Biology (B1) Flashcards
What is the main difference between a prokaryotic and a eukaryotic cell?
Eukaryotic have their DNA contained within a nucleus while for prokaryotes the DNA is free in the cytoplasm
Give 2 examples of a eukaryotic cell
Animal and plant cells
Give an example of a prokaryotic cell
Bacteria cell
Eukaryotic cells have which sub-cellular structures?
Animal and plant cells- cell membrane, cytoplasm, genetic material in a nucleus, mitochondria, ribosomes
Plant cells only- cellulose cell walls, chloroplast
Name the different parts of an animal cell
Cytoplasm
Nucleus
Ribosome
Mitochondria
Cell membrane
What is the function of cytoplasm?
Where chemical reactions take place
What is the function of mitochondria?
Where most of the reactions for aerobic respiration takes place
What is the function of the nucleus?
Contains genetic material (DNA) that controls the activities of the cell
What is the function of the cell membrane?
Allows substances to enter and leave the cell
Name the parts of a plant cell
Cytoplasm
Nucleus
Ribosomes
Vacuole
Mitochondria
Cell membrane
Cell wall
Chloroplast
What is the function of the permanent vacuole?
Filled with cell sap
What is the function of the chloroplasts?
Absorbs light for photosynthesis
What is the function of a cell wall
Strengthens the cell
Whats is the approximate size of a prokaryotic cell?
0.1 - 5.0 micrometers (μm)
What is the approximate size of a eukaryotic cell?
10 - 100 micrometers (μm)
What is bigger? A prokaryotic or a eukaryotic cell
Eukaryotic
Define ‘cell differentiation’
A cell becoming specialised to perform a particular function
Define ‘cell division’
The splitting of a cell into two genetically identical daughter cells
Name 3 specialised cells in animals
Muscle cell
Nerve cell
Sperm cell
Name 3 specialised cells in plants
Root hair cell
Phloem
Xylem
State one adaptation of a muscle cell
Lots of mitochondria for releasing energy for contraction
State the function of a sperm cell
Fertilise the female egg cell
State 3 adaptations of a sperm cell
Flagellum for movement
Lots of mitochondria to release energy for movement
Enzymes in its head (acrosome) to penetrate egg
State the function of a nerve cell
Carry information as electrical impulses from one part of the body to another (transfer electrical impulses)
State 3 adaptations of a never cell
Dendrites to connect to other neurones
Long axon to cover large distance
Myelin sheath to speed up impulse
State the function of a root hair cell
Absorb water and mineral ions from the soil
State 2 adaptations of a root hair cell
Large surface area
Lots of mitochondria for energy for active transport of mineral ions
State the function of a xylem cell
Carry water from roots to leaves
State 3 adaptations of a xylem cell
Lignin to strengthen walls
No end walls (hollow tubes)
Made from thick dead tissue
State the function of a phloem cell
Transport sucrose within a plant
State three adaptations of a phloem cell
Made from living tissue
End walls have sieve cells to allow sucrose through
Lots of mitochondria for energy for active transport
State the magnification equation
Image size= Actual size x Magnification
Which microscope has the highest magnification?
Electron microscope
Which microscope has the lowest resolution?
Light microscope
Which microscope produces 3D images?
Scanning electron microscope
Define ‘cell’
The basic building blocks of all living organisms
Define’tissue’
A group of cells with a similar structure that work together to carry out a particular
and function
Define ‘organ’
A group of different tissues that work together to perform specific functions
Define ‘organ system’
A group of different organs working together to fulfill a function
Define ‘organism’
Organ systems working together to form an organism
What is meant by ‘‘centi’’?
1/100th (1 hundreth of a meter)
What is meant by ‘‘milli’’?
1/1000th (1 thousandth of a meter)
What is meant by ‘‘nano’’?
1 billionth of a meter
How do you convert from millimetres to nanometres?
x 1000
What is diffusion?
The overall movement of particles from a high concentration to a low concentration (down the concentration gradient)
Give 2 examples of diffusion in humans
CO2 and O2 in gas exchange
Urea from cells to blood
Give 4 factors that affect the rate of diffusion
Concentration gradient
Temperature
Surface area of membrane
Distance
How are single celled organisms adapted for diffusion?
Large surface area : volume ratio
How is the lungs adapted for exchanging materials?
Alveoli large surface are:volume ratio
Surface is moist
Good blood supply
How is the small intestine adapted for exchanging material?
Villi for large surface area
Villi one cell thick
Good blood supply
How is the gills adapted for exchanging materials?
Large surface area
Moist
Good blood flow to main concentration gradient
How is the roots adapted for exchanging materials?
Large surface area : volume ratio
Lots of mitochondria for energy for active transport
Give 4 ways to increase the rate of transport
Large surface area
Thin membrane
Efficient blood supply (in animals)
Well ventilated (in animals)
What is osmosis?
The movement of water particles from a high to a low water potential across a partially permeable membrane
What is active transport?
The movement of particles from a low to a high concentration against the concentration gradient
What does active transport require?
Energy from respiration
Put in order of size:
genes, chromosomes, cell, nucleus, DNA
DNA
gene
chromosomes
nucleus
cell
Name 3 stages of the cell cycle
Interphase
Mitosis
Cytokineses
Describe 3 things that happen during Interphase
The cell grows
Chromosomes are replicated
More mitochondria and ribosomes are made (organelles increase)
Describe what happens during mitosis
Chromosomes line up in the middle
Chromosomes pulled to opposite ends of the cell
Describe what happens during cytokineses
Cell membrane and cytoplasm split into two
State why the cell cycle is important
More cells are made for growth and repair
State what is produced in the cell cycle
Two genetically identical daughter cells
Which type of cells does mitosis produce?
Diploid cells
Define ‘stem cell’
An undifferentiated cell
A cell that can differentiate into a specialised cells
Name 2 places where stem cells can be found in humans
Embryos (Embryonic stem cell)
Adult bone marrow
Name where stem cells are found in plants
Meristems
State 2 conditions the stem cells can be used to treat in humans
Paralysis
Type 1 diabetes
State 2 uses of stem cells in plants
Clone rare species
Produce disease resistant crops
Describe what is meant by ‘‘therapeutic’’ cloning
Using clones of a patients own stem cells to treat them
Which cells are required for therapeutic cloning?
Egg cell and normal body cell from patient
State 2 objections to using stem cells in treatment
Potential transfer viral infection
Ethical/religious obligation
What are the risks of stem cell transplant?
Immune rejection
Relies on donors (shortage)
Cause cancer
Viral infection transfer
Immunosupresant drugs
What is a clone?
A genetically identical organism which has been produced asexually
Define ‘asexual’
Reproduction involving only one parent
Which chemical is used to stain animal cells?
Methylyne blue
Which chemical is used to stain plant cells?
Iodine
Define ‘resolution’
How clear the image is and the ability to distinguish between two points which are close together on an object.
What can adult bone marrow stem cells differentiate into?
Red blood cells
White blood cells
Platelets
Embryonic stem cell can differentiate into anything so they are?
Totipotent
How does high temperature affect the rate of diffusion?
Particles diffuse quicker because they have more kinetic energy
How does a large surface area affect the rate of diffusion?
Higher rate of diffusion
Step 1 of “adult cell cloning”
Remove nucleus from unfertilised egg
Step 2 of “adult cell cloning”
Insert nucleus of adult body cell into empty egg
Step 3 of “adult cell cloning”
Give egg cell electric shock (to make it divide into embryo)
Step 4 of “adult cell cloning”
place embryo into a womb
