B1, B2 & B3 test (oct 24th) Flashcards
What are the seven characteristics of life?
Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition
Movement definition
an action by an organism or part of an organism causing a change of position or place.
Respiration definition
The chemical reactions in cells that break down nutrient molecules and release energy for metabolism
What is respiration not the same as
breathing
what is breathing
the movement of air in and out of the lungs.
Sensitivity definition
The ability to detect or sense stimuli in the internal or external environment and to make appropriate responses
Growth
A permanent increase in size and dry mass by an increase in cell number or cell size or both
Reproduction definition
The processes that make more of the same kind of organism
Excretion definition
The process by which an organism removes waste products of metabolism, toxic substances, and excess materials from its body to maintain homeostasis.
what is metabolism
All the chemical reactions in the cells of an organism, including respiration.
Nutrition definition
The taking in of materials for energy, growth and development
What is an example of movement
A plant’s leaves move towards light, ensuring it gets enough sunlight for photosynthesis.
What is an example of respiration
Humans break down glucose and oxygen in cells to produce energy, water, and carbon dioxide.
What is an example of sensitivity
A rabbit detects danger through its sense of hearing and quickly runs away, responding to the external stimulus.
What is an example of growth
A caterpillar grows by shedding its exoskeleton (molting) as it increases in size before becoming a butterfly.
What is an example of reproduction
pollination; where pollen is transferred to the stigma, leading to fertilization and the development of seeds.
What is an example of excretion
A fish excretes ammonia directly into the water through its gills
What is an example of nutrition
A lion hunts and consumes prey, obtaining the necessary nutrients for energy, growth, and repair.
What is a cell and what happens within cells
Basic units of life- all of the characteristics of life happen in them
Word equation for respiration
Glucose + oxygen -> Carbon Dioxide + water
How would you test respiration
Aim: Demonstrate carbon dioxide (CO₂) production during respiration.
Materials: Limewater, person or organism exhaling.
Method:
Exhale into a container of limewater.
Observe if the limewater turns cloudy, indicating the presence of CO₂.
Variables:
Independent: Exhalation into limewater.
Dependent: Limewater turning cloudy (CO₂ detection).
Control: Fresh limewater, same exhalation method.
Expected Results: Limewater turns cloudy, confirming CO₂ production during respiration.
How would you test Growth
Aim: Investigate how light affects plant growth.
Materials: Seeds, soil, water, ruler, 2 pots, light source.
Method:
Plant seeds in two pots, place one in sunlight (Pot A) and one in darkness (Pot B).
Water both equally, measure plant height daily for 10 days.
Variables:
Independent: Light exposure.
Dependent: Plant height.Control: Water, soil, temperature, seed type.
Expected Results: Plants in sunlight (Pot A) grow taller, showing light is essential for growth.
How would you test Sensitivity
Aim: Observe how plants respond to stimuli (light).
Materials: Potted plant, light source.
Method:
Place plant near a light source.
Observe plant’s growth direction over several days.
Variables:
Independent: Direction of light.
Dependent: Direction of plant growth.
Control: Water, temperature, plant type.
Expected Results: Plant bends toward light, showing sensitivity to environmental stimuli.
How would you test Excretion
Aim: Demonstrate the removal of carbon dioxide (CO₂) through excretion.
Materials: Limewater, person exhaling.
Method:
Exhale into a container of limewater.
Observe if the limewater turns cloudy, indicating the presence of CO₂.
Variables:
Independent: Exhalation into limewater.
Dependent: Limewater turning cloudy (CO₂ detection).
Control: Fresh limewater, same exhalation method.
Expected Results: Limewater turns cloudy, showing CO₂ is excreted during respiration.
Why is dry mass used to measure growth?
because it provides a more accurate reflection of the actual biomass of an organism by eliminating the weight of water, which can fluctuate and affect measurements.
plants cannot move about as animals can. does that mean animals are more alive than plants?
No, animals are not more “alive” than plants; both are equally alive but exhibit different adaptations for survival. Both of them carry out all life processes in different ways
During the winter, an oak tree will lose its leaves and not grow. Is it still alive during this time? explain
the oak tree remains alive during winter by slowing its metabolic processes and adapting to survive until the conditions improve. It is still alive.
What do all living organisms contain
cells
ATP stands for..
adenosine triphosphate
What is the formula to calculate the actual size of a specimen using magnification?
Actual size = Image size ÷ Magnification
If an image of a cell is 150 mm and the magnification is 600x, what is the actual size of the cell in micrometers?
Actual size = 150 mm ÷ 600 = 0.25 mm = 250 µm
How do plant cells differ from animal cells in terms of structure?
Plant cells have a cell wall, chloroplasts, and a large central vacuole, while animal cells do not.
What are the three steps to determine magnification
- use.a ruler to measure the scale bar in mm (image size)
- convert mm to the unit on the scale bar (real size)
- divide the scale bar length by the actual size.
what is magnification written as
__X e.g 400X
How many micrometers are in a millimeter?
1 millimeter (mm) = 1,000 micrometers (µm)
How many nanometers are in a micrometer?
1 micrometer (µm) = 1,000 nanometers (nm)
How many millimeters are in 5,000 micrometers?
5mm
What are examples of specialised cells
cilia cells, root hair cells, sperm cells etc.
Function of ciliated cells (practice drawing it!)
facilitates the movement of mucus in the trachea and bronchi to be swallowed. They are also found in fallopian tubes and nasal passage
Protects lungs from pathogens
Structure of ciliated cells
-hair like projections capable of moving in a coordinated sweeping motion
-Columnar shaped, packed closely tg
-close to mucus producing goblet cells
Function of Palisade Mesophyll cells (practice drawing it!)
Main site of photosynthesis
Structure of palisade mesophyll cells
- found in the upper part of the leaf (close to the surface)
-Contains many chloroplasts
-Columnar shape, packed closely together, allows for more cells
Function of red blood cells (practice drawing it!)
transport of oxygen to cells
Structure of red blood cells
- no nucleus (makes room for maximum oxygen)
-contains haemoglobin (protein)- helps transporting oxygen
-biconcave shape (allows smooth diffusion process through the body’s capillaries)
Function of root hair cells (practice drawing it!)
absorption of water and minerals
Structure of root hair cells
-elongated shape (increases surface area)
-many mitochondria (provides energy for active transport of solutes from soil)
-anchors the plant to the soil
Function of sperm cells (practice drawing it!)
reproduction
Structure of sperm cells
-relatively small (compared to egg cell)
-streamlined shape for enhanced mobility
-contains many mitochondria to provide energy for the movement of the flagellum
-contains enzymes in the Acrosome which digest a hole in the egg cell membrane
-haploid- contains half the number of chromosomes
Function of egg cells (practice drawing it!)
Reproduction
Structure of egg cells
- large (does not need to travel a lot also it needs to carry a lot of nutrients)
- cytoplasm contains nutrients for energy during cell division
function of neurons
transfer electrical signals
Function of bacterial cells
-cell growth
-metabolism
-decomposition
What are the different organelles
Nucleus, mitochondria, cytoplasm chloroplasts, ribosomes and cell membranes
What is the function of a nucleus
Contains genetic material (DNA) and controls cell activities, including growth and reproduction.
What is the function of ribosomes
Site of protein synthesis; can be free in the cytoplasm or attached to the endoplasmic reticulum.
What is the function of chloroplasts
Site of photosynthesis; converts light energy into chemical energy (glucose).
What is the function of cytoplasm
organelles are suspended; site of many metabolic reactions and provides structure to the cell.
What is the function of cell membrane
Regulates the movement of substances in and out of the cell; provides protection and structure. (partially permeable)
structure of bacteria (what does it have)
-plasmid
-gene replicating DNA
-ribosomes
-Pili
-Flagellum
-Cell wall
-Cell membrane
-Cytoplasm
What are eukaryotic cells
Eukaryotic cells are complex cells that contain a nucleus and membrane-bound organelles, allowing for organization of cellular functions.
What are prokaryotic cells
Prokaryotic cells are simple and found in unicellular organisms that lack a nucleus and membrane-bound organelles, with their genetic material floating freely in the cytoplasm.
Examples of EK cells
Animal, Plant, Fungal cells
Examples of PK cells
Bacterial cells
Similarities and differences between PK and Ek cells
Similarities:
-Surrounded by cell membrane
-Ribosomes
-DNA
-Cytoplasm
Differences:
EK
-Multicellular (mostly)
-Membrane bound organelles
-Have nucleus
PK
-No membrane bound ogranelles
-Unicellular
-No nucleus
-DNA floats freely in cytoplasm
Name the part of a plant cell that contains cell sap
vacuole
Name the part of a plant cell that stops the cell swelling if it takes in water
cell wall
What organelle is essential for diffusion and the exchange of materials
cell membrane
Whats one quality of the cell membrane
It is selectively permeable- It controls the type of substance that enters the cell and the time at which it does so
What is the cell membrane composed of
The phospholipid bilayer with embedded proteins
What does the protein allow
larger molecules that cant’t pass through the phospholipids to pass through different protein channels
What are types of cellular transport
-Passive transport (does not require ATP)
-Diffusion
-Osmosis
-Active transport (requires ATP)
What is diffusion
The movement of molecules from an area of high concentration to low concentration until it reaches equilibrium
Characteristics of diffusion
-Passive process (no energy needed)
-Follows concentration gradient
-continues until equilibrium is reached
Biological examples of diffusion
-oxygen moving from lungs to bloodstream
-CO2 moving from cells to bloodstream
concentration gradient definition
A difference in the concentration of a substance between to areas
Equilibrium
When particles are distributed evenly and are the same number in relation to two areas
Simple diffusion VS facilitated diffusion
Simple diffusion:
-direct movement through phospholipid bilayer
-for small non-polar molecules (e.g O2 & CO2)
Facilitated diffusion:
-Uses protein channels or carriers
-For larger, polar molecules
Factors affecting diffusion rate
-Concentration gradient
-Temperature
-Particle size
-Distance
What is osmosis
Diffusion of WATER across a selectively permeable membrane
What is water potential
Water concentration
What happens in osmosis
Water molecules move from a high water potential to a low water potential.
What are solutes
particles being dissolved
What are solvents
liquids that contain solutes
Tonicity
Relative solute concentration
Hypotonic
lower solute concentration outside of cell
Isotonic
equal solute concentration
Hypertonic
higher solute concentration outside of cell
What occurs when a cell is placed in an isotonic solution?
In an isotonic solution, there is no net movement of water, and the cell maintains its shape.
What happens to a cell placed in a hypertonic solution?
In a hypertonic solution, water leaves the cell, causing it to shrink (crenate).
What happens to a cell placed in a hypotonic solution?
In a hypotonic solution, water enters the cell, causing it to swell and potentially burst (lyse).
importance of movement in animals
helps in the effective functioning of digestion, metabolism, and immune response.
importance of movement in plants
phototropism- the movement of plant leaves towards sunlight to maximise photosynthesis
