Cell Function And Hoeostasis

Question 1

What is the role of the nucleus

Answer 1

Largest organelle all cells but red blood cells contains genetic material

Question 2

What is the role of the plasma membrane

Answer 2

Controls the passage of the substance in and out of the cell regulating environment

Question 3

What is the role of a ribosome

Answer 3

Synthesises protein from amino acids using RNA templates

Question 4

What is the role of mitochondria

Answer 4

Makes all our energy -involved in aerobic respiration with o2 and ATP

Question 5

Centrioles

Answer 5

Produces cellular spindles in mitosis as well as making micro tubules

Question 6

Chromatin

Answer 6

Helps compact dna from longer strands into smaller packages as part of mitosis

Question 7

Lysosome

Answer 7

Small membranous vesicles containing enzymes

Question 8

Golgi apparatus

Answer 8

Synthesised protein are packed and stored here

Question 9

Endoplasmic reticulum

Answer 9

Smooth- involved in making lipids breaking down co2 and storing calcium
Rough- ribosomes on its surface to make and modify proteins

Question 10

What are the 3 ways that substances are moved through the cellular membrane and in and out of the cell

Answer 10

Diffusion
Osmosis
Active transport

Question 11

Describe osmosis

Answer 11

Movement of water down a concentration from an area of high concentration to low concentration

Question 12

Describe diffusion

Answer 12

Movement of molecules from an area of high concentration to an area of low concentration

Question 13

Active transport

Answer 13

Transport substances up the concentration gradient requiring energy and carriers
Eg sodium/ potassium pump
Potassium levels higher in the cell and sodium levels higher outside the cell
Particles are transported through phagocytosis

Question 14

What are the 6 different cell actions

Answer 14

Reproduce
Nourishment
Movement
Excretion
Growth
Respiration

Question 15

Role of red blood cells

Answer 15

Carry oxygen

Question 16

Kindney tubules cells roles

Answer 16

Controls water and salt excretion

Question 17

Kindney tubules cells roles

Answer 17

Controls water and salt excretion

Question 18

Cardiac cells roles

Answer 18

Contract and controls heart pumping

Question 19

Cartilage function

Answer 19

Structural support

Question 20

Neurone function

Answer 20

Conducts electrical impulse (message )

Question 21

Sperm

Answer 21

Convery genetic material for reproduction

Question 22

Describe cellular tissues

Answer 22

Groups of similar cells are tissues

Question 23

What are the 4 basic tissue types

Answer 23

Connective tissues - binding supporting protecting eg cartilage, blood, bone
Epithelial tissues- cells forming continuous sheets often lining body cavities eg skin gut lining and glands
Muscle tissues-skeletal muscles under voluntary control attached to bone for motion/posture
Smooth muscles forming walls of tubes e.g airways, blood vesicles, gut , bladdder ,
Cardiac muscles under involuntary control causing heart to pump
Nervous tissues- Neurone conduct electrical impulses throughout the body eg brain and spinal cord to control body.

Question 24

How is an organismal made

Answer 24

Group of similar cells= tissues
Group of tissues = organs
6 levels of organisation
Organs - grouping of 2 or more tissues types into recognisable structure with a specific function
System- collection of related organs with a common function
All the systems makes an organismal

Question 25

Cell suicide apotosis

Question 26

Cell damage/disease

Answer 26

Necrosis

Question 27

Lifecycle of most cells

Answer 27

Some continuously replaced Continuous apotosing and replaced by mitosis Gut epithelium -turnover 3 days Skin epidermis-turnover 2-4 weeks Some cells never replaced they die eg. Muscles and nervous system 50 percent of cells die by the time we are old

Question 28

Stages of apoptosis

Answer 28

Normal cell The cell shrinks and chromtins condenses Membrane start blebbing organelles disintegrates Nucleus and organelles collapse membrane continue to bleb Apoptotic bodies form Macrophages phagocytose apoptotic bodies

Question 29

Problem with aging

Answer 29

Mitosis slows down so cells that die are not replaced leading to signs of aging Reduced numbers of immune cells lead to increased risk of infection

Question 30

Problems with apoptosis

Answer 30

It can increase in some cells causing diseases eg alzheimer where valuable nerves cells die more quickly Apoptosis can stop causing cells to over divide and form tumours

Question 31

What is homeostasis

Answer 31

Organism is in homeostasis when conditions in the internal environment are maintained within physiological limits. When homeostasis is disturbed illness may result. Body fluids and cells are not bought back into homeostasis. Death occurs.

Question 32

What must be kept constant to protect the cells

Answer 32

Chemical constitution eg glucose, ions, ph , temperature, osmotic pressure, eg water and solute concerntratuons o2/ co2 levels

Question 33

How does homeostasis work

Answer 33

Receptors cable of detecting changes in body By having control systems- to initiate corrective measures. Usually a nerve centre Effectors carry out corrective measures

Question 34

Negative feedback

Answer 34

Response reverses original stimulus - reworks normal levels

Question 35

Positive feedback

Answer 35

Response enhances original stimulus eg continues to reinforce the original stimulus