Topic 2: Organisation Flashcards
What features do gas exchanges surfaces have to increase efficiency?
-Large surface area to allow faster diffusion of gases across the surface
- Thin walls to ensure diffusion distances remain short
- Good ventilation with air so that diffusion gradients can be maintained
- Good blood supply (dense capillary network) to maintain a high concentration gradient so diffusion occurs faster
What process does gas exchange occur by?
Diffusion
What is the function of the ribs?
- Bone structures that surround and protect lungs
- Aid breathing
What is the function of the intercostal muscles?
- Muscles between ribs which control movement
- Cause inhalation and exhalation
What is the function of the diaphragm?
- Sheet of connective tissue and muscle at bottom of thorax
- Change volume of thorax to allow inhalation and exhalation
What is the function of the trachea?
- Windpipe that connects mouth and nose to the lungs
- Lined with goblet cells ( to produce mucus)
- Ciliated with epithelial cells ( cilia to move mucus up mouth)
What is the function of the bronchus/bronchi?
- Large tubes branching off trachea
- One bronchus for each lung
- Lined with goblet cells ( to produce mucus)
- Ciliated with epithelial cells ( cilia to move mucus up mouth)
What is the function of the bronchioles?
- Small tubes
- Connect lungs to alveoli
What is the function of the alveoli?
- Tiny moist air sacs
- Gas Exchange takes place
- Covered in capillaries
What system is the heart a part of and what does it include?
Double-circulatory system
- System of:
> Blood Vessels
> Pump (Heart)
> Valve to maintain one-way flow
How many chamber does the heart have?
Four chambers separated into two halves
Describe the right side of the heart
- Pumps blood to lungs for gas exchange
- Pulmonary Circuit
Describe the left side of the heart
- Pumps blood under high pressure to body
- Systemic Circulation
What are the benefits of a double circulatory system?
- Blood travelling through the small capillaries in the lungs loses a lot of pressure which reduces the speed at which it can flow meaning more time for diffusion of gases at the alveoli
- By returning oxygenated blood to the heart from the lungs, the pressure can be raised before sending it to the body, meaning cells can be supplied with oxygenated blood more quickly
Describe how blood travels through the heart
- Right Side receives deoxygenated blood
Vena Cava –> Right Atrium –> Heart Valve –> Right Ventricle - Pumped up to lungs
- Oxygen diffuses in from alveoli and Carbon Dioxide diffuses out
Pulmonary Vein –> Left Atrium –> Heart Valve –> Left Ventricle –> Aorta - Pumped around body
What are the top chambers in a heart known as?
Atria
What are the bottom chambers in a heart known as?
Ventricles
What are coronary arteries?
- Found outside heart
- Supply cardiac muscle cells with nutrients and remove waste products
- Supply tissue of heart with oxygenated blood
What are the adaptations of the ventricles?
- Ventricle Walls much thicker than atria walls as they are responsible for pumping blood out of the heart and so need to generate a higher pressure
- Left Ventricle Wall is much thicker than Right Ventricle as it has to pump blood at high pressure around the entire body
- Right ventricle pumps blood at lower pressure to the lungs which are close to the heart so do not require high-pressure
What are the valves needed for?
- Twos sets in heart
- Prevent backflow of blood
What is the septum and what is it used for?
- Separates two sides of heart
- Prevent mixing of deoxygenated and oxygenated blood
What happens if there was no septum and blood was to mix?
Less oxygenated blood would be pumped around body
What muscle is the heart made of?
- Special cardiac muscle tissue
- Does not fatigue like skeletal muscle
Why does the coronary arteries need to supply heart with blood?
The heart needs a constant supply of oxygen (and glucose) for aerobic respiration to release energy to allow continued muscle contraction
What is the natural heart rate controlled by?
- Group of cells
- Pacemaker
- Located in right atrium
What is the role of the pacemaker?
Coordinate the contraction of heart muscle, regulates heart rate
Why is there a change in heart rate?
- When a person is at rest, the oxygen demand of their cells is relatively low and so a lower heart rate is maintained
- When a person is exercising, the oxygen demand of their muscle cells increases so a higher heart rate is necessary
How does the pacemaker cause the heart to contract?
Sends an electrical impulse which spreads surrounding muscle cells of heart, causing them to contract
What are artificial pacemakers and why are they used?
- Electrical devices used to correct irregularities in heart rate
- Sometimes, pacemaker of heart stops functioning properly
- Device implanted under skin, with a wire that delivers electrical current to heart
What are the three types of blood vessels?
Arteries: transport blood away from the heart (usually at high pressure)
Veins: transport blood to the heart (usually at low pressure)
Capillaries: links arteries to veins within the tissues of the body
What is the structure of a blood vessel?
- Structure relates to function of the vessel
- Blood flows through the lumen of a blood vessel; the size of the lumen varies depending on the type of blood vessel (with arteries having a narrow lumen, and the veins a wider one)
- Lumen of the capillaries is extremely narrow, at the smallest the width of a red blood cell!
How does the structure of an artery relate to its function?
- Arteries must withstand and maintain high pressures from the contracting and relaxing heart
- Their thick walls contain collagen, smooth muscle, and elastic fibers
- The elastic fibers allow expansion and recoil, maintaining high blood pressure alongside a narrow lumen
How does the structure of a vein relate to its function?
- Veins receive low-pressure blood from capillaries and return it to the heart
- Thinner walls with fewer layers of collagen, smooth muscle, and elastic fibers, but a much larger lumen
- Contain valves to prevent backflow
How does the structure of a capillary relate to its function?
- Capillary walls consist of a single layer of endothelial cells, minimising the diffusion distance for oxygen and carbon dioxide
- These walls have pores that allow blood plasma to leak out and form tissue fluid
What is the equation for rate of blood flow?
Rate of Blood Flow = Volume of Blood / Number of Minutes
What is blood and what is it used for?
- Tissue consisting of fluid plasma suspending red and white blood cells and platelets
- Used to transport useful substances to every cell of body
- Removes harmful waste substances
- Transfers heat from active organs to cooler parts of body
What are red blood cells?
- Cells with distinctive biconcave shape
- Large surface to volume ratio to maximise efficiency of diffusion of gases
- Cytoplasm packed with protein haemoglobin which binds with oxygen
What is the primary role of white blood cells (WBCs) in the immune system?
WBCs defend the body from infection by recognising and destroying pathogens
What are the three main ways WBCs defend the body?
1) Phagocytes engulf and digest pathogens.
2) Lymphocytes produce antibodies to enhance phagocyte activity or disable pathogens.
3) Some lymphocytes produce antitoxins to neutralise toxic substances from pathogens.
What do phagocytes do to pathogens?
Phagocytes engulf and digest pathogens, destroying them.
What role do lymphocytes play in the immune response?
Lymphocytes produce specific antibodies that help phagocytes by clumping pathogens together or disabling them. Some lymphocytes also produce antitoxins.
What is the function of antitoxins produced by lymphocytes?
Antitoxins bind to toxic substances produced by pathogens, neutralising them.
What adaptation do phagocytes have to help them perform their function?
Phagocytes have a lobed nucleus and are autonomous—they leave the blood and patrol the tissues
What adaptation do lymphocytes have to help them perform their function?
Lymphocytes have a large nucleus and can produce antibodies extremely quickly
What are platelets and what are they needed for?
- Fragment of cells (contain cytoplasm but no nucleus)
- When damage to blood vessel occurs, platelets involved in forming blood clot to prevent blood loss
What are unicellular organisms?
Made from one cell
What are multicellular organisms?
Made up of a collection of cells
What is a cell?
Basic functional and structural units in a living organism
What is a tissue?
A group of cells of similar structure working together to perform a particular function
What is an organ?
Made from a group of different tissues working together to perform a particular function
What is an organ system?
Made from a group of organs with related functions, working together to perform body functions within the organism
What is the stomach’s role?
- Churning food to break into smaller pieces
- Producing protease enzymes
> e.g pepsin, digest proteins into amino acids
What is digestion?
- Large, insoluble molecules in food are broken down into smaller, soluble molecules that are absorbed into bloodstream and delivered to cells in body
What are the small soluble molecules produced in digestion used for?
- Provide cells with energy
- Build other molecules to grow, repair and function
What is the alimentary canal?
- Channel or passage through which food flows through the body, starting at the mouth and ending at the anus
- Where digestion occurs
What are accessory organs in the human digestive system?
- Produce substances that are needed for digestion to occur (such as enzymes and bile) but food does not pass directly through these organs
What is the function of the mouth/salivary glands?
- Mechanical Digestion
- Teeth chew food to break down size
- Amylase Enzymes in saliva start digesting starch to maltose
What is the function of the oesophagus?
- Tube that connects mouth to stomach
- Food Bolus goes after being swallowed
- Wave-like contractions push bolus down without relying on gravity
What is the function of the stomach?
- Mechanically digested by churning actions
- Protease Enzymes start to chemically digest proteins
- Hydrochloric Acid present to kill bacteria in food and provide optimum pH for protease enzymes to work
What is the function of the small intestine?
- Duodenum: Finish digest food from stomach with enzymes produced in here and pancreas
- pH is slightly alkaline (8-9)
- Ileum: Absorption of digested food molecules (lined with villi to increase SA where absorption can take place)
What is the function of the large intestine?
- Water is absorbed from remaining material in colon to produce faeces
- Stored in rectum than removed through anus
What is the function of the pancreas?
- Produces ALL THREE digestive enzymes: Amylase, Protease and Lipase
- Secretes enzymes in alkaline fluid into duodenum for digestion to raise pH coming out of stomach
What is the function of the liver?
- Produces bile to emulsify fats (mechanical digestion)
- Amino acids not used t make proteins are broken down here, producing urea (deamination)
What is the function of the gall bladder?
Stores bile to release into duodenum when required
Why does the microbial ecosystem play an essential role in digestion?
- Breaking down substances we can’t digest
- Supplying essential nutrients
- Synthesising vitamin K
- Providing competition with harmful bacterial to restrict growth
What is the function of digestive enzymes?
- Work outside cells
- Digest large, insoluble food molecules into smaller, soluble molecules which can be absorbed by the bloodstream
What is metabolism?
Sum of all reactions happening in a cell or organism, in which molecules are synthesised (made) or broken
What are enzymes and what are they used for?
- Biological catalyst
- Made from protein
- Speed up chemical reactions
- Occur at much faster speeds than they would without enzymes at relatively low temp.
What are substrates?
Temporarily bind to active site of an enzyme, which leads to a chemical reaction and the formation of a product which is released
What are the speeds of enzymes?
- Remain unchanged after reaction so can work very quickly
- Process 100s or 1000s of substrates per second
How are enzymes specific?
- Catalyses specific chemical reaction: one enzyme catalyses one reaction
- Complementary nature of active site on enzyme and its substrate
Why are enzymes in a specific three-dimensional shape?
- Formed from protein molecules which are chains of amino acids held together by bonds
- Order of amino acids determines shape of enzyme
- if order is altered, three-dimensional shape changes
What is the lock-and-key theory?
- Explains enzyme action
- Enzyme is lock, substrate is key that fits active site
How do enzyme and substrates react?
- Move randomly in solution
- Enzyme and complementary substrate randomly collide
- Enzyme-substrate complex forms and reaction occurs
- Product forms from substrate which is then released from active site. Enzyme is unchanged and will go on to catalyse further reactions
How does temperature affect enzyme activity?
- Enzymes work fastest at optimum temp., approx. 37°C in human body
- Heating to high temp. will start to break bonds that hold enzyme together
- Active site loses shape, reduces activity and eventually denatures
Why is an increasing temp. up to 37°C increase activity of enzymes?
- More energy to molecules, faster movement
- Number of collisions increases, faster rate of reaction
- Low temp. don’t denature but collide at a lower rate
How does pH affect enzyme activity?
- Optimum pH is 7, but some produced in acidic conditions (stomach) have lower optimum pH (2) and some produced in alkaline conditions (duodenum) have higher pH (8/9)
- Too low or high of pH bonds that hold amino acids can be destroyed
- Active site denatures and activity stops
What is the purpose of digestion?
To break down large insoluble molecules into smaller soluble molecules that can be absorbed into the bloodstream
What are enzymes?
Biological catalysts that speed up chemical reactions without being used up or changed in the reaction
What are the three main types of digestive enzymes?
Carbohydrases proteases and lipases
What do carbohydrases break down and into what?
Carbohydrases break down carbohydrates into simple sugars
What is amylase and what does it break down?
Amylase is a carbohydrase that breaks down starch into maltose
What does maltase break down and into what?
Maltase breaks down maltose into glucose
Where is amylase produced in the body?
Amylase is made in the salivary glands the pancreas and the small intestine
What are proteases and what do they break down?
Proteases are enzymes that break down proteins into amino acids
Where are proteases produced in the body?
Proteases are made in the stomach (pepsin) the pancreas and the small intestine
Where does protein digestion take place?
In the stomach and small intestine
What do lipases break down and into what?
Lipases break down lipids (fats) into glycerol and fatty acids
Where are lipase enzymes produced?
Lipases are produced in the pancreas
Where are lipases secreted to?
Lipases are secreted into the duodenum
What are the key roles of the pancreas in digestion?
Producing digestive enzymes and hormones that regulate blood sugar (insulin and glucagon)
Where is bile produced and stored?
Bile is produced in the liver and stored in the gallbladder
What is the first main role of bile?
It is alkaline to neutralize hydrochloric acid from the stomach
What is the second main role of bile?
It breaks down large drops of fat into smaller ones increasing surface area (emulsification)
What is emulsification and why is it important?
Emulsification is breaking down large fat droplets into smaller ones increasing surface area for lipase to work faster
Why do small intestine enzymes need a more alkaline environment?
Small intestine enzymes have a higher (more alkaline) optimum pH than those in the stomach
How are the products of carbohydrate digestion used?
Some glucose is used in respiration to release energy to fuel cell activities
How are the products of protein digestion used?
Amino acids are used to build proteins like enzymes and antibodies
How are the products of lipid digestion used?
They can be used to build new cell membranes and hormones
What is the complete breakdown path of starch digestion?
Starch → Maltose (via amylase) → Glucose (via maltase)
What is the general breakdown path of protein digestion?
Proteins → Amino acids (via proteases)
What is the general breakdown path of lipid digestion?
Lipids → Glycerol and fatty acids (via lipases)
What is CHD?
- Involves layers of fatty material (called plaque) building up inside the coronary arteries
- Partially and completely blocked and blood flow through arteries is reduced
- Lack of oxygen for heart muscle
What are the types of blockage in CHD?
- Partial Blockage: Restricted blood flow to cardiac muscle cells and result in severe chest pains
- Complete Blockage: Cell in area of the heart will not be able to respire aerobically, leading to heart attack
What are the two ways to treat CHD?
- Increasing width of lumen using a stent
- Prescribing statins to lower blood cholesterol
What are stents and how are they used?
- Used to keep coronary arteries open
- Narrow tube is threaded up to blocked vessel
- Tiny balloon is inflated
- Balloon pushes stent against wall of artery, increasing width
- Balloon and tube is removed
Why are stents effective?
- Reduces risk of heart attack as they widen lumen and increase blood flow to coronary arteries
- Simple procedure
- Lasts a long time
What are the main disadvantages of stents?
- Risks of blood clots occurring
- Risk of infection during surgery
- Risk of damage to blood vessel during surgery
What are statins and how are they used?
- Drugs used to reduce cholesterol levels in blood
- Block enzyme in liver which makes cholesterol
- Slows rate of fatty material build-up reducing risk of CHD
What are the advantages of statins?
- Reduces ‘bad’ cholesterol in blood
- Increases ‘good’ cholesterol which removes ‘bad’ cholesterol from circulating in blood
What are the disadvantages of statins?
- Need to betaken regularly and long-term
- Take some time to have effect
- Side effects: Muscle & Joint Pain, Kidney problems
What are faulty heart valves?
- Valves stiffen which prevent them from opening fully and reduces volume of blood pumped by the heart
- Can develop leak and have backflow of blood
- Reduce effectiveness of heart in pumping oxygenated blood around body
How can faulty valves be replaced?
- Via surgery
- Biological valves from cows or pigs
- Mechanical valves
What are the advantages of biological and mechanical valves?
Biological: Highly effective, Less likely to leak
Mechanical: Long lasting, Less need to replace
What are the disadvantages of biological and mechanical valves?
Biological: Replacement after 12-15 years, risk of immune rejection
Mechanical: Increase likelihood of blood clots so lifelong medication must be taken
What are artificial hearts?
- Long waiting list for organ transplants
- Immediate solution
- Keep patients alive and allow heart to rest
What are the advantages and disadvantages of artificial hearts?
Advantages: Short waiting times, less chance of rejection
Disadvantages: Do not work as well, increase blood clots and chance of stroke
What is health?
Health is the state of physical and mental well-being; lots of factors affect the health of an individual.
What are the two main categories of diseases and how do they affect individuals and society?
Diseases are categorized as communicable and non-communicable and are major causes of ill health. Ill-health affects not only the sufferer but also their family members and reduces the contribution that individual can make to society.
What are two major consequences of ill health?
Ill health can lead to a poorer quality of life or reduced lifespan.
What is the economic cost of an individual being ill?
Individuals who are sick may not be able to work and may require expensive healthcare (with the cost being attributed to the individual or a healthcare provider such as the NHS in the UK).
What are communicable diseases and what causes them?
Communicable diseases are caused by microorganisms called pathogens which can spread between individuals or individuals and animals.
Give examples of communicable diseases and their causative pathogens.
Chickenpox, a common childhood disease, is caused by a viral pathogen called the varicella-zoster virus, whereas COVID-19 is caused by the SARS-CoV-2 virus.
What are non-communicable diseases and their characteristics?
Non-communicable diseases are not caused by pathogens and their effects on health tend to be longer-lasting; examples are asthma, CHD (coronary heart disease) and most cancers.
What factors can have a profound effect on both physical and mental health?
Factors including diet, stress and life situations may have a profound effect on both physical and mental health.
How does diet impact health?
Eating a balanced diet that provides the right amount of energy and nutrients helps maintain good health whereas a poor diet can lead to deficiencies, obesity, diabetes and poor mental health.
What health problems can result from chronic stress?
Constantly being under stress can lead to cardiovascular issues (such as high blood pressure, increasing the risk of CHD) and poor mental health.
How do socioeconomic factors impact health?
Where a person lives and their income can have a profound impact on health - this affects the standard of healthcare that is accessible to them (and what they can afford), what food they buy, etc.
How can different types of diseases interact?
Different types of disease may interact in ways that negatively affect the health of the individual.
How do immune system defects affect susceptibility to disease?
Defects in the immune system mean that an individual is more likely to suffer from infectious diseases; individuals infected with HIV eventually end up with reduced numbers of lymphocytes circulating around the body which reduces the ability of the immune system to fight opportunistic infections like pneumonia.
How can viruses trigger cancer?
Viruses living in cells can be the trigger for cancers; the HPV virus can infect cells of the cervix in women resulting in cervical cancer developing in some cases, whereas some strains of the hepatitis virus can cause liver cancer.
What is the relationship between pathogens and allergies?
Immune reactions initially caused by a pathogen can trigger allergies such as skin rashes and asthma - these often develop as a result of an overactive immune response.
How can physical illness affect mental health?
Severe physical ill health can lead to depression and other mental illness.
What are disease risk factors?
- Increase rate of disease but doesn’t guarantee individual suffers from disease
What are some common risk factors and what they are linked to?
Smoking- Lung Disease/Cancer, Cardiovascular Disease
Obesity- Type 2 Diabetes
Alcohol- Liver Disease, Impaired Brain Function
Exposure to carcinogens- Cancer
Smoking/Alcohol during pregnancy- Poor development of foetus
What is cancer?
Result of changes in DNA of cells that lead to uncontrolled growth and division resulting in formation of tumour
What are benign tumours?
Growth of abnormal cells, contained in one area and do not invade other parts of body
What are malignant tumours?
- Cancers
- Cells invade neighbouring tissues and spread to different parts of body via blood and lymphatic system to form secondary tumours
- More likely to disrupt functioning or organ as they invade healthy tissue
What are some lifestyle risk factors and which cancer do they link to?
Obesity- Bowel, Liver and Kidney
Smoking- Lung, Mouth, Throat and Stomach
UV Radiation- Skin
Viral Infection- Cervical, Liver
What are genetic risk factors for cancer?
- Faulty mismatch repair genes responsible for proofing DNA are more likely to develop bowel cancers
- Faulty BRCA genes for breast and ovarian cancer
What is the waxy cuticle?
Protective layer on top of leaf, prevents water from evaporating
What is the upper epidermis?
Thin and transparent to allow light to enter palisade mesophyll layer underneath
What is the palisade mesophyll?
Column shaped cells tightly packed with chloroplasts to absorb light, maximising photosynthesis
What is the spongy mesophyll?
Contains internal air spaces that increases the surface area to volume ratio for the diffusion of gases
What is the lower epidermis?
Layer that contains guard cells and stomata
What are guard cells?
Absorb and lose water to open and close stomata to allow CO₂ to diffuse in, O₂ to diffuse out
What is stomata?
- Where gas exchange takes place
- Opens during day, closes at night
- Found on underside of leaf to reduce water loss
What is the vascular bundle?
Contain xylem and phloem to transport substance to and from leaf
What is the xylem?
Transports water and minerals into leaf for mesophyll cells to use in photosynthesis and for transpiration from stomata
What is the phloem?
Transports sucrose and amino acids made from photosynthesising leaves to non-photosynthesising regions
What are some adaptations to the leaf?
- Large SA
- Thin
- Chlorophyll
- Stomata
- Air spaces
- Maximises the diffusion of CO₂
What are the two types of transport vessel in a plant?
Xylem + Phloem
What is the xylem composed of?
Hollow tubes strengthened by lignin adapted for transpiration stream
What are root hair cells?
- Single-celled extensions of epidermis cells in root
- Increase SA, increase rate of absorption of water by osmosis and mineral ions by active transport
Why does water enter root hair cells by osmosis?
Soil water has a higher water potential than cytoplasm of root hair cell
How can you identify the xylem or phloem from cross-section of a root?
Xylem is on the inside, phloem is on the outside
What is transpiration?
Loss of water vapour from plant leaves by evaporation of water at the surfaces of the mesophyll cells followed by diffusion of water vapour through the stomata
How is the xylem adapted?
- Lignin deposited in cell walls causing cells to die and become hollow
- Join end-to-end to form a continuous tube for water and mineral ions to travel through
- Strengthens plant to withstand high pressure of water movement
Describe the movement in the xylem.
Only takes place in one direction - roots to leaves
What are factors that affect rate pf transpiration?
- Air Movement
- Humidity
- Light Intensity
- Temperature
Describe how guard cells open and close stomata
- Unevenly distributed cellulose, inner wall (thick), outer wall (thin) to aid opening and closing
- When water availability is high, guard cells become turgid as a result of osmosis
- Stomata they surround open and air can circulate but water is lost via transpiration
- When water availability is low, guard cells lose water and become flaccid, pulling together and closing stomata
What is the direction of flow in phloem?
In all directions (from source to sink)
Are xylem cells living or dead?
Dead
Are phloem cells living or dead?
Living
What substances does xylem transport?
Water and mineral ions
What substances does phloem transport?
Sucrose and amino acids (cell sap)
What are sieve plates?
Pores in the end walls of phloem cells that allow substance flow between cells
What is a source in translocation?
Region where sugars are produced (typically photosynthesizing leaves)
What is a sink in translocation?
Region where sugars are used or stored (roots
How does translocation direction change in winter?
From storage organs to other parts of the plant for respiration
How does translocation direction change in spring?
From storage organs (roots) to growing areas of the plant
How does translocation direction change in summer?
From leaves (source) to roots and other storage organs (sinks)
What is cell sap?
The soluble products of photosynthesis - mainly sucrose and amino acids
What is the main sugar transported in phloem?
Sucrose (made of glucose and fructose)
How do companion cells relate to phloem?
They support sieve tube cells and assist in translocation
What’s a key structural difference between xylem and phloem cells?
Xylem consists of dead cells while phloem consists of living cells
What is the main difference between transpiration and translocation?
“Transpiration is water loss (via stomata), while translocation is nutrient transport (via phloem).”
How do the directions of flow differ in xylem and phloem?
“Xylem: Unidirectional (roots → leaves). Phloem: Bidirectional (moves sugars to where needed).”
What substances are transported in xylem vs. phloem?
“Xylem: Water + dissolved minerals. Phloem: Sugars (sucrose), amino acids, hormones.”
Is energy required for xylem or phloem transport?
“Xylem: Passive (no energy). Phloem: Active (requires ATP for loading/unloading sugars).”
How does structure differ between xylem and phloem?
“Xylem: Dead, hollow cells (tracheids/vessels). Phloem: Living sieve tubes + companion cells.”
What drives movement in xylem vs. phloem?
“Xylem: Transpiration pull + cohesion. Phloem: Pressure flow (bulk flow).”
Does transpiration involve gases or liquids?
“Transpiration: Water vapor (gas). Translocation: Liquid sap (sugars in water).”
Which process is linked to photosynthesis—transpiration or translocation?
“Translocation (moves sugars made in photosynthesis). Transpiration is unrelated.”
How do transpiration and translocation affect plant growth?
“Transpiration: Supports water/nutrient uptake. Translocation: Fuels growth/energy storage.”
Which vascular tissue is involved in transpiration?
“Xylem (transports water lost via transpiration).”
Which vascular tissue is involved in translocation?
“Phloem (transports sugars/organic compounds).”
Is root pressure relevant to xylem or phloem?
“Xylem (pushes water upward at night when transpiration is low).”
Can xylem transport occur without living cells?
“Yes (xylem cells are dead at maturity). Phloem requires living cells.”
What happens if xylem is damaged vs. phloem?
“Xylem damage: Wilting. Phloem damage: Sugar buildup, impaired growth.”
How do transpiration and translocation respond to environmental stress?
Transpiration: Slows in drought. Translocation: Adjusts based on plant needs.
