1. CYTOLOGY, GENETICS AND HISTOLOGY COPY

Question 1

Blood plasma, synovial fluid, lymph fluid and interstitial fluid are all examples of _____________ fluids

Answer 1

extracellular

Question 2

Name four things that can cause oxidative damage in the body

Answer 2

Stress, smoking, toxins, diet high in refined foods and sugar

Question 3

What are free radicals and how can they be countered in the body?

Answer 3

Free radicals are unstable and highly reactive molecules. They lack an electron in their atomic structure, which can be donated by antioxidants such as Vitamin A, C, E, beta-carotene (Vitamin A precursor), quercetin and lycopene.

Question 4

What are the main differences between prokaryotic and eukaryotic cells?

Answer 4

Prokaryotic cells contain no nucleus and no membrane bound internal structures, while eukaryotic cells have both.

Question 5

True or false:

Only prokaryotic cells have cell walls.

Answer 5

False: Plants and fungi are eukaryotes and their cells have cell walls.

Question 6

Differentiate between ’cytosol’ and ‘cytoplasm’ by defining them.

Answer 6

Cytosol is the basic watery fluid inside a cell. Cytoplasm is the cell content excluding the nucleus (cytosol + organelles)

Question 7

The cell membrane is a ________, semi-_________ membrane that separates the cell’s ________ and internal environment.

Answer 7

Flexible
Permeable
External

Question 8

Briefly describe the structure of the cell membrane

Answer 8

The cell membrane is a phospholipid bilayer, these being arranged with the hydrophilic phosphate heads towards the outsides and the hydrophobic lipid tails on the inside.

Question 9

Cell membranes are embedded with _____________ proteins and controls substance ________ in and out of cells.

Answer 9

Transmembrane

Movement

Question 10

What are the functions of transmembrane proteins?

Answer 10

1. Transport of substances in/out of cells (e.g. charged particles like hydrogen and larger molecules like glucose)
2. Immunological identity: helps immune cells recognise our own cells
3. Receptors: recognition sites for hormones etc.

Question 11

Name two places in the body where tight cell junctions can be found

Answer 11

Stomach
Intestines
Bladder

Question 12

Name five of the key organelles found in body cells

Answer 12

Nucleus (with nucleolus)
Mitochondria 
Ribosomes 
Endoplasmic reticulum 
Golgi apparatus 
Lysosomes 
Cytoskeleton

Question 13

All body cells have a nucleus with the exception of _____________________.

Answer 13

Red blood cells

Question 14

The nucleus is a spherical structure that contains the body’s _______ information in the form of ___. It controls all cell functions, hence known as the _____ of the cell. It contains a _________, which produces RNA.

Answer 14

Genetic
DNA
Brain
Nucleolus

Question 15

What organelle is continuous with the nuclear membrane?

Answer 15

Rough endoplasmic reticulum

Question 16

DNA forms a double _____ which coils around proteins called ________.

Answer 16

Helix

Histones

Question 17

What is the complete set of chromosomes from a cell called?

Answer 17

Its karyotype

Question 18

By which process do prokaryotic cells divide?

Answer 18

Binary fissure (rapid mitosis)

Question 19

In the cells of which body cells are the most mitochondria found?

Answer 19

Liver, muscle and spermatozoa

Question 20

What is the cytoskeleton of the cell and what is its function?

Answer 20

The cytoskeleton is a network of protein filaments (microtubules and microfilaments) that extends throughout the cytosol that assists with:

1. Generating cell movement- enable white blood cells to migrate to sites of injury and enable muscle contraction
2. Physical support and shape of the cell
3. Cell division - they move chromosomes apart (as the mitotic spindle)

Question 21

What is the energy currency of the cell that is produced by mitochondria

Answer 21

ATP (adenosine triphosphate)

Question 22

Finish the following ‘aerobic respiration’ equation:

Glucose + ______ = carbon dioxide + water + ___

Answer 22

Oxygen

ATP

Question 23

What is the function of ribosomes in the cell and in which two places can they be found?

Answer 23

Ribosomes act as the site of protein synthesis (their name reflects their high content of ribonucleic acid). They are either mobile (free in cytoplasm - make proteins for use inside the cell) or stationary (bound to rough endoplasmic reticulum - make proteins for outside the cell).

Question 24

What is the rough endoplasmic reticulum and what is its function?

Answer 24

It is a network of membranes in the form of flattened sacs that is continuous with the nuclear envelope, is studded with ribosomes and extends throughout the cytoplasm to the cell membrane. It synthesises and transports proteins out of the cell.

Question 25

What is the role of the smooth endoplasmic reticulum?

Answer 25

It contains unique enzymes and

1. synthesises lipids and steroid hormones (eg. oestrogen)
2. In the liver it detoxifies alcohol and drugs
3. In muscles, it releases calcium for muscle contraction.

Question 26

What is the function of the Golgi apparatus in the cell?

Answer 26

The Golgi apparatus modifies, sorts, packages and transports proteins received from the rough ER. The membrane-bound vesicles of proteins created are stored, and when needed are moved to the plasma membrane before fusing with it and then expelling it from the cell in a process known as exocytosis. It can be likened to the cell’s Post Office.

Question 27

What are lysosomes?

Answer 27

Lysosomes are small membranous vesicles that are pinched off from the Golgi apparatus. They contain as many as 60 powerful enzymes which engulf and digest fragments of organelles and large molecules (e.g. RNA, DNA, carbs and proteins) inside the cell that are either recycled or exported from the cell as waste material. Lysosomes in white blood cells digest foreign materials like microbes, and in sperm it releases enzymes externally to assist egg entry.

Question 28

Which body cells never undergo mitosis?

Answer 28

Neurons

Question 29

How long does it take the following cells and organs to replace themselves:

1. Skin
2. Stomach and intestinal mucosa
3. Liver
4. Red blood cells
5. Taste buds

Answer 29

1. 40 days
2. 5 days
3. 5 months
4. 90-120 days
5. 10 days