B1 Flashcards
What are the 7 characteristics of living organisms
Movement
Respiration
Sensitivity
Growth
Reproduction
Excretion
Nutrition
What does M mean in MRS GREN
as an action by an organism causing a change of position or place
What does the 2 Rs mean in MRS GREN
Respiration and Reproduction
Respiration
the chemical reactions in cells that break down nutrient molecules and release energy
Reproduction
the processes that make more of the same kind of organism
What does the S mean in Mrs GRen
Sensitivity
the ability to detect and respond to changes in the environment
What does the G mean in MRS GREN
Growth
Permenant Change in size
What does the E mean in MRS GREN
Excretement
The removal from organisms of toxic materials and substances in excess of requirements
What does the N mean in MRS GREN
Nutrition
taking in of materials for energy, growth and development
What is a cell
Smallest unit of life
What are all living organisms made from?
Cells
Structure of animal cells
There’s a nucleus, cytoplasm, cell membrane
Structure of plant cells
Permanent vacuole, chloroplasts, and cell wall
Function of nucleus
contains genetic material, which controls the activities of the cell
Function of cell membrane
controls the movement of substances into and out of the cell
function of cytoplasm
most chemical processes take place here
Functions of a cell wall
supports the cell and prevents it from bursting when the cell is full of water (turgid)
Functions of chloroplats
Contains chlorophyll, which absorbs light energy for photosynthesis
functions of a vacuole
filled with cell sap to help keep the cell turgid
Differences in structures between typical animal and plant cells
plant cells always have a cell wall made of cellulose, plant cells have chloroplasts, and plant cells have a permenant vacuole filled with cell sap
What structures of cells can be seen under a light microscope
nucleus, cytoplasm, cell membrane, chloroplasts, and cell wal
What structures of the cell can’t be seen under a light microscope
Ribosomes and mitochondria
What is the function of ribosomes
produce proteins
What is the function of mitochondira
o generate the energy, powerhouse of the cell
EXamples of speciallised cells
cilliated, sperm, root hair, palisade mesophyl, and red blood cells
What is the function of a cilliated cell, where is it in the body, and what are its adaptaions
lines the trachea, contained cilia hair-like structure which waft mucus and trapped dust particles out of the respiratory system. Also it has lots of mitochondria to support this action
What is the function of a sperm cell, where is it in the body, and what are its adaptaions
are tiny cells produced by males, they’re meant to feartilise, and an adaptation is that it has a tail which allows it swim, and many mitochondria to provide energy for the journey
What is the function of a root hair cell, where is it in the body, and what are the adaptations
Its purpose is to absorb water and nutrients it’s adaptation is their long projections that maximising water absorption from the soil because of the large surface area.
What is the function and adaptation of red blood cells
transport oxygen, it has concave shape which maximises surface area also it has no nucleus to maximise space
How to find magnification of objects
Magnefication=Drawing size (mm) divided by actual size (mm)
What causes a concentration gradient
A difference in concentration of a specific particle.
How does diffusion occur
The random motion of particles which move it down the concentration gradien
Defintion of diffusion
the net movement of particles from a region of their higher concentration to a region of their lower concentration down a concentration gradient, as a result of their random movement.
What factors affect diffusion
surface area, temperature, concentration gradients and diffusion distance.
How does surface areea affect diffusion
the more surface area there’s the faster diffusion as more particles are exposed to surroundings
How does temperature affect diffusion
Higher temperature leads to faster diffusion this is because it increases kinetic energy leading to particles to move faster to areas of low concerntration
How does concentration gradient affect diffusion
Greater concentration gradient leads to faster diffusion, as this means there’s a greater difference in concentrations leading to a stronger driving force for diffusion
How does diffusion distance affect diffusion
Shorter diffusion distance leads to faster diffusion as there’s a Lesser distance for particles to travel.
What is needed in order for substances to pass across surfaces
I
Distances that particles need to travel must be small a thin cell membrance
Surfaces must be moist for gases to dissolve
Transport system should maintain a concentration gradient
Large surface area
How do cells move in and out of cell membranes
diffusion
What is osmosis
the net movement of water molecules from a region of their higher water potential (dilute solution) to a region of their lower water potential (concentrated solution), through a partially permeable membrane.
EXamples of high water potential
soil outside with water
examples of low water potential
amount of water in plant which contains other solutes
What happens when a plant cell is covered in a solution of high concentration
water leaves cell thus Plant cells shrink and become plasmolyzed
Cell wall remains intact
What happens when a plant cell is covered in a solution of low concentration
Plant cells swell and become turgid
Turgor pressure increases
Cell wall expands, but not broken
What is the important of water potential and osmosis foruptake of water for plants
Helps maintain:
Turgor pressure
Cell shape
Plant growth and development
cells What ha
What happens when animal cells are immered in pure water
As they have no cell wall they burst
