biology Flashcards

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1
Q

what is a cell and what does it do

A

a cell is a basic block of life it take in raw materials can converts them into molecules which are used to fulfil different functions

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2
Q

protoplasm

A

protoplasm is the living matter of the life and is made of the nucleus , cytoplasm and the cell membrane

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3
Q

cytoplasm

A

the cytoplasm is a jellylike substance it is the site most of the chemical reactions take place it contains specialized structures known as organelles

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3
Q

the cell membrane

A

surround the cytoplasm it is made out proteins and lipid and it is partially permeable so allowing smaller soluble substance to diffuse through the membrane therefore the function is to control the movement of substances going in and out of the cell

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4
Q

nucleus

A

the nucleus controls all the activities that occur in the cell and is essential for cell division it consist of a chromatin and a nuclear membrane

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5
Q

the chromatin

A

chromatin a long tread like structure that contains a compound known as deoxyribonucleic acid DNA which contain hereditary information and during cell division the chromatin condenses into a short thick rod shape structure known as chromosomes

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6
Q

nuclear membrane

A

it separates the content of the nucleus from the rest of the cell

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7
Q

rer rough endoplasmic reticulum

A

the rough endoplasmic reticulum is a network of flattened spaces lined with a membrane
the outer surface is continuous with a nuclear envelope
the surface of the rough endoplasmic reticulum has ribosomes attached to it therefore making it rough
the function of the rough endoplasmic reticulum is to transport proteins made by the ribosome into the Golgi body

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8
Q

ribosome

A

the ribosome are small circular structures that can either be seen lying freely around the cytoplasm or attached to the surface of the rough endoplasmic reticulum
its function is the synthesis of proteins

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9
Q

SER smooth endoplasmic reticulum

A

the smooth endoplasmic reticulum is more tubular than the rough endoplasmic reticulum it does have any ribosomes attached to the surface and therefore smooth its function is to synthesis substances like steroids and lipase and is involved in neutralization

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10
Q

Golgi body

A

the Golgi body consist of flatten spaces surrounded by a membrane it function is to modify substances made by the ser and rer and is then stored and packaged as vesicles and secretes out of the cell through the cell membrane

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11
Q

mitochondrion

A

it is the power house of the cell it a oval or sausage like structure that helps to release energy for the cell through aerobic respiration by oxidizing with food molecules to release energy for cellular activities

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12
Q

the process of substance being transported from the endoplasmic reticulum to the the Golgi body and out the cell

A

the vesicles containing substances from the endoplasmic reticulum is pinched off the endoplasmic reticulum and the vesicles fused into the Golgi body which is then modified and the secreted vesicles is then pinched out the Golgi body and the secretory vesicles then fuse with the cell membrane and the content is release out of the cell

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13
Q

chloroplast

A

chloroplast is a oval shape structure and contains a pigment known as chlorophyll which helps to absorb sunlight needed for photosynthesis

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14
Q

vacuole

A

the vacuole is a fluid filled space that stored substances within the cell and is enclosed by a partially permeable membrane
the animal vacuole are tiny and numerous and stores substances such as water and food substance and they temporarily exist
while the plant vacuole is large and central vacuoles and carries substances such as amino acids sugars and mineral salts

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15
Q

cell wall

A

a cell wall surrounds the cell membrane it is fully permeable and it is made out of cellulose it gives the plant a fixed shape and prevent the plant from injuries

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16
Q

muscle cell

A

muscle cell contain numerous mitochondria to provide energy for muscles contractions and it has contractile protein fibers for contraction and relaxation to bring about movement
it has numerous nucleus for cell division

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17
Q

the root hair cell

A

the root hair cell has a narrow and long extension to increase the surface area to volume ratio to maximize the rate of absorption of water and mineral salts
the vacuole maintains a lower water potential this ensure water is able to diffuse through the membrane through osmosis

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18
Q

additional stem cell

A

scientist can take them transform them into different organs and is transplanted into a person

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19
Q

what is diffusion

A

diffusion is the net movement of particles from a region of higher concentration to a region of lower concentration down a concentration gradient until equilibrium is reached

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20
Q

how is concentration gradient related to diffusion

A

the motion of particles are random and the particle diffuse down the concentration gradient which the steep the concentration gradient the greater the rate of diffusion

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21
Q

diffusion across a membrane

A

when both substance can pass through the partially permeable membrane diffusion also occurs

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22
Q

what affects the rate of diffusion

A

the rate of diffusion is affected by the temperature the steepest of the concentration gradient and the diffusion distance
nature of solvent and mass of solute

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23
Q

why are the walls of the blood capillaries one cell thick

A

as this is to decrease the diffusion distance and this increases the rate of diffusion ensuring maximum efficiency of the exchange of substances

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24
Q

how does oxygen get from the leaves to the root

A

the oxygen diffuses down a concentration gradient from a higher concentration in the roots to a lower concentration in the hair root cell

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25
Q

why do the small intestine have folded membranes

A

as this is to increase the surface area to volume ratio and increase the rate of diffusion ensuring maximum efficiency of nutrient flowing into the capillaries

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26
Q

why does the viscosity of the solvent and the mass of the solute matter

A

as the went a solvent is more viscous which means its dense and thicker this would decrease the rate of diffusion as the particles have a difficult time
and when the solute is greater in mass this means the particles are heavier which decreases the rate of diffusion

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27
Q

what is osmosis

A

osmosis is the net movement of water molecules from a greater water potential to a lower water potential through a partially permeable membrane

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28
Q

what happens if in a dialysis tubing with 20 % sucrose solution surrounded by distilled water

A

through osmosis the water has a higher water potential than the sucrose solution so the water moves down a water potential gradient through the partially permeable membrane and the net movement only stops when equilibrium is reached

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29
Q

how is water potential gradient related to osmosis

A

as the water molecules are in a constant motion and the water molecules move down a concentration gradient

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30
Q

factors that affect osmosis

A

surface area to volume ratio, the distance of water molecules needed to move and water potential gradient

31
Q

what happens to plant cell in higher water potential solution

A

so the water has a greater water potential than the cell sap of the plant so water enter through osmosis and plant cells expands and become turgid and it does not burst as there is a cell wall that ensures the fixed shape of the plant

32
Q

a red blood cell in distilled water

A

there is greater water potential in the distilled water than the red blood cell so water enters the red blood cell through osmosis and the red blood cell expands and burst

33
Q

plant cell in a lower water potential solution

A

the cell sap in the plant has a greater water potential than the lower water potential solution so water leaves the cell sap through osmosis and plant cell becomes flaccid and the cytoplasm shrinks away from the cell wall and it become plasmolyzed

34
Q

red blood cell in a sugar solution

A

the red blood cell has a higher water potential than the sugar solution so water leaves the red blood cell through osmosis and the red blood cell shrinks and become crenated and becomes spiky in shape

35
Q

how does turgor play a role in plants

A

as it helps keep the plant stay upright an firm due to it being turgid while if the cell was flaccid the plant would start to wilt

36
Q

what is active transport

A

active transport is used of cellular energy when particles of substance move across a membrane against a concentration gradient from a lower concentration to a high concentration

37
Q

is active transport used to absorb mineral salts

A

yes active transport is used to absorb dissolved mineral salt when there is a higher concentration in the root than the soil so it goes a against the concentration gradient enquiring all of energy through respiration

38
Q

why do we eat and what are 3 main nutrient

A

as it provides the body with energy and materials needed for the body and the 3 main nutrients are the carbohydrates , proteins and fats

39
Q

why is water needed

A

as water makes up 70% of our body it is a greater solvent for many chemical reactions it keeps cells firm and turgid help transport mineral salts in plants it help to regulate body temperature and transport dissolved substances around the body

40
Q

formula for carbohydrates

A

carbohydrates contains of 3 elements such a carbon , oxygen and hydrogen
the ratio for carbohydrates is always 2 is to 1

41
Q

what are the different groups of carbohydrates classified as

A

they are monosaccharide such as glucose and fructose disaccharide such as maltose and sucrose and polysaccharide which include starch, cellulose and glycogen

42
Q

properties of single and double and complex sugar

A

basic unit of carbohydrates glucose is found in both animal and the plants while fructose is only found in plants rarely in human

maltose in found in malt sugars formed by 2 glucose molecules
sucrose is found in fruits or cane sugars formed by one fructose and a glucose molecule

complex sugars made of many glucose molecules joined together in different ways forming starch which is a form of storage in plant cellulose which is a dietary fiber found in cell walls and glycogen a storage of glucose in liver and muscles in mammals

43
Q

what is benedicts test for and what happens

A

the benedicts test is used to test for the presence of reducing sugars which is all the mono and disaccharides except for sucrose
brick red means there is a large amount of reducing sugars precipitate and if there is a orange precipitate there is a moderate amount of reducing sugars and if there is yellowish green precipitate there a small amount of reducing sugar and if the solution remains blue there is not presence of reducing sugars

44
Q

how to conduct a benedicts test

A

add 2cm2 of the food sample into a test tube and add to 2cm2 of benedicts solution into the same test tube and shake well and place the test tube in a beaker of boiling water for 5 minutes and obverse the precipitate formed

45
Q

what happens during vigorous activities

A

during vigorous activities the muscles contract vigorously and aerobic respiration in muscles cells start to increase and the heart rate increase to supply more oxygen and the breathing rate increases to obtain more oxygen
however when aerobic respiration is not able to meet the increased energy demands anaerobic respiration takes place to meet the energy demands
lactic acid accumulates in the muscles cell resulting in oxygen debt

46
Q

what is oxygen debt

A

oxygen is the amount of oxygen needed to remove lactic acid

47
Q

why are our heart rate and breathing rate still fast after a run

A

as to make sure the oxygen uptake is higher enough to replenish oxygen debt

47
Q

how is lactic acid removed

A

as there is lactic acid accumulated in the muscles cell which in high levels can be toxic for the body and result in fatigue or cramps
so lactic acid from the cell are transported to the liver to break the lactic acid into harmless forms
so the heart rate increases to supply more oxygen to the liver at a faster rate and transport the lactic acid from cells to the liver and breathing rate increases to obtain more oxygen supplied to the liver

48
Q

wat does potassium hydroxide do

A

remove co2

49
Q

lime water in presence of co2

A

the limewater turns cloudy

50
Q

hydrogencarbonate indicator when co2 present

A

since co2 is slightly acidic it will turn the hydrogencarbonate indicator from red to yellow

51
Q

why is there a layer of oil in anaerobic respiration

A

to prevent oxygen from atmosphere to interfere with the experiment preventing yeast to respire aerobically

52
Q

why boil glucose in a test for anaerobic respiration

A

to remove oxygen and carbon dioxide in glucose so carbon dioxide does not interfere with the test of anaerobic respiration

53
Q

what is observed in limewater in an anaerobic respiration test

A

cloudy as when yeast anaerobically respire they produce carbon dioxide turning it cloudy

54
Q

flow of air in human

A

nasal passage pharynx , larynx , trachea bronchi bronchioles and alveoli [ air sacs]

55
Q

nasal passage

A

air enter through the 2 external nostrils the walls of the nasal passage are surrounded by a fringe of hair and the nostril lead in to 2 nasal passage are lined with a moist mucus membrane the fringe of hair and the layer of mucous is meant trapped all the dust and foreign particles bacteria
and the mucous membrane has small sensory cells that detect harmful chemicals
and in the nasal passage it is moisten and warm

56
Q

pharynx and larynx

A

air from the nasal passage and into the pharynx and from pharynx enters the larynx and air enters through the openings of the trachea

57
Q

bronchi and bronchioles

A

the trachea divides into 2 bronchi and each bronchus carries air into each lungs the structure of the bronchus is similar to that of a trachea and its a c- shaped cartilage and the bronchus branches out repeatedly to give rises to numerous bronchioles which are fine tube and the end of the bronchioles have a cluster air sac or a alveoli

57
Q

the trachea

A

it has a c-shaped cartilage that helps keep the lumen open the membrane next to the lumen is the trachea epithelium the epithelium consist of gland cells which secrete mucus to trap dust and bacteria and ciliate cells that are hair like structure which is cilia found on the surface that help sweep up mucus dust trapped particles up to the larynx and to the pharynx

58
Q

alveoli

A

gas exchanges takes place at the walls of the alveoli and there is numerous number of alveoli found the lung to increase surface area to volume ratio to increase rate of diffusion and maximize the rate of gas exchange

59
Q

how does the lung adapt to efficient gas exchange

A

there are numerous alveoli found in the lung as this is to increase the surface area to volume ratio to increase the rate of diffusion and maximizing the rate of gas exchange making it efficient

the walls of the alveoli and the blood capillaries are one cell thick only as this is to ensure the diffusion distance between the blood capillaries and the alveoli is short and this would help increase the rate of diffusion and increases rate of gas exchange

there is a thin film of moisture that covers the inner wall of alveolus this helps to dissolve the oxygen for an easier diffusion across the alveoli walls

the walls of the alveolus is richly supplied with blood capillaries this allows blood rich in oxygen to quickly be away from the alveolus and blood rich is carbon dioxide to the alveolus quickly this ensures a steep concentration gradient to increase the rate of diffusion of carbon dioxide entering the alveolus and oxygen leaving the alveolus into the walls

60
Q

how does gas exchange occur in the alveoli

A

gas exchange occurs through diffusion where the concentration of oxygen in the alveolar air is lower than the atmospheric air and the concentration of carbon dioxide in the alveolar air is greater than the atmospheric air this therefore creates a concentration gradient from both carbon dioxide and oxygen between the alveolus air and the blood and gas exchange occurs

61
Q

breathing mechanism dirt laa inhalation

A

during inspiration the diaphragm contracts and the diaphragm muscles flatten downward the internal intercoastal muscles relax and the external intercoastal muscles contract this cause the ribs to move upward and outwards and the thoracic cavity increases in volume and the lungs expand and the air pressure in the lung decreases the volume increases so the atmospheric pressure is greater than the air pressure in the lungs causing air to be force in to the lung

62
Q

describe the process of oxygen and carbon dioxide entering and leaving

A

so oxygen from the alveoli is dissolved into the thin film of moisture and then it diffuses through the walls of the alveoli and the the walls of the blood capillary and bind with the haemoglobin to form oxyhaemoglobin and is transported to the pulmonary veins and and the carbon dioxide in the blood diffuses through the walls of the blood capillaries and the walls of the alveoli where it enters the alveolar air and is transported out of the body

63
Q

thoracic chest cavity

A

the chest wall are supported by the rib cage which the 2 sets of muscles found in the thoracic chest cavity which is the internal intercoastal muscles and the external intercoastal muscles and are antagonistic in action

the thorax is separated from the abdomen with a domed shaped diaphragm made out muscles and elastic tissue when the diaphragm contract the diaphragm muscles flatten downwards and when the diaphragm relax the diaphragm muscles arched upwardsn

64
Q

exhalation dirtlaa

A

during expiration the diaphragm relax the diaphragm muscles aches downward and the internal intercoastal muscles contract and the external intercoastal muscles relax and the rib cage moves downward and inwards and the volume of the thoracic cavity decreases so the lungs are compressed and the air pressure in the lung increases as the volume decreases and the air pressure in the lungs to be greater than the atmospheric pressure causing air to be forced out of the lungs

65
Q

nicotine

A

nicotine causes addiction and this increases the release of a hormone called adrenaline which this increase the heart rate and the blood pressure narrowing the arteries and this could increase the risk of blood clot and increase the risk of heart disease such as coronary heart disease

66
Q

Tar

A

tar contains carcinogenic which is cancer causing which results in uncontrollable cell division
it paralyzed the cilia lining the air passage so dust trapped mucus is unable to be removed in the lung so the lungs compensates by secreting more mucus which traps more dust and bacteria which can result in lung infection and increases the risk of chronic bronchitis and emphysema and reduces the efficiency of gas exchange as tar can coat the inner walls of the alveoli and decrease the surface area and reducing the rate of diffusion and decreasing efficiency of gas exchange as it reduces the available for the exchange of gases to take place

66
Q

carbon monoxide

A

carbon monoxide decrease the ability of oxygen being able to bind with the haemoglobin as it bind with carbon monoxide irreversibly with haemoglobin to form carboxyhaemoglobin and this prevents oxygen to bind with haemoglobin this decrease the supply of oxygen to vital organs such as the brain and the heart this can result in a breathlessness and organ failure and increase the rate of which fats are deposited into the arterial walls which increases the risk of atherosclerosis or coronary heart disease

67
Q

irritant

A

irritants such as hydrogen cyanide formaldehyde which their paralyze the cilia lining the air passage and the dust trapped mucus cannot be removed and the lungs compensate by secreting more mucus from the gland cells and this increases the amount of bacteria and dust trapped and increase the risk of chronic bronchitis and emphysema

67
Q

chronic bronchitis

A
67
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A
68
Q
A
69
Q
A
70
Q
A