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Structures and functions of living organisms Flashcards

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1
Q

Define Tissue

A

A group of cells working together to carry out a specific function

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2
Q

Define Organ

A

A group of tissues working together to carry out a specific function

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3
Q

Define organ system

A

A group of organs working together to carry out a specific function

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4
Q

How is the labour divided within a cell?

A

Its divided within the organelles

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5
Q

5 parts of an animal cell

A

-Nucleus
-Mitochondria
-Ribosomes
-Cell membrane
-Cytoplasm

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6
Q

8 parts of a plant cell

A

-Nucleus
-Mitochondria
-Ribosomes
-Cell membrane
-Cytoplasm
-Permanent vacuole
-Chloroplasts
-Cell wall

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7
Q

2 functions of the nucleus

A

-Controls the cell
-Contains genetic material (in the form of chromosomes).

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8
Q

What is the function of the cytoplasm?

A

it is where most of the cell’s reactions take place

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9
Q

State the function of mitochondria

A

They are the site of aerobic respiration

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10
Q

State the function of ribosomes

A

They are the site of protein synthesis

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11
Q

What is the function of the cell wall and what is it made of?

A

It provides strength and support. It is made of cellulose

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12
Q

What is the function of the permanent vacuole and what does it contain?

A

It supports the cell and contains cell sap (a solution of sugars and salts).

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13
Q

What is the function of chloroplasts?

A

They are the site of photosynthesis

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14
Q

What is the function of the cell membrane?

A

-Controls what enters and leaves the cell
-Separates the cell from its environment

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15
Q

What is differentiation

A

The process by which cells become specialised

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16
Q

What are stem cells?

A

Stem cells are unspecialised cells that can differentiate into lots of different types of cells

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17
Q

3 advantages of using stem cells in medicine

A

-Stem cells can be used to treat paralysis
-Stem cells have the possibility t cure degenerative diseases like Parkinson’s
-Whole new tissues or organs can be grown that can be used to test drugs on

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18
Q
A
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19
Q

What chemical elements are present in carbohydrates

A

Carbon, Hydrogen and oxygen

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20
Q

What chemical elements are in lipids

A

Carbon, hydrogen and oxygen

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21
Q

What chemical elements are present in proteins

A

Carbon, Hydrogen, Oxygen, Nitrogen (Sulfur)

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22
Q

What complex carbohydrates like starch and glycogen made up of

A

Simple sugars

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23
Q

What are proteins made up of

A

Amino acids

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24
Q

What two molecules are lipids made of

A

glycerol and fatty acids

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25
Q

Define enzyme

A

Biological catalysts that increase the rate of metabolic reactions

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26
Q

State 4 factors that affect enzyme function

A

-Temp
-pH
-Substrate concentration
-Enzyme concentration

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27
Q

Describe the effect of temp on the rate of an enzyme-controlled reaction

A

-As temperature increases, so does the RoR
-Once the temp exceeds the optimum, the enzyme denatures and the RoR decreases

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28
Q

Why does the rate of an enzyme-controlled reaction increase when the temp increases

A

-As the temperature increases the particles have more kinetic energy
-This increases the chance of collisions between molecules

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29
Q

If the temp increases above the optimum, how does this affect enzyme function?

A

The active site will be distorted as the enzyme denatures to fit the substrate

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30
Q

Describe the effect of pH of an enzyme-controlled reaction

A

-RoR at the optimum pH
-If it’s too high or low, the enzyme works less efficiently and the active site may denature

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31
Q

Define diffusion

A

Net movement of molecules from an area of high concentration to an area of low concentration

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32
Q

How does temp affect the rate of diffusion

A

As temp increases, so does the rate of difussion as the particles have more kinetic energy and move faster.

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33
Q

Define osmosis

A

The net movement of water molecules from a high water potential to low water potential across a partially permeable membrane.

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34
Q

Define active transport

A

The movement of molecules from a low concentration to a high concentration against the concentration gradient using energy

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35
Q

Define photosynthesis

A

The process where some organisms are able to turn light energy into chemical energy.

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36
Q

What type of organisms use photosynthesis to make their own food?

A

Producers

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37
Q

Is photosynthesis endothermic or exothermic.

A

Endothermic

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38
Q

Where does photosynthesis take place?

A

In the chloroplasts.

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39
Q

Equation for photosynthesis.

A

Carbon dioxide+water→glucose+oxygen

6CO2+6H2O→C6H12O6+6O2

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40
Q

Describe the effect of temperature on the Rate of photosynthesis

A

-As temp increases, so does the rate of photosynthesis
-Once the temp exceeds the optimum, the rato of photosynthesis decreases as enzymes begin to denature.

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41
Q

Explain the effect of light intensity on the rate of photosynthesis.

A

As the light intensity increases, so does the rate of photosynthesis.

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42
Q

Explain the effect of carbon dioxide concentration on the rate of photosynthesis.

A

As the concentration of carbon dioxide increases, so does the rate of photosynthesis.

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43
Q

Define limiting factor.

A

A factor that limits the rate of reaction when there is not enough of it

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44
Q

What is the inverse square law?

A

As the distance from the light source doubles, the light intensity quarters

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45
Q

Describe the structure of leaf tissue from top to bottom.

A

-Upper epidermis
-Palisade mesophyll
-Spongy mesophyll
-Lower epidermis
+Guard cells

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46
Q

3 ways leaves are adapted for photosynthesis.

A

-Thin, which provides a short diffusion distance
-Spongy mesophll has lots of air spaces for efficient gas exchange
-Palisade mesophyll cells has lots of chloroplasts

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47
Q

What are magnesium an nitrate ions used for in organisms?

A

Magnesium=chlorophyll
Nitrate=amino accids

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48
Q

Why is a balanced diet important?

A

The body needs different substances in different proportions to function properly.

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49
Q

7 groups for a balanced diet

A

Carbohydrates, proteins, lipids (fats), vitamins, minerals, water and fibre

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50
Q

Function of carbohydrates in the diet

A

Main source of energy

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51
Q

What are the functions of proteins in the body?

A

Structural or metabolic roles and are used as hormones, enzymes, antibodies, etc…

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52
Q

Functions of lipids in the body.

A

-Energy storage
-Cell membranes
-Buoyancy
-Insulation

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53
Q

What is Vitamin A used for?

A

-Keeping the skin healthy
-Improved vision in the dark
-Strengthening the immune system

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54
Q

Function of vitamin C

A

Growth and repair

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55
Q

Function of vitamin D

A

Absorption of calcium

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56
Q

Function of calcium

A

Strengthens bones and teeth

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57
Q

Function of iron in the body

A

in haemoglobin to transport oxygen in blood

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58
Q

Function of water

A

-Reaction medium
-Temp control
-Transport

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59
Q

Function of fibre

A

Helps keeping everything flowing through the digestive system.

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60
Q

Describe the passage through the ALIMENTARY canal

A

Mouth→Oesophagus→Stomach→Small intestine→Large intestine→rectum

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61
Q

Compare the energy requirements of a more and a less active person

A

More active a person is, the greater their energy requirement.
Adults require more energy than children

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62
Q

What is the difference between the alimentary canal and the digestive system?

A

The alimentary canal involves the tubes that the food passes through whereas the digestive system also includes digestive glands.

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63
Q

Function of the mouth

A

-Chew and break down food
-Secrete amylase enzymes

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64
Q

What’s the oesophagus?

A

Tube that carries food from the mouth to the stomach

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65
Q

Function of the stomach

A

Muscular sac containing acid that pummels the food and breaks it down further

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66
Q

Role of the pancreas in digestion

A

Secretes protease, amylase and lipase into the small intestine.

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67
Q

What are the two parts of the intestine called?

A

Duodenum and ileum

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68
Q

Function of the duodenum and ileum

A

duodenum=uses enzymes and chemical digestion to break the food down
ileum=most nutrients are absorbed from the food in the ileum into the blood.

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69
Q

How are villi (in the small intestine), adapted for absorption.

A

-Thin walls
-Good blood supply close to surface
-Large surface area (villi have microvilli).

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70
Q

Function of the large intestine

A

Water is absorbed into the blood.

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71
Q

Function of the rectum

A

Stores faeces before egestion

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72
Q

How does peristalsis work?

A

Muscles contract in a wave like pattern which cleates a bolus.

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73
Q

What enzymes break down to glucose

A

Starch(Amylase)Maltose
Maltose(Maltase)Glucose

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74
Q

What enzymes breaks proteins down into amino acids

A

Proteases

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75
Q

What group of enzymes breaks lipids into glycerol and fatty acids?

A

Lipases

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76
Q

Function of bile

A

-Neutralises the stomach acid and provides alkaline conditions for the digestive enzymes in the small intestine
-Emulsifies (breaks down into tiny droplets), fats

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77
Q

Where is bile produced and then stored?

A

Produced in the liver and stored in the gallbladder.

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78
Q

What’s the purpose of respiration?

A

To produce energy in the form of ATP from larger molecules

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79
Q

What is ATP

A

the source of energy for use and storage at the cellular level.

80
Q

Is respiration exothermic or endothermic?

A

exothermic

81
Q

When does anaerobic resporation take place in animals?

A

When there is no oxygen available.

82
Q

Symbol equation for aerobic respiration in animals

A

C6H12O6 +6O2→ 6CO2 + 6H2O

83
Q

What does anaerobic respiration in animals produce?

A

Lactic acid and energy

84
Q

What type of respiration produces more ATP?

A

Aerobic=36
Anaerobic=2

85
Q

What is the oxygen debt?

A

The extra oxygen that is needed to break down the lactic acid formed in anaerobic respiration.

86
Q

3 adaptations of leaf tissue for gas exchange

A

-Stomata allow diffusion of gases in and out of the plant
-Thin to shorten the diffusion distance
-Air spaces in the spongy mesophyll layer allow gases to diffuse.

87
Q

Why don’t plants keep the stomata open permanently?

A

Plants need to close the stomata to reduce the water loss

88
Q

Why do plants release more CO2 compared to O2 at night?

A

Respiration continues during the night and photosynthesis doesn’t.

89
Q

Describe the general structure of the lungs

A

-Trachea branches into two bronchi
-Bronchi branch into bronchioles
-Bronchioles terminate in alveoli

90
Q

Describe the structure of an alveolus

A

-Small sac with capillaries around them
-Contain a surfactant so walls don’t stick together and so gases can dissolve to help diffusion.

91
Q

Function of the pleural membrane

A

Cover the lungs, reduces friction and keeps them moist

92
Q

What are intercostal muscles?

A

Group of muscles found between the ribs that are involved in breathing by changing the size of the thorax.

93
Q

How do the diaphragm and intercostal muscles work together during expiration?

A

-Diaphragm relaxes and moves up
-External intercostal muscles relax
-Volume in the thorax decreases and air moves out.

94
Q

How do the diaphragm and intercostal muscles work together during inspiration?

A

-Diaphragm contracts and moves down
-External intercostal muscles contract
-Volume in the thorax increases and air moves in

95
Q

How does smoker’s cough arise?

A

-Cilia on cells lining the trachea waft mucus containing dirt out of the lungs
-Smoking can kill cells lining the trachea
-A build-up of mucus in the lungs can cause people to develop smoker’s cough

96
Q

Give 2 reasons why unicellular organisms can rely on diffusion alone

A

-They have a large surface area to volume ratio due to their size
-They have low metabolic demands

97
Q

What does the phloem transport?

A

Sugars (sucrose)

98
Q

What does the xylem transport?

A

Water and minerals (Up the plant)

99
Q

How are root hair cells adapted to their function?

A

-Long root hair extension to increase surface area
-Thin membranes to decrease the diffusion distance

100
Q

State 3 benefits of transpiration

A

-Stream of water cools the plant
-Water helps to support the plant by creating pressure
-The plant has a contant water supply for photosynthesis

101
Q

How is the xylem adapted to transport water?

A

-Waterproofed using a substance called lignin
-Xylem cells are dead and have no organelles so there is more space for water

102
Q

Describe the process of transpiration

A

-Water is lost through the stomata
-More water is drawn up to replace the lost water

103
Q

What is the transpiration stream?

A

Flow of water through a plant

104
Q

How does the temp affect the rate of transpiration?

A

-As the temperature increases, so does the transpiration rate
-Molecules have more KE and evaporation occurs faster

105
Q

How does light intensity affect the rate of transpiration?

A

-The brighter the light, the more stomata open and rate of photosynthesis increases which both decrease the amount of water in the plant
-The rate of transpiration increases

106
Q

How does wind speed affect the rate of transpiration?

A

-The faster the wind speed, the faster the water is moved away from the plant creating a steeper gradient increasing the transpiration gradient.

107
Q

Define translocation

A

Movement of sugars up or down the phloem

108
Q

Name 4 components of the blood

A

-Red blood cells
-White blood cells
-Platelets
-Plasma

109
Q

Function of platelets

A

Create blood clots

110
Q

State 2 benefits of blood clotting

A

-Prevents the entry of microorganisms
-Prevents blood loss

111
Q

Adaptations of red blood cells

A

-Contain haemoglobin
-Biconcave shape to maximise surface area and allow them to squeeze through capillaries
-No nucleus to maximise space for haemoglobin

112
Q

Purpose of plasma

A

Transport medium for CO2, hormones, nutrients and waste products

113
Q

Function of white blood cells

A

Involved in phagocytosis and some produce antibodies.

114
Q

2 ways the body can respond to detecting a pathogen

A

-Lymphocytes can produce antibodies
that are specific to the antigens on the pathogen
-Phagocytes engulf the pathogen

115
Q

How do vaccines work?

A

-Dead r inactive pathogens are injected into a body
-Body produces antibodies against the pathogen
-Memory cells are also created to provide long term immunity

116
Q

Double circulatory system

A

Heart pumps blood to lungs, the oxygenated blood returns to the heart and then is pumped around the body.

117
Q

Difference in function between veins, arteries and capillaries.

A

-Arteries: carry blood away from heart
-Veins:carry blood into the heart
-Capillaries: flow close to tissues for exchange

118
Q

Describe the structure of arteries

A

Thick walls made of muscle, elastic tissue, small lumen to transport blood under high pressure.

119
Q

Describe the structure of capillaries

A

Thin walls about one cell thick (easier to exchange substances at the tissue).

120
Q

Describe the stucture of veins

A

Larger lumen as the blood flows at a lower pressure. They also have valves to prevent backflow.

121
Q

Describe the blood flow through the left side of the heart

A

-Blood enters into the left atrium from the pulmonary vein
-The blood is them pumped through the left AV valve into the left ventricle
-Blood is the pumped through the left SL valve and into the aorta

122
Q

Describe the blood flow throught the right side of the heart.

A

-Deoxygenated blood flows through the right atrium from the vena cava.
-This blood passes through the right AV valve into the right ventricle
-The blood is then pumped out of the heart to the lungs through the right SL valve and into the pulmonary artery

123
Q

Name of the wall that separates the right and left sides of the heart.

A

The septum

124
Q

What is the name of the artery that supplies the heart tissue with blood?

A

The coronary artery

125
Q

What type of muscle is the heart made of?

A

Cardiac muscle

126
Q

Why is the wall of the left ventricle thicker than the wall of the right ventricle?

A

The left ventricle has to pump blood a further distance around the whole body so the blood needs to be under higher pressure.

127
Q

What does adrenaline do to the heart rate?

A

Adrenaline increases the heart rate as it triggers the ‘fight or flight’ reflex.

128
Q

State 2 other things adrenaline affects

A

-Dilate the pupils
-Increases the breathing rate

129
Q

Why does the heart rate increase during exercise?

A

-More muscle movement requires more energy from respiration
-The muscle tissues need to be provided with a supply of oxygen to carry out respiration and so the heart needs to pump faster to provide oxygen.

130
Q

What is coronary heart disease?

A

When the artery providing the heart tissue with blood becomes blocked.

131
Q

What two waste products do plats produce and what process produce them?

A

Oxygen is produced from photosynthesis
CO2 is produced from respiration

132
Q

What is the funtion of the kidneys?

A

-Regulate the volume and concentration of urine
-Remove waste and regulate body water content

133
Q

Describe the general structure of a kidney

A

-Contains a cortex and medula
-Renal artery carries blood to the kidney
-Renal vein carries blood away from the kidney
-Each kidney contains many nephrons
-Ureter carries fluid from the kidneys to te bladder.

134
Q

3 waste products produced in the body

A

-Urea
-Carbon dioxide
-Excess salt and water

135
Q

Name 3 excretory organs

A

-Lungs
-Kidneys
-Skin

136
Q

4 roles of the kidneys

A

-Filtration
-Selective reabsorption
-Excretion
-Osmoregulation

137
Q

What does the ureter do?

A

Carries urine from the kidneys to the bladder from excretion

138
Q

5 main parts of a kidney nephron

A

-Glomerulus
-Proximal convoluted tubue
-Loop of Henle
-Distal convoluted tubule
-Collecting duct

139
Q

Difference between ureter and urethra?

A

-Ureter leads from the kidneys to bladder
-Urethra leads from the bladder out of the body

140
Q

How does ultrafiltration work in the Bowman’s capsule?

A

-Blood vessel leading to the glomerulus is wider than the one leading away which increases the pressure of the blood as it travels along
-Small items in the blood are squeezed out under this high pressure (big proteins ad cells stay in the blood).

141
Q

State 4 components of the glomerular filtrate

A

-Urea
-Sats
-Water
-Glucose

142
Q

What is the purpose of selective reabsorption?

A

To prevent the excretion of useful substances like glucose

143
Q

What does ADH stand stand for?

A

Antidiuretic hormone

144
Q

When is ADH released?

A

When the body lacks water

145
Q

How does ADH affect the collecting duct?

A

ADH makes the collecting duct permeable to water so that more water is reabsorbed from the filtrate

146
Q

Describe the negative feedback loop when dehydration is detected

A

-Thirst signals activated
-More ADH released (water retained by kidneys

147
Q

Describe the negative feedback loop when overhydration is detected

A

-Less ADH is release
-Dilute urine is produced
-Salts are retained

148
Q

Give 3 componenets of urine

A

-Water
-Urea
-Ions

149
Q

Define homeostasis

A

Maintaining a constant internal environment despite external change.

150
Q

3 conditions which need to be controlled within the body

A

-Temperature
-Water levels
-Blood glucose concentration

151
Q

3 main parts to a coordinated response

A

-Stimulus
-Receptor
-Effector

152
Q

What does auxin trigger?

A

Growth of the main stem of the plant (and inhibits the growth of side shoots)

153
Q

Define phototropism

A

Phototropism is the growth of a plant towards a light source. The shoots are positively phototropic (grow towards the light source).

154
Q

Define geotropism.

A

Geotropism is the growth of a plant towards the pull of gravity. The roots are positively geotropic (they grow down in the same direction as the pullof gravity).

155
Q

How does auxin cause the shoots to grow towards the light source?

A

-Auxin collects on the shaded side
-Auxin promotes cell growth
-The shoot curves towards the light.

156
Q

3 differences between nervous and hormonal communication.

A

-Nervous communication uses nerve cells and impulses.
-Nervous communication is generally much faster
-Hormonal communication brings longer lasting effects than nervous communicatio

157
Q

What is the difference between the central nervous system and the peripheral nervous system?

A

The central nervous system is the brain and the spinal cord. The peripheral nervous system is every other part of the nervous system.

158
Q

How is an impulse transmitted between two neurones?

A

The impulse reaches the end of one neurone. A neurotransmitter is released and diffuses across the gap. A new impulse is triggered in the next neurone.

159
Q

What is a stimulus?

A

A stimulus is a change in the environment.

160
Q

What type of neurone connects a receptor to the CNS?

A

A sensory neurone.

161
Q

What is an effector?

A

A part of the body that brings about the response to a stimulus like a muscle or a gland.

162
Q

What type of neurone connects the CNS to an effector?

A

A motor neurone

163
Q

Describe the reflex arc

A

-Stimulus detected by a receptor
-Impulse passed along sensory neurone to CNS
-Impulse passed along motor neurone to effector
-Effector brings about the response.

164
Q

Describe the sequence of events involved in removing a hand away from a hot flame.

A

-Thermoreceptors in the hand detect the heat of the flame
-An impulse is sent along the sensory neurone
-The impulse passes through relay neurones in the CNS
-The impulse then passes along a motor neurone and triggers the muscles in the arm to move the hand away.

165
Q

Function of the cornea

A

Transparent layer in front of the eye that protects the eye from damage.

166
Q

Function of the iris

A

The coloured ring around the pupil that controls its diameter.

167
Q

Function of the pupil.

A

The pupil is the hole in the middle of the iris that lets light into the eye.

168
Q

Function of the optic nerve

A

The nerve coming coming out of the back of the eye that sends signal to the brain.

169
Q

Function of Lens

A

Focuses the light rays onto the retina

170
Q

Function of the retina

A

The retina is the back part of the eye and it converts visual stimuli into electrical impulses.

171
Q

Function of ciliary body and suspensory ligaments

A

Control the shape of lens (accomodation).

172
Q

How does the eye focus on near objects?

A

-Ciliary muscles contract and suspensory ligaments relax, causing the lens to thicken.
-Thicker lens causes the light to refract more.

173
Q

How does the eye focus on far away objects?

A

-Ciliary muscles relax and suspensory ligaments strech, which makes the lens thinner.
-Thinner lens causes the light to refract less.

174
Q

How does the eye respond to bright light?

A

The iris contracts, making the pupil smaller and letting in less light.

175
Q

How does the eye respond to a lack of light?

A

The iris relaxes which makes the pupil larger and lets in more light.

176
Q

Why does the temperature need to be controlled inside your body?

A

To provide a suitable environment for the enzymes so they can work fastest at their optimum temperature

177
Q

Give 2 processes involving the skin that cool the body down

A

Sweating-Cools the body down by evaporation
Vasodilation-Allows blood to flow closer to the surface of the skin where it can cool

178
Q

Describe the process of vasodilation

A

-Boody detects a rise in temp
-Blood vessels supplying the capillaries at the skin surface dilate (muscles in the vessels relax)
-More blood flows closer to the skin where it can cool

179
Q

Give 3 processes that work to keep the body warm

A

-Vasoconstriction
-Shivering
-Erection of hairs on the skin

180
Q

Describe the process of vasoconstriction

A

-Blood detects a drop in temp
-Blood vessels supplying the capillaries att the skin surface constrict (muscles in the vessels contract)
-Less blood flows closer to the skin surface so less heat is lost to the surroundings.

181
Q

Define hormones

A

Hormones are chemical messengers that are secreted by glands of the endocrine system into the bloodstream.

182
Q

What does insulin do to the body?

A

Decrease blood glucose concentration

183
Q

Where is insulin secreted from

A

The beta cells of the pancreas

184
Q

Where is testosterone secreted from

A

The testes

185
Q

What does testosterone do?

A

-Main male sex hormone
-Involved in the growth of testes and penis
-Triggers many changes in males during puberty

186
Q

When is adrenaline secreted?

A

During times of anxiety, fear or stress.

187
Q

Where is adrenaline released from?

A

Adrenal glands

188
Q

3 effects of adrenaline

A

-Increases heart and breathing rate
-Increases blood glucose concentration
-Dilates the pupils

189
Q

What does estrogen do and where is secreted from?

A

Causes the uterus lining to thicken. Its secreted from the ovaries

190
Q

What hormone does estrogen inhibit

A

FSH (follicle stimulating hormone)

191
Q

Function of progesterone and where is it secreted from

A

Maintains the womb lining and its secreted from the ovaries

192
Q

What hormone does progesterone inhibit?

A

FSH

193
Q

Function of FSH

A

Stimulates the follicle to mature and release estrogen

194
Q

What does luteinising hormone (LH), do?

A

surge in LH causes the release of an egg from a follicle

195
Q

Where is FSH secreted from?

A

Anterior pituitary gland

196
Q

Where is ADH secreted from?

A

Posterior pituitary gland

Biology (5 decks)

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