Biology (Cells) End of Year Exam Grade 9

Question 1

Types of cells

Answer 1

Animalia, Fungi, Eubacteria, Plantea, Protists, Archaebacteria.

Question 2

All organisms are…

Answer 2

are composed of either prokaryotic or eukaryotic cells.

Question 3

Prokaryotes

Answer 3

No nucleus
DNA is naked
Unicellular
Smaller (1-5 micrometers)

Question 4

Eukaryotes

Answer 4

Has nucleus
DNA is bound to protein
(DNA is wrapped around histone proteins. This helps organize the massive amount of DNA packed within each chromosome.)
Unicellular and multicellular
Larger(10-100 micrometers)

Question 5

Both prokaryotes and eukaryotes

Answer 5

DNA
Cell membrane
Ribosomes (make protein)

Question 6

Antibiotics

Answer 6

Medicine used against bad bacterial infections.

Question 7

Probiotics

Answer 7

Promote good bacteria in your body.

Question 8

Levels of organization

Answer 8

Cells - Tissues - Organs - Organ System - Organisms

Question 9

Nerve cells

Answer 9

They use electrical and chemical signals to send information between different areas of the brain, as well as the spinal chord and the entire body.

Question 10

Stem cells

Answer 10

Unspecialized unique cells of the body that have the ability to develop into several different types of cells.

Question 11

Types of stem cells

Answer 11

Embryonic stem cells
Cord blood stem cells
Adult stem cells

Question 12

Embryonic stem cells

Answer 12

+ can differentiate into any type in body (pluripotent)
- destruction of potential living things
- more risk of developing into tumor

Question 13

Cord blood stem cells

Answer 13

+ no ethical problem
+ easy to obtain and store
- limited capacity to differentiate

Question 14

Adult stem cells

Answer 14

+ you receive consent
+ removal does not kill adult
+ less chance of malignant tumor
- limited differentiation (multipotent)
- difficult to obtain

Question 15

Example of stem cell therapy

Answer 15

Stargardt’s disease. - causes vision loss
Parkinsons disease - degenerative disorder

Question 16

Substances that need to move in and out of cells

Answer 16

Iron, oxygen, carbon dioxide, glucose and protein.

Question 17

Types of passive transport

Answer 17

Diffusion and osmosis
*no energy is required for passive transport

Question 18

Diffusion

Answer 18

Randomized movement
High - low concentration

Question 19

Osmosis

Answer 19

Movement of water molecules
Influenced by concentration of solute

Question 20

Cell membrane

Answer 20

Semi-permeable: lets certain things in and keeps other things out.

Question 21

Types of solutions

Answer 21

Hypertonic, hypotonic, and isotonic

Question 22

Hypertonic

Answer 22

water will move out (the cell becomes dehydrated and shrinks)
*moves out to try to balance the amount of H20

Question 23

Hypotonic

Answer 23

water will move in (the cell will expand and possibly burst)
*Moves in to try and balance the H20 to the solute

Question 24

Isotonic

Answer 24

water will move in and out - equal movement (cell/tissue stay the same)

Question 25

Osmolarity

Answer 25

concentration of solute

Question 26

Organ transplants

Answer 26

Osmosis in real life To transport organs you need to transport in isotonic solution so it does not shrink or swell.

Question 27

IV solutions

Answer 27

You are hooked up to IV to keep the person hydrated. There is salt in the solution so it is a isotonic solution not a hypotonic solution.

Question 28

Cellular respiration

Answer 28

A series of reactions/processes that take place in cells or organisms to convert chemical energy in oxygen and nutrients to (ATP) energy C6H12O6 + 6O2 - 6CO2 + 6H2O + ATP Glucose + Oxygen - Carbon dioxide + water + energy

Question 29

ATP

Answer 29

is a high energy molecule that functions as an immediate source of energy cells

Question 30

Some processes that need (ATP) energy

Answer 30

Movement Active transport Growth (cell division) For your neurons to send signals Digestion

Question 31

Aerobic respiration

Answer 31

Happens in mitochondria to yield large amount of ATP. *oxygen is needed *much of the process occurs in the mitochondria (powerhouses of the cell)

Question 32

Anaerobic respiration

Answer 32

Happens outside the mitochondria in the cytosol and yields small amounts of ATP when no oxygen is present. *Animals: Glucose (reactant) - Lactid acid (product) + small amount of ATP *Plants and yeast: Glucose - Ethanol +Carbon dioxide + energy (ATP)

Question 33

Differences between Anaerobic and Aerobic respiration

Answer 33

Generates less amount of ATP in anaerobic and more aerobic Occurs in different places in the cell Oxygen is needed in one and not the other.

Question 34

Example of fermentation

Answer 34

Bread goes through alcoholic fermentation which contributes to the production of ethanol. In bread, yeast and bacteria convert sugars into carbon dioxide, causing the dough to rise.

Question 35

Functions of life

Answer 35

Reproduction - living things produce offspring, either sexually or asexually Excretion Nutrition Homeostasis Metabolism Sensitivity Growth

Question 36

Endosymbiotic theory

Answer 36

Ancestral prokaryotes - infolding of plasma membrane - endosymbiosis *Ancestral eukaryote (how eukaryotic cells formed) Smaller prokaryotes were engulfed by larger prokaryotes uniting to become more complex

Question 37

Viruses

Answer 37

can reproduce only by infecting living cells Not considered to be living (a non living particle) Have DNA or RNA

Question 38

Cycle of a virus

Answer 38

(Lytic infection) Viral genes are transcribed by the host cell The bacterium makes new viral proteins and nucleic acid The proteins and nucleic acid assemble into new viruses New viruses escape and infest other cells.

Question 39

Examples of viral infections

Answer 39

Covid 19 Pneumonia

Question 40

Microscopes

Answer 40

Light microscope - light is used Electron microscope - higher magnification and more expensive

Question 41

M = Magnification

Answer 41

M = size of image (I)/actual size of specimen (A)