules in tissues. The bound antibodies are detected by direct or indirect conjugation to an enzyme that produces a colour reaction or to a fluorescent molecule (also see immunocytochemistry)

Question 9

Immunocytochemistry

Answer 9

A technique that uses antibodies to attach to, and hence locate, specific molecules in cell preparations (e.g. cell cultures). The bound antibodies are detected by direct or indirect conjugation to an enzyme that produces a colour reaction or to a fluorescent molecule (also see immunohistochemistry).

Question 10

Antigen

Answer 10

Any molecule (or part of a molecule) that can generate an immune response. Antigens may or may not be on the surface of cells.

Question 11

Substrate

Answer 11

The chemical upon which an enzyme acts is known as the substrate. The substrate binds to a binding site on the enzyme and is chemically transformed to form a product or products.

Question 12

Antibodies

Answer 12

Y shaped proteins produced by immune system of vertebrates in response to invasion by foreign material eg bacteria or viruses. They recognise and bind specifically to one particular molecule or part of a molecule (antigen)

Question 13

Flourophore

Answer 13

Chemical emits fluorescent light of particular colour when illuminated with light specific wavelengths. Viewed using a specialised fluorescence microscope. Used to label a secondary antibody that recognises the primary Antibody bound to the antigen

Question 14

Confocal microscope

Answer 14

Allows image of fluorescent labelling to be captured at different levels within a sample. Allows very detailed analysis and even three-dimensional reconstruction by computer of labelled cells and then tissues

Question 15

Primary cells

Answer 15

Cultured cells derived from a fresh tissue sample. They are only able to divide a certain number of times in culture.

Question 16

Cell lines

Answer 16

A source of so called ‘immortal’ cells consisting of homogenous populations of cells typically derived from tumours with the ability to continue to divide indefinitely.

Question 17

Pili

Answer 17

(Sing. pilus) Short, thin, hair-like appendages on the surface of many bacteria. Pili are made of protein and are prinicipally involved in adhesion to other cells or surfaces. Sex pili are involved in the transfer of genetic material between bacterial cells during conjugation.

Question 18

Endocytosis

Answer 18

The general term applied to the uptake of materials into cells, by invagination of and engulfment by the cell membrane. When solid particles are taken up the process is called phagocytosis.

Question 19

Pseudopodia

Answer 19

Extended lobe of cytoplasm from a flexible cell surface. Enables endocytosis and form of movement known as amoeboid movement on a solid surface.

Question 20

Unicellular

Answer 20

An organism consisting of a single cell

Question 21

Multicellular

Answer 21

An organism that consists of many cells which may be of several types, specialised to perform different functions.

Question 22

Cell wall

Answer 22

Rigid structure secreted outside the cell membrane has encloses and protects the cell; found in most algae bacteria and all plants and fungi never in animals

Question 23

Cell membrane

Answer 23

The outer membrane of cells, compose largely of phospholipids, often called the plasma membrane in animals and the plasmalemma in plants

Question 24

Ground tissue

Answer 24

One of three main tissue types in flowering plants. It provides packing and support, and also energy storage, and includes the majority of photosynthetic cells (palisade cells), which are located in the interior of leaves.

Question 25

Vascular tissue

Answer 25

One of the three main tissue types in flowering plants comprising xylem, which transports water and dissolved ions from the roots to the rest of the plant and phloem, which transports the products of photosynthesis around the plant.

Question 26

Dermal tissue

Answer 26

One of the three main tissue types in flowering plants. It is the outer cell layer and provides protection, and controls uptake of water, nutrients and gases, in different parts of the plant.

Question 27

Neurodegerative

Answer 27

Inherited diseases-neurons degenerate in brain, >significant loss of muscle coordination and cognitive function eg Huntington’s disease and Parkinson‘s disease.

Question 28

Epithelial cells

Answer 28

Epidermis, lining of intestine (polarised -apical surface in contact w food. Basolateral surface in contact w other cells) blood vessels, lungs, cells of glands(eg mammary, saliva.

Protection, barrier, absorption, secretion.

Form sheets closely linked, polarised cells.

Question 29

Endocrine cells (hormone producing)

Answer 29

Pancreas, adrenal gland.

Widespread communication.

Produce and secrete chemical messengers into circulation.

Question 30

Muscle cells - smooth-muscle of internal organs

Answer 30

Intestines and blood vessels.

Involuntary control

Movement e.g. peristalsis.

Contains contractile proteins, linked together by gap functions

Question 31

Muscle cells skeletal muscle of limbs known as striatal muscle (stripes appearance)

Answer 31

Voluntary/conscious control.

Movement of limbs.

Contains contractile proteins, form a Syncytium of long multinucleate fibre like cells

Question 32

Muscle cells, cardiac muscle

Answer 32

Contraction of heart.

Contains contractile proteins

Question 33

Nerve cells (neurons)

Answer 33

Neurons of brain and spinal-cord,

small groups of neurons (ganglia) in body.

Rapid and specific communication.

Polarised cells with long processes, having special membrane properties that allow electrical signalling

Question 34

Supports cells (often classified as connective tissue cells)

Answer 34

Bone cells (osteoblasts and osteoclasts), cartilage, fibroblasts.

Provide support and help to organise tissue structure.

Fibroblasts produce much of the extracellular material - made of collagen, elastin.

Question 35

Adipocytes (often classified as connective tissue cells)

Answer 35

Adipose tissue around certain organs and underskin.

Energy storage, protection.

Have cytoplasm mostly composed of lipid

Question 36

Blood cells

Answer 36

Red blood cells (RBCs).

Oxygen transport.

RBCs contain haemoglobin which binds oxygen, Mammalian RBCs lose their nucleus when mature.

Question 37

Immune system cells

Answer 37

Leukocytes (several types). Lobed nuclei are neutrophils. Round nucleus is lymphocyte.

Defence.

B lymphocytes and plasma cells produce antibodies, macrophages ingest pathogens, etc.

Question 38

Germ cells

Answer 38

Eggs, sperm.

Reproduction.

Haploid (contain half the normal number of chromosomes)

Question 39

Polarised cell

Answer 39

Cell with different properties on 1 side than on the other

Question 40

Give examples of shapes exhibited by different bacterial species, and name one species of bacteria has exhibit each shape.

Answer 40

Round – e.g. Streptococcus pneumoniae and Thiomargarita namibiensis.

Rod shaped – E.g. Escherichia coli (E.coli)

Thread like (filamentous),
Spiral or corkscrew – shaped – e.g. Spirillum volutans and spirillum minus. 

Crescent – shaped - eg Caulobacter crescetus

Question 41

Name to specialise structures that extend from the cell membrane of some bacterial species

Answer 41

Flagellum (pl. flagella)

Pilus (pl. pili)

Question 42

State principal functions of Pilus and flagellum

Answer 42

Flagellum – so motility

Pilus – Adhesion to other cells or surfaces
Sex pili are involved in bacterial mating (conjugation)

Question 43

Name the three main types of tissue in flowering plants and their functions

Answer 43

Ground tissue - packing and support. Energy storage. Photosynthesis.

Vascular tissue - transport of water and nutrients

Dermal tissue. - protection. Control uptake of water nutrients and gases.

Question 44

For each type of plant tissue give examples of component tissue and cell type and function

Answer 44

Ground tissue – palisade cells (photosynthesis). Parenchyma cells (package and support.

Vascular tissue – xylem (water and ion transport). Phloem(transport of photosynthetic products).

Dermal tissue – epidermal cells form a barrier and control passage of water, nutrients and gases, including specialised guard cells which open and close the stomata.

Question 45

What are the functions of specialised vertebrate intestinal cells?

Answer 45

Smooth-muscle – contraction (peristalsis)
Fibroblasts (connective tissue cells) – support
Epithelial cells – absorption and secretion
Neurons – communication
Immune system cells – defence.

Question 46

Which sole type would be expected in abundance in the kidney, an organ in which excreted fluid flows passively through tubules that are specialised to reabsorbed useful molecules from the urine.?

Answer 46

Epithelial cells

Question 47

The pancreas is a gland that specialised to secrete peptide hormones (e.g. insulin), and also suggestive hormones (e.g. trypsin). What technique would be used to determine whether these two different secretory molecules are stored in the same or different cells of this organ?

Answer 47

Double immuno labelling of tissue sections (immunohistochemistry).

Question 48

The pancreas is a gland that are specialised to secrete peptide hormones (e.g. insulin), and also suggested enzymes (e.g. trypsin) what main reagents would be needed to perform double immunolabelling of tissue sections

Answer 48

1. Specific antisera that recognise each of the two molecules (one that recognises insulin and the second that recognises trypsin).
2. Two secondary antisera coupled to 2 different fluorescent markers (or enzymes that produce different coloured reaction products).
   Cells that contain both molecules will be double labelled, while those that contain only one of the two molecules will display a single fluorescence or colour reaction note that this technique does not prove these molecules are synthesise in the cells. In order to demonstrate synthesis of a molecule unambiguously it would be necessary to examine the mRNA content of the cells

Question 49

You’ve been provided with a light microscope and a microscopic slide on which cells been smeared. What features would identify or measure to determine whether the cells are eukaryotic or prokaryotic?

Answer 49

1. Cell size: most part of prokaryotic cells are much smaller than eukaryotic cells measuring 1 to 5 micro metres in diameter compared with the eukaryotic cell diameter of 10 to 100 micro metres. The sub cellular features of prokaryotic cells are therefore difficult to discern by light microscopy (LM).
2. Presence of nuclei: the nuclei of the eukaryotic cells are visible by LM.

Question 50

What is the result of Glycosylation of a protein

Answer 50

Glycoprotein