Exam Revision - From Notes Flashcards
The dependent variable is the variable we __________
measure
The independent variable is the variable we __________
change
A controlled variable is also known as the
Constant variable
Types of sampling
- Systematic sampling
- Random sampling
- Stratified sampling
- Judgement sampling
- Convenience sampling
Types of errors
- Personal error
- Systematic error
- Random error
Primary data is when you’re collecting _________ data
your
Raw data vs Transformed data
Raw data is as you write the results down in your logbook.
Transformed data is when you start graphing it or presenting it in tables.
Two types of variables
- Numerical
- Categorical
Two types of numerical data
- Discrete
- Continuous
Two types of categorical data
- Ordinal data
- Nominal data
Bar graphs are typically used to display ____________ data
Categorical and discrete
Line graphs and scatter plots display __________________ data
Continuous
A question to assess precision
are the results within the replicate treatments similar or different?
A question to assess accuracy
Are the recorded values similar or different from the true values?
A question to assess outliers
Are there any data points that stand out or do not follow the pattern?
Three approaches to bioethics
consequence based approach, rule/duty based approach, and virtues-based approach.
What is the aim of a consequence-based approach?
to maximise positive outcomes whilst minimising negative effects.
What is the aim of a rules/duty based approach?
To follow a set of rules and responsibilities, with less regard of the consequences as a result.
What is the aim of a virtues-based approach?
To emphasise the moral nature of the individual, and provide guidance as to the behaviours a morally good person would hope to achieve.
The five ethical concepts in Biology
integrity, justice, beneficence, nonmaleficence, and respect.
Integrity is the commitment to _____________-
Knowledge
Justice is the commitment to ________________
Fairness
Beneficence is the commitment to ____________
Maximising benefits
Nonmaleficence is the commitment to ____________________
Minimising harm
Respect is the commitment to __________________
Consideration
What are 8 qualities that all living things possess?
Movement
Respiration
Sensitivity
Growth
Reproduction
Equilibrium
Excretion
Nutrition.
What does cell theory state?
- All living things are made up of cells.
- Cells are the smallest and most basic units of life.
- All cells come from pre-existing cells.
What are the Six Kingdoms of life
Animalia, Archaea, Bacteria, Fungi, Plantae, and Protista
How do eukaryotic cells replicate?
Mitosis and meiosis
How do prokaryotic cells replicate?
binary fission
Differences between eukaryotic and prokaryotic cells.
Eukaryotic cells have membrane-bound organelles whilst prokaryotes do not
Eukaryotic cells have multiple linear strands of DNA packaged in chromosomes in the nucleus whilst prokaryotes have one circular chromosome and some additional plasmids.
What are the three domains of life?
- Archaea
- Bacteria
- Eukarya
What domains are prokaryotic, and which is eukaryotic?
Prokaryotic: Archaea and bacteria
Eukaryotes: Eukarya
What kingdoms can Eukarya be divided into?
Animalia, Fungi, Plantae, and Protista.
What is an organelle?
A cellular structure that performs specific functions
What is cytosol? What is cytoplasm?
Cytoplasm is everything inside the cell except the nucleus, whilst the cytosol is the internal liquid.
What does the nucleus store?
Genetic material
The nucleus is surrounded by a _______________________
double membrane
What does the nucleolus produce?
Ribosomes
What are ribosomes made up of?
Ribosomal RNA
Ribosomal RNA can be abbreviated to?
rRNA
Where are two places ribosomes can be found in the cell?
They can float freely in the cytoplasm or are attached to the rough ER
Ribosomes assemble the building blocks to build _______________
proteins
The Rough ER is coated with ___________________
ribosomes
What does the Rough ER do?
It synthesises and modifies proteins
Smooth ER are responsible for the production of _______________
lipids
The Golgi Apparatus is also known as the _________________
Golgi body
The Golgi Apparatus does what?
Packages and modifies proteins readying them for cell use or export
Lysosomes contain ________________________
Digestive enzymes
What do lysosomes do?
Break down cell waste and toxins.
What does the Mitochondria do?
the site of aerobic respiration cellular respiration and produces ATP.
Chloroplasts are the site of ___________________
photosynthesis
Vacuole is used for ________
storage
The vacuole helps maintain _____________ in ___________ cells.
structure, plant
What type of cells are the cell wall found?
Plant, bacterial, and fungal cells
Which organelles are not membrane bound?
Ribosomes, cell wall, and cytoskeleton
The folds of the inner membrane of the mitochondria are known as the
cristae
The space inside the inner membrane is known as the
Mitochondrial matrix
The word formula for aerobic cellular respiration is
glucose + oxygen = carbon dioxide + water + energy.
The chemical formula for aerobic cellular respiration is
C6H12O6 + 6O2 = 6CO2+ 6H2O + 36 ATP
What kind of cells can chloroplasts be found in?
Plant and algae cells
The chemical formula for photosynthesis is
6CO2 + 6H2O = C6H12O6 + 6O2
The word formula for photosynthesis is
Carbon Dioxide + Water = Glucose + Oxygen
What are some of the key differences between plant and animal cells.
The key differences between animal and plant cells is that plant cells have a cell wall whilst animal cells do not, chloroplasts are present in plant cells but not in animal cells, and vacuoles in animal cells are small and there can be many or none whilst plant cells tend to have one large vacuole.
What are the benefits of having small cells?
(1) The exchange of materials with the extracellular environment can occur efficiently (2) Distances to travel within the cell are smaller, so intracellular transport is faster.
What does the plasma membrane separate?
the intracellular environment to the extracellular environment
The main component of the phospholipid bilayer are
Phospholipids
What is the name of the arrangement of phospholipids?
The phospholipid bilayer
What are the two components of phospholipids
- Phosphate head
- Fatty acid tails
What is the phosphate head made up of?
Glycerol and phosphate group
What is the charge of the phosphate head?
Negatively charged
Is the phosphate head hydrophobic or hydrophilic?
Hydrophilic
Is the phosphate head polar or non polar?
Polar
What are the two fatty acid tails made up of?
Chains of Carbon and Hydrogen
What is the charge of the two fatty acid tails?
Uncharged
Are the two fatty acid tails hydrophobic or hydrophilic?
Hydrophobic
Are the two fatty acid tails polar or non polar?
Non polar
As phospholipids have both hydrophobic and hydrophilic parts they are ____________________ molecules
amphipathic
What are the names of the three types of proteins embedded in the plasma membrane?
- Integral proteins
- Transmembrane proteins
- Peripheral proteins
What are integral proteins?
proteins that are a permanent part of the membrane
What are transmembrane proteins?
integral proteins that span the entire bilayer
What are peripheral proteins?
are temporarily attached to the plasma membrane
What are the four functions/purposes of proteins in the plasma membrane?
- Transport
- Catalysis
- Communication
- Adhesion
Where is cholesterol in the plasma membrane?
Between the fatty acid tails
What are the two types of carbohydrates present in the membrane?
- Glycolipids
- Glycoproteins
What are glycolipids
Carbohydrates rooted to lipids
What are glycoproteins?
Carbohydrates rooted to proteins
What three functions do carbohydrates perform?
cell-cell communication, signaling, and adhesion
What does cholesterol regulate in the plasma membrane?
Fluidity
What 2 things does the fluid mosaic model dictate?
1) molecules that make up the membrane are not held static in one place and 2) many different types of molecules are embedded in the plasma membrane.
Active transport requires ________________
energy
What are the two types of active transport
- Protein mediated transport (or just “Active Transport”)
- Bulk transport
What are the two requirements for when a molecule needs to be transported against its concentration gradient?
- Energy
- Membrane proteins
How is bulk transport different from protein mediated transport?
Protein-mediated transport uses membrane proteins whilst bulk transport uses vesicles
What are the three steps of protein mediated transport?
- Binding
- Conformational change
- Release
What reaction occurs during conformational change to release energy?
ATP —> ADP + P
What are two types of bulk transport?
- Endocytosis
- Exocytosis
What is the difference between endocytosis and exocytosis?
Exocytosis is for molecules exiting the cell and endocytosis is for molecules entering the cell.
Steps of exocytosis
- Vesicular transport
- Fusion
- Release
Steps of endocytosis
- Fold
- Trap
- Bud
What is phagocytosis?
The endocytosis of solid materials - ‘cell eating’
What is pinocytosis?
The endocytosis of liquid materials - ‘cell drinking’
What are the purposes of cell replication?
1) Growth and development, 2) Maintenance and repair, 3) Reproduction
Prokaryotes replicate ex…….
ponentially
What is the process called through which prokaryotes replicate?
Binary fission
Binary fission is a form of ________________ reproduction
asexual
Steps of binary fission
- DNA replication
- Elongation
- Septum formation
- Cell division
What are the three stages of the eukaryotic cell cycle?
Interphase, mitosis, cytokinesis
What is the longest stage of eukaryotic cell division?
Interphase
Three stages of interphase
- G1
- S
- G2
What occurs during G1?
the volume of cytosol increases, proteins get synthesised, and organelles replicate
What occurs during the S phase?
the cell replicates its DNA by creating sister chromatids.
Sister chromatids are held together by a centromere
Why do cells go to the G0 stage?
As they are no longer required to replicate
What are the two types of cells that go to G0?
- Quiescent cells
- Terminally differentiated cells
Can quiescent cells and/or terminally differentiated cells re-enter the cell cycle?
Quiescent cells can re-enter
Terminally differentiated cells cannot
What happens in G2?
there is an increase in the volume of cytosol, and protein synthesis occurs.
What are the four stages of mitosis?
- Prophase
- Metaphase
- Anaphase
- Telophase
What occurs during prophase?
chromosomes condense, spindle fibres form, centrioles migrate to the poles of the cell, the nuclear membrane breaks down, and the nucleolus disappears.
What occurs during metaphase?
spindle fibres fully form, and chromosomes line up at the equator of the cell.
What occurs during anaphase?
the chromatids go to opposite ends of the cell.
What occurs during telophase?
Spindle fibres disintegrate, chromosomes decondense, nuclear membrane is formed, and two genetically identical nuclei get produced.
What occurs during cytokinesis?
cytoplasm divides and organelles evenly distribute themselves.
What is different between how animal and plant cells undergo cytokinesis?
In animal cells, during cytokinesis, a cleavage furrow develops which pinches the cell in half whilst in plant cells, a cell plate forms at the equator before the cell splits in two.
How many checkpoints has the cell cycle got?
3
What are the 3 checkpoints of the eukaryotic cell cycle?
- G1 checkpoint
- G2 checkpoint
- Metaphase checkpoint
What does the G1 checkpoint verify?
the cell has grown to the correct size, and has synthesised enough protein for DNA replication.
What does the G2 checkpoint verify?
The G2 checkpoint ensures that DNA has been replicated properly and that the cell has enough resources for mitosis
What does the metaphase checkpoint verify?
the cell checks the formation of the spindle fibres and if the chromosomes are in the right location.
What is apoptosis?
The controlled and systematic death of cells, programmed cell death
What are the two pathways of apoptosis?
- Mitochondrial pathway
- Death receptor pathway
Steps of the mitochondrial pathway
- Mitochondria detect cell malfunction
- Mitochondria release cytochrome c into the cytosol
- Caspase enzyme activated
- Apoptosis begins
Steps of the death receptor pathway
- Death receptor proteins recognise death signalling molecules
- molecules bind with the receptor causing the initiation of the caspase enzyme
- apoptosis is initiated
What is necrosis?
the unregulated and uncontrolled death of cells which causes cells to swell and burst.
What are the consequences to necrosis?
may lead to inflammation and damage to nearby cells and tissues.
Steps of apoptosis
- Activate of caspase enzyme
- digestion of cell contents, 3. cell shrinkage,
- membrane blebbing.
What occurs after apoptosis?
phagocytosis
What happens if the cell cycle is disrupted?
damaged cells will replicate exponentially leading to the development of cancer and tumours
What are the two categories of tumours?
benign tumours and malignant tumours
What is the difference between benign tumours and malignant tumours?
malignant tumours can invade nearby tissue and enter the blood spread and spread
Are benign or malignant tumours cancerous?
Malignant = cancerous
Benign = not cancerous
What are stem cells?
undifferentiated cells with the capacity to differentiate into specialised cells with a particular function.
What are two things a cell must have to be considered a stem cell?
1) be unspecialised
2) be capable of self-renewal
When a stem cell reproduces it produces…..
1) differentiated cell
2) another stem cell
What are totipotent cells?
Totipotent stem cells are stem cells with the greatest potency. They can differentiate into any stem cell type
What are pluripotent cells?
Pluripotent stem cells can differentiate into multiple cell types. They are less potent than totipotent cells but have a greater potency than multipotent cells
What are multipotent cells?
Multipotent cells can differentiate into a limited number of specialised cell types belonging to a specific organ or tissue. They are less potent than pluripotent cells but more potent than unipotent oligopotent cells.
What does ectoderm differentiate into?
neurons, skin cells, and pigment cells
What does mesoderm differentiate into?
skeletal muscle, smooth muscle, cardiac muscle, red blood cells, and bone cells.
What does endoderm differentiate into?
stomach cells, pancreatic cells, and liver cells
A zygote is totipotent/pluripotent/multipotent?
totipotent
A blastocyst is totipotent/pluripotent/multipotent
pluripotent
Ectoderm, mesoderm, and endoderm are totipotent/pluripotent/multipotent
Multipotent
What are the five different levels of complexity?
- Cells
- Tissues
- Organs
- Systems
- Organisms
The two organ systems of vascular plants are
- Root system
- Shoot system
Four major tissue types are:
epithelial, connective, muscle, nervous
Name the three types of muscle tissue. State if they are voluntary or involuntary
Skeletal muscle tissue (voluntary control), cardiac muscle tissue (involuntary control), and smooth muscle tissue (involuntary control).
Two types of vascular tissue
Xylem and phloem
Xylem tissue
- One way flow
- Water and minerals
Phloem tissue
- Two way flow
- Water and food
What are the stomata?
are in the leaves and control evaporation
What are mesophyll?
the ground tissue of the leaf specialised for photosynthesis
Four ways in which water moves from roots to leaves in Xylem vessels:
1) Osmosis, 2) Adhesion, 3) Transpiration, 4) Cohesion
What is transpiration?
the pressure of evaporation to raise water up from the roots towards the plant.
What does the digestive system do?
The digestive system breaks down food
Two methods of food digestion
Physical/mechanical digestion and chemical digestion
Four steps of digestion
ingestion, digestion, absorption, and elimination/egestion
What does the oral cavity do?
beginning of the digestive system and the site of ingestion. Teeth mechanically break down food and saliva chemically break down others.
What do the salivary glands do?
oroduce saliva into the mouth and oesophagus
What does the oesophagus do?
A hollow tube connecting the oral cavity to the stomach in which food flows down after being swallowed. The movement of food is aided by muscular contractions: peristalsis.
What does the stomach do?
Food is churned by muscular movements, and digestive juices break down food. Peristalsis also occurs here and digested food leaves the stomach as chyme
What are the 3 roles of the liver?
- The site of bile production 2. filtration of blood,
- detoxifying chemicals.
What does the gallbladder do?
Bile is stored here before being released into the small intestine
What does the pancreas do?
Produces digestive enzymes, and regulates blood sugar levels
What does the small intestine do?
Absorb nutrients and deliver them to the circulatory system and continue breaking down food
What are the three sections of the small intestine?
duodenum, the jejunum, and the ileum
How is the small intestine adapted for absorption?
as villi and microvilli provide a very large surface area
What does the large intestine do?
Final absorption of water, minerals, and vitamins
Three sections of the Large Intestine
Cecum, Colon, and Rectum
What does the rectum do?
Area of the large intestine that stores faeces
What does the anus do?
The end of the digestive tract, faeces are expelled
What is a tissue and how does it differ between organs?
A tissue is a group of similar cells that work together. Each organ has its own unique combination of tissues.
What are the 2 systems of a plant?
Plants have root and shoot systems. The root system is underground, and the shoot system is aboveground.
What do the xylem and phloem transport and in what direction?
Xylem transports water and minerals upward, while phloem transports food (like sugars) both upward and downward.
What are the 2 pathways of water and nutrient absorption in a plant?
Plants have two pathways for water and nutrient absorption: the extracellular pathway (through spaces outside cells) and the cytoplasmic pathway (through the cell cytoplasm).
What is the process of water evaporating from leaves called?
Transpiration
What controls the stoma?
Guard cells
What is the main role of the digestive system?
The main role of the digestive system is to break down food into smaller pieces and absorb nutrients
What is the difference between chemical and physical digestion?
Chemical digestion involves the breakdown of food using enzymes and acids, while physical digestion involves the mechanical breakdown of food through actions like chewing and churning.
What is the pathway of food? (Ingestion->Elimination)
The pathway of food starts with ingestion (eating), followed by digestion in the stomach and small intestine, absorption of nutrients in the small intestine, and elimination of waste through the large intestine and rectum.
What does the liver do?
The liver performs various functions, including filtering toxins from the blood, producing bile to aid in fat digestion, storing nutrients, and regulating blood sugar levels.
What is the pancreas responsible for?
The pancreas produces enzymes that help break down carbohydrates, proteins, and fats in the small intestine. It also produces insulin and glucagon, which are involved in regulating blood sugar levels.
Name the types of digestive enzymes and what they break down.
Some types of digestive enzymes include amylase (breaks down carbohydrates), protease (breaks down proteins), and lipase (breaks down fats).
What does the large intestine do?
The large intestine absorbs water and electrolytes from undigested food, forming feces and facilitating the elimination of waste from the body.
Why does the digestive tracts length differ from species to species?
Digestive tract length varies across species based on their diets. Plant-eating animals tend to have longer digestive tracts to break down complex plant materials, while meat-eating animals have shorter tracts as meat is easier to digest. The length is adapted to suit the specific dietary needs of each species.
What does the excretory system do?
The excretory system helps our body get rid of waste and toxins.
How does this regulate the osmolality of the body? (excretory system)
The excretory system helps maintain the right balance of water and salts in our body. It regulates the osmolality by adjusting the amount of water and salts we keep or get rid of.
How is excess protein excreted?
When there is too much protein, our body breaks it down and removes the waste products in urine.
What is the difference between ureter and urethra?
The ureter carries urine from the kidneys to the bladder, while the urethra carries urine out of the body.
What does the nephron do?
The nephron is a tiny part of the kidney that helps filter waste and maintain the right balance of substances in our body.
How does the glomerulus and Bowman’s capsule operate?
The glomerulus is like a filter in the kidney that catches waste and small molecules from the blood. The Bowman’s capsule collects the filtered waste and sends it on its way to become urine.
Describe the overall process of the nephron.
In the nephron, blood enters the glomerulus, where waste products are filtered. Then it goes through the tubules where important substances are reabsorbed into the bloodstream. Finally, the remains become urine
How is water reabsorbed? (excretory system)
Osmosis
What does ADH and renin do and how?
ADH tells the kidneys to absorb more water by reducing urine production.
Renin is released by the kidneys when blood pressure is too low and triggers reactions.
What does the endocrine system do?
The endocrine system releases hormones that help control and regulate different functions in our body.
How is the nervous system different from the endocrine system?
Endocrine system uses hormones, nervous system uses electrical signals
How do hormones only affect specific cells?
It only binds to cells with that specific receptor
What is an endocrine gland vs exocrine gland?
An endocrine gland releases hormones directly into the bloodstream, while an exocrine gland releases substances
List 3 endocrine glands and what they secrete.
Pituitary gland: Growth hormone
Thyroid gland: Thyroid hormones
Adrenal glands: Adrenaline
What is one hormone the hypothalamus secretes and how does it work?
Oxytocin - helps with childbirth and bonding
What response does adrenaline stimulate?
Increases heart rate, energy availability, and blood pressure
How is water loss/transpiration regulated in plant cells?
Through the opening and closing for the stomata
What happens if guard cells become turgid?
Stomata open
What are the key tissues in vascular plants?
Xylem and Phloem
How is water taken up by plants?
Plants take up water through their roots. Special structures called root hairs absorb water from the soil and it travels through the root system.
How does water move through plants?
Water moves through plants from the roots to the leaves through a process called transpiration. It is pulled up through the xylem tubes, creating a continuous flow of water and nutrients.
How is water lost from plants?
Water is lost from plants through small openings called stomata
What is homeostasis?
Homeostasis is the body’s ability to maintain a stable internal environment despite external changes.
What are some parameters that affect the functioning of cells?
- Temperature
- pH
Describe the stimulus response model
The stimulus-response model describes how organisms respond to changes in their environment. It involves several components:
Stimulus: A change in the environment that triggers a response.
Receptor: A structure or cell that detects the stimulus.
Modulator: The brain or control center that assesses the information and determines the appropriate response.
Effector: The part of the organism that carries out the response.
Response: The action or change that occurs as a result of the stimulus.
Describe positive feedback systems
In a positive feedback system, the response amplifies or reinforces the original stimulus
Describe negative feedback systems
In a negative feedback system, the response opposes the initial change, bringing the body back to its normal state. It helps maintain stability and balance in the body.
Heat transfer occurs in the body via four methods:
- Conduction
- Convection
- Evaporation
- Radiation
How does heat transfer occur in conduction?
Through physical contact with another object
How does heat transfer occur under convection?
Movement of liquid or a gas
How does heat transfer occur under evaporation?
Conversion of liquid water into gas
How does heat transfer occur under radiation?
Electromagnetic waves
What is the receptor for detecting changes in temperature?
Thermoreceptors
What is the receptor that detects painful stimuli?
Nociceptors
What is the receptor that detects changes in pressure
Baroreceptors
What is the receptor that detects changes in chemical concentration?
Chemoreceptors
What is the receptor that detects changes in light?
Photoreceptors
Endotherms generate most of their heat ________________
internally
Ectotherms generate most of their heat _______________________
from environmental sources
Negative feedback loop of heat regulation.
Stimulus - change in internal/external temperature
Receptor - Thermoreceptors
Modulator - Hypothalamus
Effector - Cells and tissues
Response - Change in temperature
Where do we get glucose from?
Carbohydrates
Steps of glucose from food
- The digestive system breaks down the glucose from food into a variety of enzymes
- Glucose is absorbed by the small intestine
- Glucose is released into the bloodstream
- Glucose travels around the body to different cells
- Once in cells, respiration takes place
- ATP is produced
What is the name of the process that converts glucagon into glucose
Glycogenolysis
What does glucose travel in across the body?
Blood plasma
Q
What happens when a person has too much Glucose (name)
hyperglycaemic
What happens when a person has too little Glucose (name)
hypoglycaemic
How does our body maintain the right level of glucose?
Homeostasis
Stimulus in homeostasis of glucose
Blood glucose levels
Receptor in homeostasis of glucose
The pancreas (Islets of
Langerhans)
Modulator in homeostasis of glucose
The pancreas (Islets of Langerhans)
Response of homeostasis of glucose
increase or
decrease in
blood sugar
levels
When an islet of Langerhans detects a blood glucose level above around 5 mmol/L, what happens?
Beta cells release insulin
Two different pathways of insulin (glucose homeostasis)
Skeletal muscle and fat cells absorb more glucose from the blood
Liver cells are stimulated to convert more glucose into glycogen
Two different effectors used to decrease glucose levels
Liver cells
Skeletal, muscle, and fat cells
Response of liver cells effector (homeostasis of glucose)
increased
conversion
of glucose to
glycogen
Response of “Skeletal, muscle, and fat cells” effector (homeostasis of glucose)
insertion of glucose
transporters into
cell membrane
List what homeostasis does when blood sugar is too low
Stimulus: Blood glucose levels
Receptor: Islets of
Langerhans
Moderator: islets of Langerhans
Effector: Liver cells
Response: Breakdown of glycogen into glucose, released into the blood stream
What is homeostasis?
A process that maintains the internal environment of an organism so that systems can function appropriately
5 things that effect function of cells
- Temperature
- pH acidity level
- Blood sugar levels
- Sodium and Potassium concentration
- Fluid balance
What is the stimulus-response model?
Outlines how the changes in external and internal environments can influence an organisms functions
The 5 components of the stimulus-response model
- Stimulus
- Receptor
- Modulator
- Effecter
- Response
Describe the Stimulus component of the stimulus-response model
The change in the internal and/or external environment of the organism
Describe the Receptor component of the stimulus-response model
The receptor detects the stimulus and transfers its knowledge to the Modulator
Describe the Modulator component of the stimulus-response model
Information detected via the receptors are sent to the Modulator. The Modulator compares this information to the ideal state for the organism and then releases molecules to alter the functioning of an effector
Describe the Effecter component of the stimulus-response mode
A molecule, cell, or hormone that responds to the signal of the Modulator and produces a response
Describe the Response component of the stimulus-response model
The Effecter initiates the response. The response can be any change to react to the stimulus.
Thermoreceptors
Detect changes in temperature
Nociceptors
Detect painful stimuli
Baroreceptors
Detect changes in pressure
Chemoreceptors
Detect changes in chemical concentration
Photoreceptors
Detect changes in light
When does the positive feedback system occur?
When the response increases the initial stimulus
When does the negative feedback system occur?
When the response counters the stimulus
Three steps of cellular signaling
- Reception
- Transduction
- Response
Describe the reception part of cellular signalling
The detection of the stimulus and then converting this into an electrical, chemical, or mechanical signal
Describe the Transduction part of cellular signalling
The transmission of signal during cellular signaling. Can involve sending a signal between organisms, across the body, to a neighboring cell, or back to the original receptor cell
Describe the Response part of cellular signalling
The change in the function of the target cell, organ, or organism
The four methods of heat transfer
1 - Conduction
2 - Convection
3 - Evaporation
4 - Radiation
Explain conduction
The transfer of heat through physical contact
Explain convection
Transfer heat via movement of a liquid or gas between areas of different temperature
Explain evaporation
The loss of heat through the conversion of water from liquid into gas form.
Explain radiation
The transfer of heat through electromagnetic waves
How does thermal regulation occur?
Through a negative feedback stimulus-response system
In terms of thermoregulation, species can be divided into two different groups:
Endotherms
Ectotherms
Endotherms are also known as
Warm blooded species
How do endotherms generate the majority of their heat:
Through metabolic processes
Ectotherms are also known as
Cold blooded species
How do ectotherms generate the majority of their heat:
Through environmental sources
In the case of thermoregulation, the Modulator is:
Hypothalamus
What is the preferred core body temperature of the body?
37 degrees celcius
Effecters of responses in thermoregulation when it is too hot (5)
Effector - Sweat glands
Response - Sweating
Effector - Small blood vessels in skin
Response - Dilation of arterioles
Effector - Cerebral cortex
Response - Change in behavior
Effector - Arrector pili muscles
Response - Flattening of hair
Effector - Cells
Response - Decrease in metabolic rate
Effecters of responses in thermoregulation when it is too hot (5)
Effector - Sweat glands
Response - Sweating
Effector - Small blood vessels in skin
Response - Dilation of arterioles
Effector - Cerebral cortex
Response - Change in behavior
Effector - Arrector pili muscles
Response - Flattening of hair
Effector - Cells
Response - Decrease in metabolic rate
Effecters and responses in thermoregulation when it is too cool (6)
Effector - Skeletal muscles
Response - Shivering
Effector - Small blood vessels in skin
Response - Constriction of arterioles
Effector - Cerebral cortex
Response - Change in regulation
Effector - Arrector pili muscles
Response - Lifting of hair
Effector - Cells
Response - Increase in metabolic rate
Effector - Brown fat
Response - Burning of triglycerides
Stimulus in thermoregulation
change in
internal body
and/or
environmental
temperature
Receptor in thermoregulation
Thermoreceptor
Modulator in thermoregulation
Hypothalamus
Effector in thermoregulation
Variety of cells and tissues
Response in thermoregulation
change that
alters heat
transfer in body
Water is regulated through a process called ……………….
osmoregulation
Stimulus in osmoregulation
Change in water volume
Receptors in osmoregulation
- Baroreceptors
- Osmoreceptors
Modulators in osmoregulation
- Cells in kidney
- The hypothalamus and pituitary gland
Effectors in osmoregulation
- In hypothalamus
- Cells in distal convoluted tubule and collecting duct
Response in osmoregulation
Altercation of reabsorption of water
Name a malfunction in homeostasis.
How does this malfunction effect the homeostatic mechanisms of the body?
Type 1 diabetes is a malfunction in homeostasis. In this condition, the body’s immune system mistakenly attacks and destroys the insulin-producing cells in the pancreas. As a result, the body lacks insulin, which disrupts the normal homeostatic mechanisms responsible for regulating blood sugar levels
What is the basic structural feature of all life on Earth?
Cells
What are prokaryotic cells?
Prokaryotic cells are simple cells that lack a nucleus and other membrane-bound organelles. They are typically smaller and less complex compared to eukaryotic cells.
What are eukaryotic cells?
Eukaryotic cells are more complex cells that contain a nucleus and various membrane-bound organelles. They are larger and have a more organized internal structure compared to prokaryotic cells.
What are the key differences between prokaryotic and eukaryotic cells?
Prokaryotic cells are smaller, simpler cells without a nucleus or membrane-bound organelles, while eukaryotic cells are larger, more complex cells with a nucleus and various membrane-bound organelles.
What is surface area to volume ratio?
Surface area to volume ratio compares the object’s surface area to its volume.
How does SA: V impact cell size?
The surface area to volume ratio (SA:V) affects cell size by determining the efficiency of nutrient exchange and waste removal. Cells aim to maintain an optimal size to ensure sufficient surface area for these processes to occur effectively.
How does SA:V influence the rate of diffusion?
Higher surface area to volume ratio (SA:V) speeds up diffusion, while lower SA:V ratio slows it down.
What is the difference between plant and animal cells?
Plant cells have a cell wall and chloroplasts, while animal cells do not possess a cell wall and lack chloroplasts.
What are the key organelles for both plant and animal cells?
The key organelles in plant and animal cells include the nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, and lysosomes.
What do mitochondria do in plant and animal cells
Mitochondria are responsible for producing energy in both plant and animal cells through a process called cellular respiration. They convert nutrients into adenosine triphosphate (ATP), the primary energy source for cellular activities.
What do chloroplasts do in plant cells?
Chloroplasts are responsible for photosynthesis in plant cells.
What is the structure of the plasma membrane?
The plasma membrane has a phospholipid bilayer structure. It consists of two layers of phospholipid molecules, with hydrophilic (water-loving) heads facing outward and hydrophobic (water-repelling) tails facing inward. Embedded within the phospholipid bilayer are various proteins that have different functions, such as transport, communication, and cell adhesion.
What is facilitated diffusion?
Facilitated diffusion is the passive transport of specific molecules across the cell membrane using transport proteins, without requiring energy.
What is active transport?
Active transport is the energy-requiring process by which molecules or ions are transported against their concentration gradient across the cell membrane.
What is the difference between hydrophilic and hydrophobic substances?
Hydrophilic substances are attracted to water and have an affinity for it, while hydrophobic substances repel water and do not easily mix or dissolve in it.
What is osmosis?
Osmosis is the passive movement of water molecules across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.
Describe the steps of binary fission?
DNA Replication
Elongation
Septum formation
Cell Division
Why is binary fission asexual reproduction?
Binary fission is considered a form of asexual reproduction because it involves the division of a single parent cell into two daughter cells, without the involvement of gametes or the fusion of genetic material from two different individuals.
What is apoptosis?
Programmed cell death
What role do malfunctions in apoptosis play in the development of cancer?
Malfunctions in apoptosis can disrupt the normal process of eliminating damaged or abnormal cells, leading to the accumulation of such cells and the development of cancer.
What are distinguishing characteristics of cancer cells?
Distinguishing characteristics of cancer cells include uncontrolled and abnormal cell growth, evasion of cell death mechanisms, ability to invade surrounding tissues, potential to metastasize (spread to other parts of the body), and genetic instability.
What are the properties of stem cells which enable cell and tissue renewal?
The properties of stem cells that enable cell and tissue renewal include self-renewal (the ability to divide and generate identical copies of themselves) and differentiation (the potential to develop into specialized cell types in the body).
How do stem cells facilitate cell differentiation and specialization?
Stem cells facilitate cell differentiation and specialization by dividing into one stem cell and one specialized cell, allowing for the generation of different cell types in the body.
What is a tissue and how does it differ from an organ or system?
A tissue is a group of cells with similar functions, while an organ is made up of different tissues working together, and a system consists of organs that collaborate to perform specific functions in the body.
What are the key tissues in vascular plants?
- Xylem
- Phloem
How is water taken up by plants?
Water is primarily taken up by plants through their roots, where it enters through osmosis and then moves upward through the xylem tissue.
How does water move through plants?
Water moves through plants via transpiration, as water evaporates from the leaves, creating a suction force that pulls water up through the xylem vessels.
How is water lost from plants?
Water is lost from plants through transpiration, as it evaporates from the surfaces of leaves and stems.
How do animal cells specialize and form tissues, organs, and systems?
Animal cells specialize and form tissues, organs, and systems through cell differentiation, where cells acquire specific structures and functions during development, enabling the organization and coordination of specialized functions in the body.
Describe the functions of the digestive systems of animals?
the digestive system of animals is responsible for breaking down food into smaller molecules, absorbing nutrients, and eliminating waste materials from the body.
What is the role of the endocrine system in animals?
The endocrine system in animals is responsible for producing and releasing hormones that regulate various bodily functions, including growth, metabolism, reproduction, and response to stress.
Explain the functions of the excretory system in animals.
The excretory system in animals is responsible for removing waste products, such as excess water, salts, and metabolic waste (e.g., urea), from the body, maintaining proper fluid balance, and regulating the concentration of ions and pH levels in the bloodstream.
How do animal cells communicate to perform specific functions in the tissue?
Animal cells communicate to perform specific functions in the tissue through a process called cell signaling, where cells release chemical signals, such as hormones or neurotransmitters, that bind to specific receptors on target cells, triggering a response and coordinating their activities.
How do vascular plants regulate water?
Vascular plants regulate water through transpiration and the controlled opening and closing of stomata to manage water loss and maintain proper water balance within the plant.
What is the role of water balance in vascular plants?
The role of water balance in vascular plants is to ensure the proper hydration and functioning of cells, facilitate the transport of nutrients and minerals, maintain turgidity and structural support, and support various physiological processes essential for growth and survival.
How is body temperature regulated?
Body temperature is regulated through a process called thermoregulation, where the body maintains a relatively constant internal temperature through mechanisms such as sweating, shivering, vasodilation (expanding blood vessels) and vasoconstriction (contracting blood vessels), adjusting metabolic rate, and behavioral adaptations to respond to changes in external temperature.
What are the mechanisms of blood glucose regulation?
The mechanisms of blood glucose regulation involve the actions of insulin, which lowers blood glucose levels, and glucagon, which raises blood glucose levels, ensuring a stable balance of glucose for cellular energy needs.
How do animals maintain water balance?
Animals maintain water balance through osmoregulation, a process that involves controlling the concentration of water and solutes within their bodies, adjusting water intake and excretion, and adapting specialized structures and mechanisms to maintain proper internal osmotic conditions.
What are stimulus-response models?
Stimulus-response models are frameworks that explain how organisms or systems react and adapt to different stimuli in their environment through specific responses.
Explain the concept of feedback loops
Feedback loops are regulatory mechanisms that monitor and adjust a system based on its output, either amplifying or counteracting the initial stimulus to maintain stability and balance.
What organ structures are involved in homeostatic regulation?
Organ structures involved in homeostatic regulation include the hypothalamus, which acts as a control center, various endocrine glands that produce hormones, and organ systems such as the circulatory and nervous systems that help coordinate and carry out the necessary responses to maintain internal balance.
What does ADH stand for?
Antidiuretic hormone
Where is ADH produced?
ADH is produced in the hypothalamus of the brain and released from the posterior pituitary gland.
What is the main function of ADH?
The main function of ADH is to regulate water balance in the body by controlling the reabsorption of water by the kidneys.
What triggers the release of ADH?
The release of ADH is triggered by an increase in blood osmolality or a decrease in blood volume, which are detected by the hypothalamus.
How does ADH act on the kidneys?
ADH acts on the kidneys by increasing the permeability of the collecting ducts, allowing more water to be reabsorbed into the bloodstream.
What is the result of increased ADH release?
Increased ADH release leads to increased water reabsorption, which helps concentrate urine and reduce water loss from the body.
What happens when ADH levels are low?
When ADH levels are low, less water is reabsorbed by the kidneys, leading to increased urine output and potential dehydration.
What conditions can disrupt ADH regulation?
Conditions such as diabetes insipidus, where ADH production or response is impaired, can disrupt ADH regulation and result in excessive urine production and thirst
How is ADH release regulated?
ADH release is regulated by negative feedback, where high blood osmolality or low blood volume triggers ADH release, and as these conditions normalize, ADH release is inhibited.
What other factors can influence ADH release?
Factors such as stress, alcohol consumption, and certain medications can also influence ADH release and water balance in the body.
