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put these in order of size: Organ, Tissue, Organelle, atom, organism, cell, molecule, organ system
atom, molecule, organelle, cell, tissue, organ, organ system, organism
what is an organelle?
small sub-cellular structures
what is a cell?
basic unit of life
what is a tissue?
A group of cells that work together to perform a specific function
what is an organ?
groups of tissues that work together to perform a specific function
what is an organ system?
Organs and tissues that work together to perform a specific function
What is an organism?
Organ systems that work together to enable life
name MRSHGREN
Movement Reproduction Sensitivity Homeostasis Growth Respiration Excretion Nutrition
What is Homeostasis?
Keeping the body system stable and balanced
Name 6 organ systems
Skeletal, Nervous, Circulatory ,Gas exchange ,Digestive, Muscular
Circulatory system function?
to transport nutrients and oxygen round the body
Reproductive system function?
to reproduce the next generation
Excretory system function?
to get rid of metabolic waste mase by the body
Gas exchange function?
To obtain oxygen and get rid of co2
Digestive system function?
To convert large insoluble molecules into small soluble ones
Skeletal/muscular system function?
To support the body and allow movement
nervous system function?
To respond very quickly to change in the surroundings and control vital body processes
immune system function?
To protect the body from microbes and disease
hormonal system function?
To respond to internal changes and control vital body processes. transports chemical signals through blood
is anything smaller than a cell alive?
nope
what are cells made up of?
Organelles (however they cannot survive alone)
What organelles are part of a plant cell?
Nucleus, Mitochondria, cytoplasm, vacuole, cell wall, cell membrane, ribosomes, chloroplasts
Nucleus function?
contains DNA
mitochondria function?
carries out respiration
Cytoplasm function?
chemical reactions take place here
Cell membrane function?
controls what enters/exits the cell
Ribosome function?
where proteins are made
cell wall function?
made of cellulose which gives support/strength to the cell
vacuole function?
storage area which contains cell sap. water pressure in here helps to support the cell
chloroplasts function?
makes food (by photosynthesis) using green chlorophyll
Organelles in an animal cell?
Nucleus, cytoplasm, cell membrane, mitochondria
What is an Eukaryote?
something that has a nucleus
What is a unicellular organism?
organisms that are made of just one cell
Features of a prokaryote?
Have no nucleus (DNA in cytoplasm), Have ribosomes+ cell membrane+ cell wall, Have no mitochondria or vacuole, carries out binary fission
What is Binary Fission?
the process through which asexual reproduction happens in bacteria
feature of an eukaryote?
have a true nucleus, have all the usual structures+ organelles, carries out mitosis
What does a microscope do?
produces a magnified image of an object that are too small to be seen via the naked eye
total magnification equation?
mag of eyepiece x mag of objective lens
what is the eyepiece lens mag?
x10
low/med/high power objective lens mag?
x4, x10, x40
what are the different types of microscopes?
light microscope, scanning electron microscope, transmission electron microscope
features of a light microscope?
max mag = x2000, 2d shape, resolving power = 200nm, object could be alive
features of a scanning electron microscope?
max mag = x500,000, resolving power = 10nm, 3d image, object has to be dead
feature of a transmission electron microscope?
max mag = x1,000,000, resolving power = 0.2 nm, 2d image
microscope magnification definition?
how many times larger an image is compared to real life
resolution definition?
the ability to distinguish between two separate points. the amount of detail that can be seen.
what is the SI (standard) unit for measuring length?
metres
magnification equation for actual size?
I(mage) = A(ctual size) x M(agnification)
specialized cell definition?
cells that have a special adaptation to help them carry out a specific function
what is differentiation?
when cells become specialized they can can change shape and gain/lose specific organelles
differentiation definition?
the production of specialized cells in plants+animals to enable them to carry out specific functions
differentiation in animal cell…
tends to happen at an early stage
differentiation in plants…
happens throughout their life
characteristics of stem cells?
they are unspecialized, they are undifferentiated, replicate themselves for long periods of time to form clones, can differentiate into lots of different types of cells
what are clones?
genetically identical cells
stem cell deffinition?
simple cell which is able to divide and produce many more of the same type. can also produce many differentiated specialized cells.
what are the two types of stem cell found in mammals and humans?
embryonic stem cells and adult stem cells
what are embryonic stem cells?
can differentiate and become any of the specialized cells, tissues and organ of an embryo. can produce a complete organism
what is an adult stem cell?
cells found in adult tissues. they act as a repair system for the body, they replace cells that are lost through normal wear/tear, injury or disease.
how can you get embryonic stem cells?
taken from human embryos
how can you get adult stem cells?
(cannot differentiate into any cell type) mostly used from bone marrow - these can differentiate into any type of blood cell and a few other cell types only.
problem with stem cells in medication?
some say it is unethical and shouldn`t be done.
name for plant stem cells?
meristematic cells (used to produce clones quickly)
uses of stem cells in plants?
medical treatment and disease resistant crops can be cloned (for food)
what are chromosomes?
found in the nucleus-thread like strands of DNA
numbers of chromosomes
you have 46 (23 mum 23 dad)
pairs in males and females
23 pairs in total (46individual) - 22 are the same in males and females however the 23rd is xy in males and xx in females
what is a gene
genes carry the instruction for making proteins within the cell. genes determine the characteristics and features of an organism.
what is DNA ?
Dna is a very long molecule, double helix shape, composed of bases and a sugar phosphate backbone
what are the bases in dna
C-G (remember Car in a Garage)
A-T(Apple in a Tree)
what is the sugar in the sugar phosphate backbone?
deoxyribose
gene definition
as hort section of DNA that codes for proteins.
name some proteins
Enzymes - control chem reactions
antibodies - protect us from diseases
Haemoglobin - carries oxygen round the body
hormones - chemical messages
RUBISCO - essential for photosynthesis
cell cycle?
three stages that a cell in an organism goes through during their life
what are the stages in a cell cycle?
1 - interphase
2- mitosis
3- cytokinesis
cell cycle - what happens
1 - G1 (the cell grows)
2- S (synthesis, cell copies its DNA)
3- G2 (cell gets even bigger)
4 - M (mitosis, cell division (has 4 parts)
what are the stages of mitosis?
Prophase, Metaphase, Anaphase, Telophase
Mitosis definition
a form of nuclear division which produces genetically identical copies of cells. (bacteria cannot because there is no nucleus)
mitosis means that…
each daughter cell has the same number of chromosomes as the parent cell. this is called a diploid number of chromosomes (in humans its 46)
when does mitosis occur?
during growth, repair, and asexual reproduction (in dome organisms)