Unit 1 Biology Flashcards
What is the independent variable?
The variable which is being changed
What is the dependent variable?
The variable being measured/tested
What is the control variable?
The variable you keep
Where should the independent variable be on a graph?
The x-axis
Where should the dependent variable be on a graph?
The y-axis
What does CORMMS mean? And how would you start each point?
C = Change - Start by saying: “The variable you would change is…”
O = Organism - Start by saying: “The organism used in this will be…”
R = Repeat - Start by saying: “To ensure reliability, repeat the experiment 3 times by…”
M = Measurement 1 - Just state the DV and what equipment you use
M = Measurement 2 - Just state the amount of time for each measurement
S = Same - Start by saying: “To keep the experiment fair, ensure that…”
NOTE: use COSMMR instead as it makes more sense (letters still stand for the same thing)
What does MRS C GREN show?
It tells us the characteristics that an organism must have in order to be classified as living
What does MRS C GREN stand for?
M = Movement - Ability of organism to move positions (through deciding)
R = Respiration - Cells chemical reaction can break down nutrient molecules and release energy
S = Sensitivity (senses) - Ability to respond to changes in the environment
C = Control - Ability to regulate internal conditions (like PH)
G = Growth - Ability to increase in size and mass
R = Reproduction - Ability to reproduce and create offspring
E = Excretion - Ability to remove waste products
N = Nutrition - Intake of materials to grow and develop
What organelles are found in an animal cell?
- Nucleus
- Cell membrane
- Cytoplasm
- Ribosome
- Mitochondria
What organelles are found in a plant cell?
- Nucleus
- Cell membrane
- Cytoplasm
- Ribosome
- Mitochondria
- Cell wall
- Vacuole
- Chloroplasts
What organelles are found in a plant cell BUT NOT in an animal cell?
The organelles are: Cell wall, Vacuole and chloroplasts
What is the function of the Nucleus?
It controls the cells activities and also contain genetic material (DNA)
What is the function of the Cytoplasm?
Jelly-like structure and contains dissolved nutrients so chemical reactions can take place
What is the function of the Cell membrane?
It controls the movement of substances in and out of the cell and is porous (permeable)
What is the function of the Ribosomes?
Where protein synthesis occurs (to produce proteins necessary for cell repair, growth, etc)
What is the function of the Mitochondria?
It is the site of aerobic respiration and produces loads of energy (for growth, movement etc)
What is the function of the Cell wall?
ONLY provides structural support to the cell and is made of cellulose and it is freely permeable (substances can enter easily). The cell wall prevents cell from collapsing from stress
What is the function of the Chloroplasts?
The chloroplasts are packed with chlorophyll which absorb light energy for photosynthesis to produce glucose (acts as energy for plants)
What is the function of the Vacuole?
Contains cell sap to keep the cell swollen (keeps cell firm to support the structure)
What are the levels of organisations? (smallest to largest)
Organelle -> Cell -> Tissue -> Organ -> Organ System -> Organism
What is an organelle, cell, tissue, organ, organ system and organism
The main idea is that a larger structure than a smaller one is a group of the smaller structure working together to preform a specific function. For example: a tissue is a group of cells working together to preform a specific function. The only thing that doesn’t follow the rule is the smallest one which is organelle: it is a specialized structure that preforms a specific function in the cell. ORGANISMS are a simply just a living thing
What does differentiate mean?
It means when a cell changes into a specialized form, developing specific functions in an organism or system
What are stem cells?
Cells that can differentiate into various types of specialized cells and grow tissues (originally not specialized)
What is a specialized cell?
A cell which has specific features to carry out a function example: sperm cell
Why can stem cells become any type of cell?
Because stem cells are NOT specialized
What can stem cells be used for?
They can repair damaged organs or even regrow organs in some cases and can also cure diseases.
What are the types of animal stem cells?
There are 2 types: Embryonic stem cells found in embryos and can differentiate into any animal cell type. The second type are Adult stem cells found in adult bone marrow and are limited in the types of animal cells they can differentiate into.
What are types of plant stem cells?
Theres only one type and they are found in the meristems and are called meristematic stem cells which can differentiate into any type of plant cell.
Difference between animal and plant stem cells?
Animal stem cells can only differentiate into types of animal cells. Whilst plant stem cells can only differentiate into types of plant cells.
Why is the use of stem cells considered as unethical?
There are many reasons and 2 of them are: Because of religious reasons and people are unsure if embryos are considered as living
What is a Eukaryote?
It is a cell which contain their genetic material (DNA) in the nucleus and also have membrane-bound organelles. Examples of eukaryotes include: Animal and plant cells, fungi, protoctists (main groups of eukaryotes)
What is a Prokaryote?
It is a cell which doesn’t have a nucleus so the genetic material (DNA)
is stored in the chromosome. Prokaryotes also don’t have membrane-bound organelles. Examples of prokaryotes: Bacteria
What does unicellular mean?
An organism that consists of a single cell and carry out all processes in that 1 cell. Examples: Bacteria, Yeast, protoctists.
What does multicellular mean?
An organism made up of multiple cells that work together to carry out all processes. Examples: Animal and plants, mushroom
What is Saprotrophic feeding?
When organisms secrete digestive enzymes onto the decaying organic matter in order to break down nutrients, and then they organism absorbs the digested molecules.
Which structures are found in a bacteria cell?
- Cell wall
- Cell membrane
- Flagellum (not all)
- Plasmid
- Chromosome
- Ribosome
- Capsule (slime layer surrounding) (not all)
What is the function of the Cell wall in the structure of a bacteria cell?
The cell wall in a bacteria cell is composed of peptidoglycan and protects the bacteria and also maintains shape of the bacteria cell
What is the function of the flagellum?
It controls the movement of the bacteria
What is the function of the plasmid?
Small rings of DNA which contains genetic material
What is the function of the chromosome?
Allows DNA to replicate accurately and has genes to make proteins
What is the function of the capsule?
It protects the bacteria allowing it to remain undetected by the immune system
What do the shapes of bacteria tell us?
It can tell us the species of bacteria it belongs to and the main shapes and species you need to know are:
1) Spherical shape = Cocci
2) Rod-shape = Bacilli
3) Spiral-shape = Spirilla
Definition of pathogen?
Any organism that can cause a disease in a host
What are some types of pathogens?
Viruses, protoctists, fungi and bacteria can sometimes be considered as pathogens but only viruses are ALWAYS considered to be pathogens whilst protoctists, fungi and bacteria can sometimes NOT BE harmful so they aren’t always a pathogen
Examples of pathogens in viruses:
HIV - (Causes AIDS)
Ebola - (Causes Ebola disease)
Tobacco mosaic virus - (affects plants causing mosaic disease)
Examples of pathogens in bacteria:
Salmonella - (Causes food poisoning)
Mycobacterium tuberculosis - (causes tuberculosis)
Examples of pathogens in fungi:
Tinea Pedis - (Causes Athletes Foot)
Examples of pathogens in protoctists:
Plasmodium - (Causes Malaria)
What are parasites and give an example of one:
Parasites are organisms which cannot survive without a host cell as they use the host to carry out living processes (MRS C GREN) An example of a parasite is a Virus.
Are viruses made out of cells?
No they are not made out of cells
What structures are found in a virus?
- Protein coat
- DNA or RNA
- Envelope (not all viruses have)
What does the protein coat do in a viruses cell?
It protects genetic material and helps the virus attach to the host cell
What does the DNA or RNA do in a viruses cell?
Contains genetic material needed for the virus to replicate and control the host cell
What does the Envelope do in a viruses cell?
Provides virus with protection and also helps virus remain undetected by immune system
A type of virus is HIV. What are the effects of HIV, can it be cured and how does it spread?
HIV destroys white blood cells of the immune system which makes the host more vulnerable to other infections. HIV is cannot be cured but it is treatable and it spreads through the contact with certain body fluids. Example: semen, blood, etc
A type of virus is Influenza (flu). What are the effects of influenza, can it be cured and how does it spread?
Influenza can cause the host to have a fever, runny nose and sore throat. It can be cured by taking medications and it spreads by droplets from coughing or sneezing
A type of virus is Tobacco Mosaic (TMV). What are the effects of TMV, can it be cured and how does it spread?
TMV prevents plant cells from producing chloroplast causing the leaves to to have brown spots. There is no cure but you can treat it by cutting the infected part of the plant to potentially cure it. TMV also gets transmitted through contact
What is diffusion?
It is the net (overall) movement of particles from an area of high concentration to an area of low concentration until equilibrium is reached. (concentration of particles are equal within a place)
Does diffusion require energy?
No diffusion is the passive movement of particles so it does not require energy
Factors which can affect rate of diffusion and how?
1) Increase temperature (particles gain kinetic energy therefore move more and collide more often)
2) Increase concentration gradient (more particles in an area, they collide more so move more)
3) Increase in surface area (more space for particles to move)
4) Decrease in diffusion pathway (shorter, quicker and longer, slower)
What is osmosis?
It is the net movement of WATER MOLECULES across a partially permeable membrane from a region of high water concentration to low water concentration
Explain the movement of water molecules
Water molecules move from an area of high concentration (MORE water, LESS solute) to an area of low concentration (LESS water, MORE solute) so the concentrations on both sides are balanced. NOTE: Main thing you need to know is that WATER PARTICLES WILL ALWAYS MOVE TO MORE SOLUTE
What is a partially permeable membrane?
A barrier that only allows certain substances to pass through (like water particles can pass but solute particles cant)
What is a hypotonic solution?
It is when solute concentration OUTSIDE the cell is LOWER than inside of the cell so the water particles move INTO the cell which causes the cell to SWELL and become TURGID. In animal cells they burst but in plant cells, they have a cell wall preventing it from bursting
What is a hypertonic solution?
It is when the solute concentration OUTSIDE the cell is HIGHER than inside the cell so the water particles move OUT of the cell which causes the cell to become shriveled so they become flaccid. In animal cells they shrink but in plant cells, the cell membrane gets peeled off and the plant cell become plasmolysed (cell membrane peeled)
What is an isotonic solution?
It is when solute concentration is equal inside and outside of cell so theres no overall movement of water particles and the cell keeps its shape (water particles still move but at equal ratio)
Does osmosis require energy?
No osmosis is the passive movement of water particles so it does not require energy
What is active transport?
It is the movement of particles against the concentration gradient as particles move from an area of LOW to HIGH concentration using energy (ATP). Active transport also always takes place across a membrane and requires special proteins on the cell membrane to move particles from low to high concentration
Where does the energy for active transport come from (ATP)?
It comes from cellular respiration which happens in the mitochondria when they break down glucose to release energy which is later stored in molecules called ATP. The ATP is then used to power special proteins which moves particles across the membrane
What is cellular respiration?
It is when cells break down glucose to produce energy (ATP)
Where does active transport usually take place?
1) In the small intestines - The vili actively transports nutrients outside of the vili into the blood stream using energy
2) Roots - Nitrate ions enter the root hair cells of plants through active transport
How does surface affect the rate of diffusion?
A larger surface area to volume ratio allows more particles to diffuse at the same time increasing diffusion rate. higher ratio of SA:V = Fast diffusion but Lower ratio of SA:V = Slow diffusion. As the size of an object increases, its SA:V ratio decreases which makes diffusion slower so particles in smaller objects diffuse quicker
Are Plants Multicellular or Unicellular?
Multicellular
Are Animals Multicellular or Unicellular?
Multicellular
Are Fungi Multicellular or Unicellular?
Both as mushrooms are Multicellular Whilst Yeast is Unicellular
Are Protoctists Multicellular or Unicellular?
Unicellular
Can plants photosynthesise?
Yes because have chloroplasts
Can animals photosynthesise?
No because no chloroplasts
Can fungi photosynthesise?
No because no chloroplasts
Can bacteria photosynthesise?
Yes some have chloroplasts
Can protoctists photosynthesise?
Yes some have chloroplasts
Do plants have a cell wall and if so what is it made out of?
Yes and it is made out of cellulose
Do animals have a cell wall and if so what is it made out of?
No
Do fungi have a cell wall and if so what is it made out of?
Yes and it is made out of chitin
Do bacteria have a cell wall and if so what is it made out of?
Yes and it is made out of peptidoglycan
Do protoctists have a cell wall and if so what is it made out of?
No
How do plants store glucose?
In the form of starch
How do animals store glucose?
In the form of glycogen
How do fungi store glucose?
In the form of glycogen
How do bacteria store glucose?
In the form of glycogen
How do protoctists store glucose?
In the form of glycogen and starch
Example of plants?
Oak
Example of animals?
Cheetah
Examples of Fungi?
Mushroom and Yeast
Examples of Bacteria?
Salmonella
Examples of Protoctists?
Plasmodium and Amoeba
How do you make yoghurt?
Sterilize all equipment. Then heat milk to 85-95°C for 15-30 minutes (pasteurization) to kill harmful bacteria. And then cool milk to 45°C to avoid harming good bacteria. Then Lactobacillus bacteria. Lactic acid is produced, lowering the pH. The milk coagulates (liquid becomes more solid), turning it into yogurt.
