Cells And Tissues

Question 1

What are the 7 characteristics of living ?

Answer 1

-breathing/ respiration (ATP <—> ADP)
-grow/develop
-reproduce
-move/locomotion
-excrete
-feed (heterotrophic, autotrophic)
-responsive

Question 2

What is ATP

Answer 2

ATP = adenosine triphosphate
It is the energy used by an organism in its daily operations.

After a simple reaction ATP breaks down to ADP (adenosine Diphosphate). The energy released from the breaking down of a molecular bond is the energy we use to keep ourselves alive.

Question 3

What is the function of the rough endoplasmic reticulum (RER)

Answer 3

Synthesis and transport of proteins in conjunction with the attached ribosomes.

Question 4

What is the function of the smooth endoplasmic reticulum (SER)

Answer 4

Synthesis and transport of lipids.

Question 5

What is the function of the nucleus ?

Answer 5

It’s the information center of the cell.
largest organelle, readily visible.

The nucleous forms part of the nucleus and contains RNA.
The nucleus contains DNA and proteins.

Question 6

What is cytoplasm ?

Answer 6

Aqueous material found within the cell.
Contains: nucleus, organelles and dissolved solutes (glucose, ions, ATP).

Question 7

What is the function of the Golgi body?

Answer 7

Consists of flattened membrane sacs. Involved in the production of lysosomes, secretory granules and plasma membrane.
Responsible for the transport and modification of substances such as glycoproteins.

Question 8

What is the function of the cell membrane?

Answer 8

Outer covering of the cell composed of phospholipid.
The cell membrane is semi-permeable and controls entry and exit of materials/molecules.

Question 9

What is the function of the secretory vesicle ?

Answer 9

Contains hormones that have to be transported from one cell to the other.

Question 10

What are the function of ribosomes ?

Answer 10

Spherical.
Can float free or be associated to E.R.
Responsible for protein synthesis

Question 11

What is the function of centrioles (paired) ?

Answer 11

Clearly visible during cell division
Responsible for spindle formation
(Nerve cells have no centrioles).

Question 12

Where does respiration start ?

Answer 12

Respiration starts in the cytoplasm and finishes in the mitochondria

Question 13

Define tissues.

Answer 13

Tissues = a functional mass of one or more type of cell.

Tissue types inc- epithelial, connective, skeletal and muscle nerve.

Question 14

About epithelial tissue

Answer 14

It is one of the simplest forms of animal tissues but shows how individual cells can be built into tissues of varying complexity.

Cover inner and outer surfaces of body (e.g- skin, organs, body cavities and blood vessels).

Types- simple and complex (stratified)

Simple = 1 cell thick

Complex (stratified) = more than 1 cell thick.

Question 15

Describe how tissues function to protect

Answer 15

-protect organs from dehydration
-mechanical injury
-microbial invasion

Question 16

Describe how tissues function to absorb

Answer 16

-provides a barrier to help/hinder movement of materials.

Question 17

Describe how tissues function for sensation

Answer 17

-most nerve endings terminate in epithelium

Question 18

Describe how tissues function for secretion

Answer 18

-Specialised cells produce a discharge = GLANDS

Question 19

Describe how tissues function for excretion

Answer 19

-removing material from body. E.g- specialised cells in kidney

Question 20

Describe how tissues function for surface transport (CILLIA)

Answer 20

-Cillia beat rhythmically to sweep material along.

Question 21

Name types of simple epithelia

Answer 21

-squamous
-cuboidal
-columnar
-ciliated
-pseudostratified

Question 22

Name types of complex epithelia

Answer 22

-named according to shape of cell

-Stratified cuboidal (sweat gland)
-stratified Squamous (oesophagus)
-Stratified columnar (mammary)
-stratified transitional (bladder)

May remain uncornified (unthickened)
E.g- lining of oesophagus
If cornified the squames become a dead horny layer of keratin (e.g skin)

Question 23

What is Stratified epithelium (skin) ?

Answer 23

-forms a tough impervious barrier
-cells formed by mitosis from germinal (base) layer
-First cells formed are cuboidal (as they push outward they flatten to become squamous).

Question 24

What is connective tissue?

Answer 24

-holds together; connects and supports the body plus acts as a transport system.
-forms a boundary between organs.

Includes:
-loose connective tissue: areolar and adipose (fat)
-Dense connective tissue: tendons and ligaments

Other connective tissues inc
-cartilage
-bone
-blood.

Question 25

What are the main fibres found in connective tissue?

Answer 25

-collagen: strong, flexible, INELASTIC (bones, tendons)

-Elastin: strong, flexible, elastic.

Question 26

What is adipose tissue?

Answer 26

Similar to areolar tissue

Contains numerous closely packed fat cells

Main functions are energy store, insulation and protection.

Question 27

What is dense connective tissue?

Answer 27

Tissue contains more fibres than cells.

2 types of fibres:
1. Regular- orientated to run parallel
2. Irregular- randomly arranged.

Question 28

White fibrous dense connective tissue

Answer 28

-tough shiny tissue

-numerous bundles of collagen (fibres run parallel)

-strong, flexible but inelastic. Found in tendons.

Question 29

Yellow elastic dense connective tissue

Answer 29

A loose network of irregularly arranged branched yellow fibres.

=flexible, elastic tissue with strength

Found in: ligaments, walls of arteries, cords in neck.

Question 30

Body cavities

Answer 30

Body is divided into 3 distinct cavities (not true cavities as filled with visceral structures and a little fluid)

-Thoracic cavity
-Abdominal cavity
-Pelvic cavity

All cavities are lined with a serosal membrane.

Question 31

What does the serosal membrane do?

Answer 31

• the serosal membrane secretes fluid.

Serosal membrane apposing boundary of cavity = parietal
(E.g- parietal pleura or parietal peritoneum)

serosal membrane apposing organs within cavity = visceral
(E.g- visceral pleura or visceral peritoneum)

Question 32

About the Thoriac cavity…

Answer 32

-divided into right and left pleural cavities by a double layer of pleura called the mediastinum

-mediastinum contains pericardial cavity surrounding the heart.

-Each pleural cavity contains a lung and small amount of pleural fluid.

Question 33

About the abdominal cavity…

Answer 33

-serous membrane = peritoneum forms a continuous sheet forming a closed cavity (peritoneal cavity)

-abdominal cavity filled with abdominal viscera (organs)

-peritoneal cavity only contains a little fluid- NO ORGANS.