year 9 science exam revision

Question 1

The Scientific Method

Answer 1

1. Research Question
2. Research
3. Hypothesis
4. Experiment (create experiment)
5. Discussion (analyse results)
6. Conclusion (state whether hypothesis is supported or not)

Question 2

Independent Variable

Answer 2

The variable that is changed to affect the dependent variable.

Question 3

Dependent Variable

Answer 3

The Variable that is being measured and tested.

Question 4

Validity

Answer 4

How the Data truly represents and relates to claims and the investigation.

Question 5

Accuracy

Answer 5

The closeness of a measured value to a value

Question 6

Precision

Answer 6

The closeness between 2 measurements

Question 7

Replication

Answer 7

The duplication of experiments so that it can be run more than once at the same time

Question 8

Reliability

Answer 8

How reliable and experiment is. Reliability can be increased through replication.

Question 9

Control

Answer 9

Something that is kept the same

Question 10

Systematic Error

Answer 10

Systematic errors are errors caused by an inaccuracy in the observation or the measurement process which is due to the system.

Question 11

Gross error

Answer 11

a human error or a random error that. cannot be prevented

Question 12

Autotrophs (producers)

Answer 12

Autotrophs produce food sources. They are essential in every ecosystem.

Question 13

Heterotrophs (consumers)

Answer 13

Require a ready made source of food

Question 14

Decomposers

Answer 14

Breaks down dead bodies and waste for producers.

Question 15

Carrion

Answer 15

Dead or rotten flesh.

Question 16

Detritus

Answer 16

Waste products.

Question 17

Photosynthesis

Answer 17

6CO2 + 6H20 = C6H12O6 + 6O2

Question 18

Cellular respiration(aerobic)

Answer 18

C6H12O6 + 6H2O = 6CO2 + 6H2O + (36-38) ATP

Question 19

Cellular respiration(anaerobic)

Answer 19

C6H12O6 = 2C3H6O3 + (2) ATP

Question 20

Homeostasis

Answer 20

Where the body is able to maintain an equal and stable internal environment.

Question 21

Endocrine System

Answer 21

A Communication system that controls the internal environment of the body. It controls=
Hormones
Glands

Question 22

Hormones

Answer 22

Hormones are chemical substances that act as messages. Travels through blood.

Question 23

Abiotic

Answer 23

non-living factors of an ecosystem environment

Question 24

Biotic

Answer 24

Living factors include dead organisms and their wastes

Question 25

Ectothermic

Answer 25

coldblooded

Question 26

Endothermic

Answer 26

birds and mammals

Question 27

Energy in ecosystems

Answer 27

producer 100% e –> 1st consumer 10 % —> 2nd consumer 1% –> 0.1% 3rd consumer tertiary.
energy is lost inorder to grow, metabolism and for heat. Which is why a 3rd order consumer has to eat a lot.

Question 28

Neurotransmitters

Answer 28

The chemicals that are released during synapses which carry messages.

Question 29

Neurons

Answer 29

• Are nerve cells that transmit electrical messages from the body. Electrical impulses are called nerve impulses, they go 1 direction.

Question 30

Motor neurons

Answer 30

carry messages from CNS to effectors.

Question 31

Sensory Neurons

Answer 31

Have specialised receptors for senses

Question 32

Dendrites

Answer 32

Receive information

Question 33

Axon terminals

Answer 33

can connect to a muscle or a sensory receptor. sends info.

Question 34

Atidiactic hormone (ADH)

Answer 34

controls water levels

Question 35

Pancreas gland

Answer 35

produces insulin+glucose, controls glucose levels.

Question 36

Adrenal gland

Answer 36

Adrenaline. Flight or fight response.

Question 37

Ovaries (female)

Answer 37

controls female sexual gland and menstrual gland

Question 38

Progesterone

Answer 38

controls ovaries during pregnancy

Question 39

testes

Answer 39

produces testosterone.

Question 40

Thyroid

Answer 40

produces thyroxin which controls the rate of chemical reactions in a cell.

Question 41

Cerebellum

Answer 41

Small lump at the back. Responsible for coordination and balance.

Question 42

Right Cerebrum

Answer 42

Visual processing and creative side. Left hand

Question 43

Left Cerebrum

Answer 43

Logical and mathematical thinking. Right hand.

Question 44

Spinal Cord

Answer 44

Acts as a reflex centre for nerves. Caries information to the rest of the body.

Question 45

The medulla

Answer 45

contains our vitals.

Question 46

Brainstem

Answer 46

controls message transfers.

Question 47

Isotopes

Answer 47

Isotopes of an Element share the same number of protons but a different number of neutrons.

Question 48

Radiation

Answer 48

the emission of energy as electromagnetic waves or as moving subatomic particles

Question 49

Radioactivity

Answer 49

emmission of particles and electromagnetic radiation.

Question 50

Covalent bonding

Answer 50

Non-metal + Non-metal.
single molecules that share electrons between 2 or more non-metals. Can sometimes make a lattice (diamond) but mostly small compounds and molecules. Low MP + BP

Question 51

Metallic bonding

Answer 51

Metal + Metal.
Arranged in a lattice. the electrons become delocalised which means they are free to roam around the metal atoms. The delocalised atoms are held together. by electrostatic attraction. High MP

Question 52

Ionic Compounds

Answer 52

Metal + Non-metal.
metal is cation, donates electrons. non-metal is anion.
Ionic lattice is made of alternating cations and anions.
High MP. When solid cant conduct electricity. When dissolved in water or liquid yes.