Cell Function And Homeostasis

Question 1

What is the function of the nucleus

Answer 1

Largest organelle which is within all cells (minus rbcs) and it contains genetic material

Question 2

What is the function of plasma membrane

Answer 2

Controls the passage of substances in and out of the cell regulating intracellular environment

Question 3

What is the function of the ribosome

Answer 3

Synthesise protein from amino acids using RNA template

Question 4

What is the function of mitochondria

Answer 4

Aerobic respiration with O2 and ATP ( which can be used to make energy)

Question 5

What is the function of smooth endoplasmic reticulum

Answer 5

Synthesis lipids and steroids hormones

Question 6

What is the function of rough endoplasmic reticulum

Answer 6

Studded with ribosomes which synthesis protein and leave by exocytosis

Question 7

What is the function of the Golgi apparatus

Answer 7

Synthesised proteins are packaged and stored here

Question 8

What is the function of lysosome

Answer 8

Small membranous vesicles containing enzymes

Question 9

What is the function of chromatin

Answer 9

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

Question 10

What is the function of centrioles

Answer 10

Are responsible for producing cellular spindles in mitosis as well as making micro tubules

Question 11

What are the three ways that substances can move through the cell membrane

Answer 11

Osmosis, diffusion and active transport

Question 12

What is the definition of osmosis

Answer 12

Movement of water from and area of high concentration to an area of low concentration ( down a concentration gradient)

Question 13

What is the definition of diffusion

Answer 13

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

Question 14

What is the definition of active transport

Answer 14

Transport of substances up the concentration gradient requiring energy and carriers e.g Na/K pump

Question 15

How many cell types are there

Answer 15

Approx 200 cell types

Question 16

What are some examples of these cell types

Answer 16

Stem cells, erythrocytes , leukocytes, platelets, neurons, neuroglial cells, myocytes and chrondrocytes

Question 17

What are the different types of cell actions

Answer 17

Reproduce, nourishment ( create and maintain), movement ( energy and transport) , excretion ( get rid of waste) , growth and respiration

Question 18

What are examples of cells in action

Answer 18

Red blood cells - carry oxygen
Kidney tubule cells - controls water & salt excretion
Cardiac cells - contract & control heart pumping
Cartilage- structural support
Neurone - conduct electrical impulses
Sperm - convey genetic material for reproduction

Question 19

What are the four different types of cellular tissue types

Answer 19

Connective tissue, epithelial tissue, muscle tissue and nervous tissue

Question 20

What is connective tissue

Answer 20

Lattice shape, most abundant type of cells - binding, supporting, protecting ( e.g. cartilage , blood, adipose, bone)

Question 21

What is epithelial tissue

Answer 21

Cells forming continuous sheets often lining body cavities ( e.g. skin, gut lining , glands )

Question 22

What is muscle tissue

Answer 22

Skeletal muscle under voluntary control, attached to bone for motion/ posture

Question 23

What is the two different types of muscle tissue

Answer 23

Smooth muscle and cardiac muscle

Question 24

What is smooth muscle

Answer 24

Forming walls of tubes e.g. airways, blood vessels, gut, bladder, uterus for propulsion of substances

Question 25

What is cardiac muscle

Answer 25

Under involuntary control causing the heart to pump

Question 26

What is nervous tissue

Answer 26

Neurones conduct electrical impulses throughout the body ( e.g. brain, spinal cord ) to control body function/ movement

Question 27

What is the order of organismal development

Answer 27

1) chemical level 2) cellular level 3) tissue level 4) organ level 5) system level 6) organismal level

Question 28

What is apoptosis

Answer 28

Cell suicide and helps to avoid continuous replication as well as important to allow new cells to grow

Question 29

What is necrosis

Answer 29

Cell damage/ disease

Question 30

What are some cells that continually replaced

Answer 30

Gut epithelium ( turnover every 3 days ) and skin epidermis ( turnover every 2-4 weeks)

Question 31

What are some cells that aren’t replaced

Answer 31

Muscle Nervous system (50% of cells will die by the time we are old)

Question 32

What occurs in aging

Answer 32

Mitosis lows down so cels that die aren’t replaced which causes signs of aging

Question 33

How does apoptosis affect aging

Answer 33

Can increase in some cells causing disease e.g. Alzheimer’s where valuable nerve cells die more quickly It can also stop which causes cells to ver divide causing tumors

Question 34

What is homeostasis

Answer 34

When conditions in the internal environment are maintained within physiological limits

Question 35

What occurs when homeostasis is disturbed

Answer 35

Illness may result, if body cells aren’t brought back death may occur

Question 36

What must be kept constant to protect the cell

Answer 36

Chemical constitutions Osmotic pressure Temperature O2/CO2 levels

Question 37

How does homeostasis work

Answer 37

Receptors Having a control system Effectors

Question 38

How is high body temperature controlled

Answer 38

Receptors = skin& hypothalamus receptors Control system= hypothalamus & pituitary glands Effector= sweating & skin capillary vasodilation Corrective response = heat loss

Question 39

How is low body temperature controlled

Answer 39

Receptors = skin & hypothalamus Control system = hypothalamus & pituitary gland Effector= skin hairs stand on end, skin capillary vasoconstriction, shivering Corrective response = heat gain

Question 40

What is negative feedback

Answer 40

If response reverses original stimulus ( goes back to normal levels)

Question 41

What is positive feedback

Answer 41

If response enhances original stimulus ( continues to reinforce the original stimulus)