Cell Biology

Question 1

Organelles?

Answer 1

Organelles?

.Carry out particular functions in the cell. These are;

.Cell nucleus

.Cell cytoplasm

.Cell membrane/ plasma membrane

.Mitochondrion or mitochondria plural.

.Rough endoplasmic reticulum RER

.Smooth endoplasmic reticulum SER

. Ribosomes

.Centrosome

.Lysosomes

.Golgi body/ Golgi apparatus

Question 2

Cell nucleus?

Answer 2

Cell nucleus?

.Largest organelle. Contains a nucleolus (darkened spot).

.Contains the genetic material which determines the cell’s function.

Question 3

Cell cytoplasm?

Answer 3

Cell cytoplasm?

.Jelly-like, grandular substance.

.Provides a medium for all biochemical reactions in the cell and gives it shape.

Question 4

Cell membrane?

Answer 4

Cell membrane?

.Controls what enters and leaves the cell and has a bi-lipid membrane.

.A lipid bilayer.

Question 5

Mitochondrion?

Answer 5

Mitochondrion?

.The site of energy release from food consumed, digested and transported via the bloodstream.

Question 6

Rough endoplasmic reticulum?

Answer 6

Rough endoplasmic reticulum?

.Has ribosomes attached to the surface.

.Location for synthesis and then transport of substances including proteins when ribosomes are present.

Question 7

Smooth endoplasmic reticulum?

Answer 7

Smooth endoplasmic reticulum?

.No ribosomes attached to the surface and tubular in form.

.Location for synthesis of lipids and their transport; appear as a stack of plates.

Question 8

Ribosomes?

Answer 8

Ribosomes?

.Can be attached to endoplasmic reticulum or free in the cytoplasm.

.Site of protein synthesis when attached to endoplasmic reticulum.

Question 9

Centrosome?

Answer 9

Centrosome?

.Distinct area that organises centrioles.

.Location in the cytoplasm where centrioles are organised for cell division.

Question 10

Lysosomes?

Answer 10

Lysosomes?

.Single-membrane organelles containing special enzymes.

.Engulfs and digests old or damaged organelles; contains enzymes that breakdown organelles.

Question 11

Golgi body/ Golgi apparatus?

Answer 11

Golgi body/ Golgi apparatus?

.A stack of modified endoplasmic reticulum.

.Receives, modifies and packages substances to produces vesicles for their transport.

Question 12

Epithelial tissue?

Answer 12

Epithelial tissue?

.Overall purpose of epithelial tissue is to act as a lining tissue. It is found as a covering and lining tissue of body organs and structures.

.Also protects the inside of organs by providing a layer of tissue over the critical structures.

.There are single (simple epithelium) or layered sheets (stratified epithelial tissue).

.Epithelial cells are classified by their shape: there are squamous (pronounced skway – mus) cells – this isa flattened shape. There are cuboidal or, cube shaped cells. Columnar are tall and column-shaped cells.

Question 13

Simple epithelial tissue types?

Answer 13

Simple epithelial tissue types?

.Simple squamous - is a single sheet of flattened cells. To provide a smooth but thin protective lining within or around an internal body structure and permit dissolved substances to pass through it. Within the Bowman’s capsule of the kidney nephrons, the lining of alveoli in the lungs and the lining of capillaries.

.Simple cuboidal - is a single sheet of cube-shaped cells. To provide a line internal structures of organs for protection and to secrete lubricating substances.Over the surface of the ovaries in female animals, the kidney tubules and within secreting parts of glands.

.Simple columnar - is a single sheet of column-shaped cells.

.Ciliated epithelial tissue - is a single sheet of cells with tiny hair-like projections.To move particles along within certain structures of the body from one location to another with the addition of goblet cells that secrete fluids. Within the lining of the oviducts in female animals and the trachea.

Question 14

Stratified epithelial tissue types?

Answer 14

Stratified epithelial tissue types?

.Stratified epithelial tissue - stratified epithelium has several layers (it has irregular shaped columns/cubes). To provide a relatively tough and impervious barrier where areas of friction occur within the organs and structures of the body and at the outer surface.The lining of the oesophagus, the external skin surface, the buccal cavity (mouth) and vagina in females.

.Transitional epithelium

.Glandular epithelium - has several layers (highly specialised). To provide a means of manufacturing, storing and secreting liquid and other substances into the bloodstream, over the epithelial cell itself or through a duct. Within the endocrine and exocrine glands where substances can be manufactured, stored and secreted.

Question 15

Epithelial cells are classified by their?

Answer 15

Epithelial cells are classified by their?

.Their shape: there are squamous (pronounced skway – mus) cells – this is a flattened shape.

There are cuboidal or, cube shaped cells. Columnar are tall.

Question 16

Muscular tissue?

Answer 16

Muscular tissue?

.To aid locomotion and internal movement of body organs and structures.

.Muscles have the main function or purpose of allowing movement (locomotion) by some sort by contraction and expansion.

.When attached to bones, they allow a joint to return to its original position and in internal organs, they allow the smooth expansion and contraction of digestive system structures (e.g. the intestines, stomach and oesophagus).

.The specialised cardiac muscle tissue acts to allow the rhythmic steady beat of the heart.

Question 17

Skeletal muscle tissue?

Answer 17

Skeletal muscle tissue?

.Attached to the skeleton and is controlled voluntarily.

.Skeletal muscle cells are shaped like cylinders and are called muscle fibres. The fibres are arranged in bundles and layers and so this muscle tissue type is called “striated”.

.The striations are composed of myosin (a protein that forms the thicker component of the cylindrical filament); and actin (a protein that forms the thinner component of the filament). These two proteins permit elasticity for contraction and relaxation of the fibres.

.Skeletal muscle tissue is formed from closely-packed bundles of fibres without the “gaps” shown in the cardiac muscle diagram.

Question 18

Smooth muscle tissue?

Answer 18

Smooth muscle tissue?

.It is located throughout the body in areas such as the oesophagus, bladder and digestive system.

.Spindle shaped cells which are arranged in sheets or bundles. Smooth muscle is under involuntary control.

.This sheet-like formation together with no striations allows smooth wave-like movement (peristalsis) and a stretching ability greater than that available to skeletal muscle. Its elasticity is considerable.

.This muscle tissue can stretch extensively as well as perform what is known as peristalsis because of the sheet like formation, also having no striations it allows smooth like movement in the cell.

Question 19

Cardiac muscle?

Answer 19

Cardiac muscle?

.Has a structure similar to skeletal muscle but it functions in a very different way.

.The heart contains only cardiac muscle. The tissue’s structure is necessary for this organ because it has intercalated discs that allow the heart to expand and contract when they get
electrical impulses from the nervous system which makes the heart pump blood around the body regularly and effectively.

.This muscle tissue is also under involuntary control. Cardiac muscle has structures called intercalcated discs that link the muscles fibres.

.Their purpose is to allow cardiac muscle to contract in a synchronised

Question 20

Nervous tissue?

Answer 20

Nervous tissue?

.Provide a means of sending and receiving electrochemical signals from a stimulus to allow the animal to respond to changes in and outside its environment.

.Is perhaps the most complex tissue type and the most difficult to repair if damaged.

.The purpose of nervous tissue is to detect stimuli and respond by transmitting information along nerve fibres. This is achieved by means of electrochemical signals (nervous impulses).

.The nervous system of any vertebrate consists of the CNS (Central Nervous System) made up of the brain and spinal cord.

.The PNS (Peripheral Nervous System) is made up of all nervous tissue extending from the spinal cord to the limbs and internal and external organs.

.Electrochemical signals generated by the nervous system pass from neurone to neurone via a synapse after travelling along the a “process”. This process is the axon. To protect the axon (this can be likened to a tiny piece of electrical wire) an insulating layer called the myelin sheath covers whole process. The myelin sheath does not insulate to keep the axon warm! It insulates like the coating over an electrical wire – it maintains the health electrical signal.

Question 21

Connective tissue?

Answer 21

Connective tissue?

.To provide a means of linking, supporting and surrounding body organs, the body as a whole and binding other tissues together.

.Connects one organ to another and, connects spaces so that organs can work properly. Can be loose (areolar) or dense (compact) connective.

Question 22

Dense connective tissue?

Answer 22

Dense connective tissue?

.Provide a tough, robust, strong and flexible material to allow efficient movement of different structures such as tendons, ligaments, cartilage and artery walls.

Question 23

Blood?

Answer 23

Blood?

.Is found within the circulatory system and contains erythrocytes (red blood cells), leucocytes (white blood cells), platelets and plasma.

.Plasma is the liquid component of blood and comprises the biggest volume in a blood sample.

Question 24

White blood cells?

Answer 24

White blood cells?

.Lymphocyte

.Monocyte

.Neutrophil

.Eosinophil

.Basophil

Question 25

The overall purpose and function of epithelial tissue?

Answer 25

The overall purpose and function of epithelial tissue?

.To act as a lining tissue for body cavities, within organs and structures.

Question 26

Dendrites?

Answer 26

Dendrites?

.Their purpose is to move impulses toward the cell body.

Question 27

The synapse?

Answer 27

The synapse?

.The synapse is so important for the nervous tissue because it transports the electrical signals from neuron to neuron.

Question 28

The myelin sheath?

Answer 28

The myelin sheath?

.The function is to protect the axon with an insulating layer and to maintains the health electrical signal.

Question 29

Cartilage types and location?

Answer 29

Cartilage types and location?

.Elastic - found for example, at the end of the bones and within the ear.

.Hyaline - found for example, in the pharynx.

.Fibrocartilage - found for example, between the vertebrae.

Question 30

Description and function for Fibroblasts, chondrocytes and macrophages?

Answer 30

Description and function for Fibroblasts, chondrocytes and macrophages?

.Cells that produce the fibres that form collagen for the matrix and repair damaged connective tissue.

Question 31

Connective tissue has no blood supply. How then does connective tissue receive all the nutrients it needs and remove waste products? Which process is involved?

Answer 31

Connective tissue has no blood supply. How then does connective tissue receive all the nutrients it needs and remove waste products? Which process is involved?

.Simple diffusion down a concentration gradient.

Question 32

Adipose tissue?

Answer 32

Adipose tissue?

.Composed of fat filled cells containing fat globules.

.The functions of adipose tissue are to protect and insulate the body and store energy in the form of fat food.

.Found around blood vessels and nerves, beneath the skin, between connecting organs and between muscle bundles.

Question 33

Loose connective tissue?

Answer 33

Loose connective tissue?

.Located beneath the skin, connecting organs and between spaces.

.Fibroblasts, macrophages, collagen and elastic fibres comprise loose connective tissue.

.Link, support and connect internal organs, blood vessels and nerves connecting these to the skin, filling spaces between different organs and binding epithelial sheets to form mesenteries.

Question 34

Cartilage?

Answer 34

Cartilage?

.Cartilage - is a tough connective tissue and it is formed from as matrix of chondrin, chondrocytes and collagen fibres which provides support and strength.

.Cartilage has no blood supply and relies on surrounding tissues for its oxygen, other nutrients and removal of harmful substances.