Units 1 & 2 Biology Revision

Front 1

Placing organisms in groups

Back 1

Kingdom -> phyla -> class -> order -> family -> genus -> species

Front 2

Endoplasmic Reticulum (ER)

Back 2

- transports substances around the cell

- inter-connected system of membrane-closed flattened channels

-ER with ribosomes is ROUGH ER

- NO ribosomes is SMOOTH ER

Front 3

DEFINE ecosystem

Back 3

Biological unit comprising of the community living in a discrete region

Front 4

Keystone species

Back 4

species that have a large role in the ecosystem

Front 5

Competition

Back 5

INTERSPECIFIC: competition for resources in an ecosystem involving 2 species

INTRASPECIFIC: competition for resources in an ecosystem involving some species

Front 6

Taxonomy

Back 6

identifying, naming, describing and classifying organisms into groups

Front 7

Biodiversity

Back 7

Total number of DIFFERENT organisms living in an area

Front 8

Lysosomes

Back 8

- a sack containing about 50 digestive enzymes which break down bacteria

- performs autophagy - breaks down non-functioning cells

Front 9

3 levels of biodiversity

Back 9

1. species diversity

2. genetic diversity

3. ecosystem diversity

Front 10

Chloroplasts

Back 10

- found in plant and algae cells

- responsible for performing photosynthesis

- has 2 membranes

Front 11

Nucleus

Back 11

- in eukaryotic cells

- membrane bound organelle containing DNA
- has a double membrane, called nucleus envelope

Front 12

Xylem

Back 12

transports inorganic substances (water & dissolved ions) from roots to leaves

Front 13

Active transport

Back 13

- Goes against concentration gradient

- Moves substances from area of low concentration to an area of high concentration

- ENERGY NEEDED (normally ATP)

Front 14

Pholem

Back 14

- transports organic substances produced by photosynthesis (glucose) from leaves to rest of plant

Front 15

Facilitated diffusion

Back 15

- uses special protein transporters (channel/carrier proteins) in plasma membrane

- NO ENERGY required

- channel proteins: tunnel (pore) that creates hydrophilic passage, diffuses charged particles

- carrier proteins: allows diffusion of 1 kind of molecule

Front 16

Osmosis

Back 16

- movement of water from area of high water to area of low water through semi-permeable membrane

Front 17

High water levels

Back 17

S - increased water levels

R- osmoreceptors

C- Hypothalamus (stops ADH release)

E- Kidney tubules

R- Decreased reabsorption of water, increased urine volume

Front 18

Low water levels

Back 18

S- decrease in water level

R - osmoreceptors

C - Hypothalamus (1. release of ADH 2. thirst centre)

E - Kidney tubules, thirst behaviour

R - Increased reabsorption of water, decreased urine volume

Front 19

Positive feedback

Back 19

Keep doing the same thing that was already happening

Front 20

Negative feedback

Back 20

System detects change and acts to reverse change

Front 21

Decrease of core temp

Back 21

S - Decrease in temp

R - Thermoreceptors detect change

C - hypothalamus

E - muscles, blood vessels, body cells

R - shivering, vasoconstriction, increase metabolic rate

Front 22

Peroxisomes

Back 22

-Rich in the enzymes that detoxify various toxic materials that enter bloodstream

- Responsible for oxidation of fatty acids

Front 23

Mitochondria

Back 23

- in eukaryotic cells only

- Produces adenosine triphosphate (ATP)

- produces ATP through cellular respiration

Front 24

Insulin

Back 24

- made by Beta cells

- transport of glucose into some body cells

- Insulin decreases glucose in blood

Front 25

Low level of glucose

Back 25

S - decrease in blood glucose

R - alpha cells of pancreas

C - Alpha cells secrete glucagon

E - Liver cells

R - Liver cells release glycogen (glucose)

Front 26

Glucagon

Back 26

- made by alpha cells

- makes liver release stored glycogen

- glucagon increases glucose in blood

Front 27

G.A.B.I

Back 27

Glucagon released by Alpha cells

Beta cells release Insulin

Front 28

High glucose levels

Back 28

S - increased blood glucose

R - beta cells in pancreas

C - beta cells release insulin

E - Liver cells

R - uptake of glucose (by liver)

Front 29

Respiration (continued...)

Back 29

- ADP + P = ATP

- occurs in mitochondria & cytosol (95% ATP made in mitochondria)

- Glucose needed for ADP to turn into ATP

Front 30

Prokaryotic cells

Back 30

- lack membrane bound nucleus & organelles

- E.G. bacteria (unicellular)

- Circular DNA

Front 31

Cell organisation

Back 31

1. Cell

2. Tissue

3. Organ

4. Organ system

Front 32

Heterotrophs

Autotrophs

Chemotrophs

Back 32

Heterotrophs: obtain energy through consumption of other organisms (omnivores)

Autotrophs: synthesise energy or glucose using sunlight

Chemotrophs: Generate energy from inorganic substances E.G. ammonia, live in places with no light

Front 33

Ribosomes

Back 33

- where proteins are made

- Contains RNA

Front 34

Stimulus response model

Back 34

Stimulus

Receptor

Control centre

Effector

Response

Front 35

Homeostasis

Back 35

-maintaining a level of balance for certain physiological variables (temp, glucose, water, urea)

- MAIN SYSTEM: ENDOCRINE SYSTEM

Front 36

Biomimicry

Back 36

- practice of learning from & being inspired by nature to achieve technological advances

Front 37

Tolerance range

Back 37

Particular environmental conditions in which an organism can survive

Front 38

Behavioural adaptations

Back 38

Activities organism does to help survive

Front 39

Increase of core temp

Back 39

S - hypothalamus detects increase

R - thermoreceptors

C - message sent to hypothalamus

E - Sweat glands, blood vessels, body cells

R - Sweat, vasodialate, decreased metabolic rate

Front 40

Hypertonic

Hypotonic

Isotonic

Back 40

Hypertonic: having a higher solute concentration than cells content (less water outside cell)

Isotonic: having equal solute concentration to that of cell

Hypotonic: having a lower solute concentration than cells content (more water outside cell)

Front 41

Eukaryotic cell

Back 41

- have membrane bound organelles

E.G. animals, plants, fungi

- linear DNA

Front 42

Cell wall

Back 42

- found only in plant cells

- Allows things to pass through

Front 43

Golgi complex

Back 43

- responsible for export of substances out of cell

- multi-layered structure, made of stacks of membrane line channels

Front 44

Adaptations

Back 44

Genetically controlled feature that enhances survival

Front 45

Structural adaptation

Back 45

Anatomical parts of the body (external) to assist survival

Front 46

Physiological adaptation

Back 46

Internal responses made by the systems to assist survival

Front 47

Growth rate equation

Back 47

Growth rate = (Birth + immigration) - (deaths + emigration)

Front 48

Respiration

Back 48

- Transfer of energy from glucose to ATP

glucose + oxygen -> carbon dioxide + water

Front 49

Aerobic respiration

Back 49

oxygen needed

34 ATP's made

Slow process

Front 50

Anaerobic respiration

Back 50

no oxygen needed

2 ATP's made

quick process

by product of lactic acid = fatigue, muscle soreness

Front 51

Simple diffusion

Back 51

- movement of substances from area of high concentration to area of low concentration

- gases & uncharged molecules

-NO ENERGY is required

Front 52

Hypothyroidism & Hyperthyroidism

Back 52

Hypothyroidism: under-active thyroid gland that fails to secrete enough hormones

Hyperthyroidism: over-active thyroid gland that produces excessive amounts of thyroxine

Front 53

Useful forms of energy

Back 53

- ATP

- Glucose

- Glycogen

- Starch

- Fats

Front 54

Photosynthesis

Back 54

Carbon dioxide + water -> glucose + oxygen

- plants (occurs in chlorophyll found in chloroplasts)

Front 55

Hyperthermia & hypothermia

Back 55

Hyperthermia: elevated core temp due to failure of thermoregulation

Hypothermia: condition where somebody has abnormally low core temp

Front 56

Type 1 & Type 2 diabetes

Back 56

Type 1: beta cells of the pancreas produce little to no insulin

Type 2: insulin produced but the body cells do not respond (A.K.A insulin resistant)

Front 57

Amensalism

Back 57

One organism inhibits or destroys another organism

The organism that destroys the other gains no direct benefit

Front 58

Population distribution

Back 58

- refers to spread of members of a population over given area

A - uniform

B - random

C - clumped

Front 59

Commensalism

Back 59

One member gains, while nothing happens to the other (not harmed nor gains anything)

Front 60

Cytoplasm

Back 60

- clear, thick, jelly like material

- protects cell organelles

Front 61

Mutualism

Back 61

Both organisms benefit somehow

Front 62

Parasitism

Back 62

- Parasite lives in or on host but does not kill host

- Parasite benefits (feeds off host)

Front 63

Predator - prey relationship

Back 63

one species kills or eats another

Front 64

breakdown of ecosystem

Back 64

Cell -> organisation -> population -> community -> ecosystem

Front 65

Asexual reproduction

Back 65

one parental organism gives rise to 2 identical offspring

EXAMPLES: binary fission (bacteria) and budding

Front 66

Biological advantages of asexual reproduction

Back 66

- parent can produce without a mate

- offspring produced at a faster rate

- not a lot of energy required

Front 67

Biological disadvantages of asexual reproduction

Back 67

- little variation in the population

- rapid population growth that could lead to competition for resources

- any mutation in parents DNA will be passed of to offspring

Front 68

Clones

Back 68

asexually reproduced organisms with identical genetic makeup

Front 69

Gametes

Back 69

cells that contain half the number of chromosomes of somatic cells

Front 70

How are gametes formed?

Back 70

Through the process of Meiosis where genetic material is shuffled between homologous chromosomes

Front 71

Meiosis

Back 71

process of cell division that produces daughter cells, each of which have half the number of chromosomes of the original parent cell

- there a 2 nuclear divisions in meiosis

Front 72

Prophase I

Back 72

appearance of chromosomes, crossing over between non-sister chromatids of homologous chromosomes may occur

Front 73

Metaphase I

Back 73

Homologous chromosomes line up independently at the spindle equator

Front 74

Anaphase I

Back 74

Homologous chromosomes separate and move towards opposite poles

Front 75

Telophase I

Back 75

Chromosomes disappear, nuclear membrane forms and cell divides into 2 (each cell has half the number of chromosomes as the parent)

Front 76

Prophase II

Back 76

chromosomes reappear in each cell

Front 77

Metaphase II

Back 77

each chromosome lines up at the spindle equator

Front 78

Anaphase II

Back 78

Centromeres are split and sister chromatids move to opposite poles

Front 79

Telophase II

Back 79

Chromosomes disappear, the nuclear membrane reforms and each cell divides into 2

Front 80

Final product of meiosis

Back 80

four daughter cells

variation can exist between four cells as a result from crossing over and independent assortment during meiosis 1

Front 81

Non-disjunction

Back 81

when chromosomes fail to separate correctly during anaphase I or anaphase II

- gametes produced may have an extra copy of a chromosome or missing a chromosome

Front 82

Biological advantages of sexual reproduction

Back 82

genetically varied offspring

individual characteristics may aid in survival if environment changes