year 7 science Flashcards
(151 cards)
1
Q
What are the components of a plant cell?
A
Ribosomes
Nucleus
Cell membrane
Cytoplasm
Mitochondria
Chloroplast
Cell wall
Vacuole
2
Q
What is the function of ribosomes?
A
Site of protein synthesis
2
Q
What are the components of an animal cell?
A
Ribosomes
Nucleus
Cell membrane
Cytoplasm
Mitochondria
2
Q
What is the function of the nucleus?
A
Stores genetic material (DNA)
Controls the cell and cellular function
3
Q
What is the function of the mitochondria?
A
Site of respiration
4
Q
What is the function of the cytoplasm?
A
Provides an aqueous environment for cellular reactions
5
Q
What is the function of the cell membrane?
A
Separates the intracellular and extracellular environments and provides a selectively permeable barrier for molecules to move in and out of the cell
6
Q
What is the function of the cell wall?
A
Provides strength, structure and stability to the plant cell
7
Q
What is the function of the chloroplasts?
A
Site of photosynthesis
8
Q
Where in the plant are chloroplasts found?
A
Green parts of the plant, mostly the leaves/ stem
9
Q
What is the function of the vacuole?
A
Maintains the water balance of the plant cell and provides turgor pressure to help maintain plant strength and shape
10
Q
What organelles are only found in plants?
A
Vacuole
Cell wall
Chloroplasts
11
Q
Components of the cardiovascular system?
A
Heart
Blood vessels; arteries, veins and capillaries
12
Q
What is the function of the cardiovascular system?
A
Maintains and adequate and effective blood supply around the body to ensure oxygenated blood reaches metabolically active tissue
13
Q
Components of the digestive system?
A
Pancreas, large intestine, small intestine, stomach, oesophagus, liver, mouth
14
Q
What is the function of the digestive system?
A
To digest ingested food and absorb sufficient nutrients and excrete indigestible material
15
Q
What are the components of the endocrine system?
A
Pituitary gland
Pancreas
Adrenal gland
Thyroid
Ovaries/ tetes
16
Q
What is the function of the endocrine system?
A
Involved in hormonal response and feedback to normal body function
17
Q
What are the components of the
musculoskeletal system?
A
The bones and muscles
18
Q
What is the function of the skeletal system?
A
To stand upright and be able to move. To also carry out voluntary movements.
19
Q
What is the function of the respiratory system
A
To allow ventilation and carry out gas exchange
20
Q
What are the components of the respiratory system?
A
Lungs
Respiratory muscles
Rib cage
Air way
21
Q
What is the function of the reproductive system
A
To produce viable gametes capable to produce offspring
22
Q
What is the function of the immune system?
A
To defend against illnesses and fight against infections
23
What are the components of the immune system?
lymph nodes
Bone marrow
Spleen
24
What is the function of the nervous system?
To co ordinate neural activity from sensory organs
To effector organs.
25
What are the components of the nervous system?
Peripheral nerves
Brain
Spinal cord
26
What is the function of a red blood cell?
It carries oxygenated blood from the lungs to metabolically active tissue.
27
What are the adaptations of a red blood cell?
It does not have a nucleus. Packed with haemoglobin. It has a very small diameter.
28
What is the function of a neuron?
It carries electrical impulses to co-ordinate neural activity.
29
What is the lifespan of a red blood cell?
120 days.
30
What is a control variable?
variable that does not change.
31
What is an independant variable?
a variable that can be changed or manipulated.
32
What is a dependant variable?
a variable that is being tested or measured.
33
Why do we need to breathe out?
To release carbon dioxide.
34
Why do we need to breathe in?
To take in oxygen.
35
What is the definition of precise?
How close the repeats are to each other.
36
What is the definition of accurate?
How close your results are to the correct value.
37
What is diffusion?
Movement of particles from a region of high concentration to a region of low concentration. This movement is down a concentration gradient.
38
What is osmosis?
The movement of water from a region of high concentration to a region of low concentration across a partially permeable membrane. Down a concentration gradient.
39
What is active transport?
Movement of particles to a lower region of particles to a higher concentration of particles. This against concentration gradient and requires energy from ATP.
40
What is the function of the bone marrow?
Produces blood cells
41
What are the features of a good exchange surface?
Good blood supply to maintain good diffusion gradient.
A short diffusion distance.
Large surface area.
Good ventilation to maintain diffusion gradient.
42
What is the function of a joint?
Generates movement in certain planes and directions to allow purposeful movement.
43
What are the different types of joints?
Hinge joints.
Fixed joints.
Ball and socket joints.
A pivot joint
44
What is a synovial joint?
When the two ends of the bones are encased in a membrane and has a circulating fluid in the joint space.
45
What is the function of synovial fluid?
Act as lubricant for the joint to aid movement and reduce friction. Also nourishes the joint.
46
What is a ligament?
A piece of tissue that holds two bones together.
47
What is a tendon?
A piece of tissue that connects muscle to a bone.
48
What is the fomular to calculate the total magnification?
Eyepiece lense ×objective lense
49
Why do we need the stain samples to view them under a microscope?
Because cell samples are colorless and by staining them, they are become visable
50
What is the main hormone responsible adolescence in females?
Oestrogen
51
What is the main hormone responsible adolescence in males?
Testosterone
52
What changes do females undergo during puberty?
Breasts develop
ovaries start to release egg cells
periods start
hips widen
pubic hair starts to grow
underarm hair
53
What changes do men undergo during Puberty in males?
voice breaks
testes and penis get bigger
testes start to produce sperm
shoulders widen
facial hair grows
54
What does universal indicator show:
a)How strongly acidic or alkaline a solution is?
b) Whether a solution is acidic or alkaline?
c) how much water a solution has?
B.) w
55
What range of value on universal indicator, indicate acidic solution?
0-7
56
What range of value on universal indicator, indicate alkaline solution?
7-14
57
What range of value on universal indicator, indicate neutral solution?
7
58
What condition is needed to measure the pH of a substance?
it must be dissolved in water
59
what is neutralisation?
It is when an acid and an alkaline react to form water
60
what is seen when red litmus paper is dipped in an acidic solution?
it stays red
61
what is seen when red litmus paper is dipped in an alkaline solution?
it turns blue
62
what is seen when blue litmus paper is dipped in an acidic solution?
it turns red
63
what is seen when blue litmus paper is dipped in an alkaline solution?
it stays blue
64
What is an acid?
it is a solution with a pH below 7, and all of their molecules can release hydrogen ions.
65
What are some examples of acids?
Hydrochloric acid, citric acid, carbonated drinks, vinegar
66
What is an alkali?
it is a base that dissolves in water and has a pH above 7
67
what are examples of alkalis?
soap, toothpaste, bleach, sodium hydroxide
68
What are the danger properties of acids?
They are corrosive, flamable, causes burns and can be a skin irritant
69
what are the useful purposes of neutralization?
Neutralisation of acidic soil, taking indigestion tablets for too much acid in the stomach, in lakes and ponds to neutralise water.
70
What is produced when an acid reacts with a metal?
it will produce salt and hydrogen.
71
What is produced an alkali/base reacts with an acid?
it produces salt and water
72
What is produced when an acid reacts with a carbonate?
salt, water and carbon dioxde
73
How long does it take for the earth to complete a full orbit around the sun?
365 days and 6 hours
74
Is the sun a star or a planet?
It is a star
75
What is the definition of a solar system?
a sun and all the objects that orbit it
76
what is the solar system?
a star and all the objects that orbit it
77
what are the components of the solar system?
Stars , galaxies, planets, moons, satalittes ,asteroids , comets, dust and gas
78
What planets make up our solar system?
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
79
what are terrestrial planets and examples of these?
planets that re made up of mostly rock and metal and have a solid surface and these are Mercury , Earth, Venus and Mars
80
which planet is the hottest planet in the solar system?
Venus
81
what is a gas giant planet and some examples?
it is a massive planet that is made up of hydrogen and helium gas ,they are also surrounded by rings and moons. Jupiter
Saturn, Uranus and Neptune.
82
What is an Asteroid?
They are large piece of rock that orbit the sun.
83
Where is the Asteroid belt found?
It is found between mars and Jupiter
84
What is a dwarf planet?
They are planets that are too small to be considered to be a planet
85
How many dwarf planets are there in our solar system?
There are 5
86
What is a comet?
They are things in the solar system that are made up of rock and ice
87
What is an orbit?
an orbit is a path followed by an object in space?
88
How long is one day?
24 hours
89
What happens in one day?
The earth complete one rotation on its' axis
90
what happens when we experience day time?
The earth's face is pointing towards the sun
91
what happens when we experience nightime?
The earth is facing away from the sun
92
what happens in the time of a year?
the earth completes one full orbit around the sun.
93
Why do we have seasons?
Because the earth is tillted on an axis
94
What is the size of the Earths' tilt?
23 degrees
95
What are the four seasons?
spring, summer, autumn and winter
96
What is a month?
It is the time it takes for the moon to orbit the Earth once, 29.5 calendar days
97
What is a force?
it is a push or pull acting on an object due to its interaction in another object.
98
what is the unit of a force ?
it is measured in Newtons
99
what are examples of contact forces?
Friction, tension, air-resitance , up-trust
normal reaction force.
100
what are examples of non-contact forces?
magnetic force, electrostatic force and gravitational force
101
what is tension?
it is a pulling force exerted by an object,
by a string.
102
what is friction?
when two objects slide past eachother, they exert frictional force.
103
what is up-trust?
An upward force an object experiences when submerged in a fluid.
104
what is air-resistance?
it is the force and object experiences as it moves through air.
105
what is a normal reaction force?
The forces acting between an object and a surface.
106
what is a magnetic force?
the forces experienced by a magnetic material when placed in a magnetic field.
107
what is an electrostatic force?
it is the force experienced by a charge particle in an electric field.
108
what is a gravitational force?
a force experienced by an object with mass when it is suficiently close to another object with mass
109
what effect can a force have on an object?
it can change the speed of a moving object, change the direction and change the shape.
110
what is Hooke's law?
when the force applied to an elastic object is directly proportional to the extention, provided the limit of proportion is not exceeded.
111
What is the difference between a transparent and translucent material?
when a material is translucent- allows light to pass through but causes it to diffuse.
when a material is transparent - it allows objects to transmit light fully
112
What is the law of reflection?
it is when the angle of incidence is equal to the angle of reflection
113
what is a light year?
The distance traveled by light in the space of one year
114
what is specular reflection?
when light is reflected from a smooth surface
115
what is diffuse scattering?
when light is reflected off a rough surface
116
what does a lens do to light?
refracts the light wave as it passes through causing it to change direction and speed
117
List the planets in the solar system, in size order starting with the smallest to the biggest
Mercury
Mars
Venus
Earth
Neptune
Uranus
Saturn
Jupiter
118
What is the evidence for the Earth spinning on it's axis?
Because we have day and night
119
what are the phases of the moon?
new moon
cresent
first quarter
gibbous
full moon
gibbous
third quarter
cresent
120
What is the function of a stop clock?
A device used to measure the time taken
121
What is the function of a measuring cylinder?
To measure the volume of a liquid
122
What is the function of a weighing scale?
To measure the mass of a substance
123
What is the difference of a test tube and a boiling tube?
A boiling tube is wider and bigger than a test tube
124
What is a gas syringe used for?
it is used to measure the volume of a gas produced in a reaction
125
What is an atom?
It is the smallest component that can take part in a chemical reaction
126
What are the components of an atom?
Proton, neutron and electron
127
What is the charge on a proton?
it is positive
128
what is the charge on an electron?
it is negative
129
what is the charge on a neutron?
it is neutral
130
what components of an atom are found in the nucleus?
protons and neutrons
131
What is an element?
it is a chemical substance made of only one type of atom
132
What is a compound?
it is a chemical substance made up of two or more different elements that are chemically bonded together
133
what is the periodic table?
it is an internationally recognised organisation of elements
134
what are the two types of waves?
longitudinal and transverse
135
what are three properties of a wave?
amplitude, frequency and wavelength
136
What is the definition of amplitude?
it is the furthest displacement of the wave from the mean position
137
what is the frequency of a wave?
it is the number of oscillations per unit time
138
what is the wavelength?
it is the distance between two identical points on two consecutive waves
139
what property of waves determines volume of sound?
it is the amplitude
140
what property of waves determines the pitch of sound?
it is the frequency
141
what type of wave is sound?
longitudinal
142
what is the definition of a transverse wave?
it is a wave with oscillations perpendicular to the direction of energy transfer
143
what is the definition of a longitudinal wave?
it is a wave with oscillations parallel to the direction of energy transfer
144
what are examples of chemical alkalis?
ammonia, sodium hydroxide, potassium hydroxide, calcium hydroxide
145
What is a group on a periodic table?
is is the vertical column which corresponds to the number of electrons of the outer shells of the element
146
what is a period on the periodic table?
it is the horizontal rows which corresponds to the number electron shells in the atom
147
what is the property of all group 8 elements?
they are inert and do not react
148
What is the boiling point of water?
it is 100 degrees celcius
149
what is the melting point of water?
0 degrees celcius
