Biology unit 1 Flashcards
What is a eukaryotic cell?
Multicellular organism that contains a nucleus
What is a prokaryotic cell?
Single-celled organism containing single stranded dna
What is the formula for magnification?
Image size/actual size
What is gram staining?
Technique used to differentiate two large groups of bacteria as being gram positive or gram negative.
Positives of electron microscope?
- Ability to produce powerful magnification
- Offers a high resolution
Negatives of electron microscope?
- Very costly
- It is very large
- Requires high maintenance
- Difficult to identify artifacts
Positives of light microscope?
- Ability to observe living things
- Can observe a wide range of biological activity
- Easy and cheap to use
- Colour
Negatives of light microscope?
- Difficult to identify artifacts
- Low magnification and resolution
Function of the golgi apparatus?
Modifies and packages proteins.
Function of the plasmodesmata?
Enables transport and communication between plant cells.
What organelles are found in plant cells but not animal cells?
- Vacuole
- Cell wall
- Chloroplast
How does the ultrastructure of a bacterium capsule prevent dehydration?
The capsule is selectively permeable which stops water from leaving.
Name the ribosome found in bacteria?
70-s
What is the job of ribosomes?
To make proteins
What is a gamete?
Sex cell
What damage can smoking cause?
- Loses elasticity
- Causes scarring and inflammation
What are cilia?
They are small hair-like protuberances on the outside of eukaryotic cells.
What is the function of the midpiece of a human sperm cell?
Many mitochondria to supply energy for movement
What is the function of root hairs in plant cell
- Increase surface area
- Movement of water and minerals
What is the function of the chloroplast in plant cells?
Photosynthesis
How are red blood cells adapted to their function?
Biconcave disk to increase surface area
No nucleus to increase space for more haemoglobin.
What is the function of a neutrophil cell?
Immune response
how do neutrophil cells help defend the body?
Producing antobodies
What do nuclear pores allow?
Transport of molecules across the nuclear envelope
What is the function of squamous epithelial tissue and where is it located?
Alveoli-short diffusion pathway for the movement of gases
How can arteriosclerosis develop?
Build up of fatty deposits in the arteries
What is the function of endothelial tissue?
Lines the tissue in the heart and blood vessels to protect them
How do ciliated columnar epithelial tissue protect the lungs?
- cilia on the surface of the trachea
- Goblet cells secrete the mucus
- Mucus traps the pathogens
Name the units for size
Milimetre(mm) x 1000 Micrometer(um) x1000 Nanometer(nm)
Squamous epithelial tissue line what
Alveoli
Coloumnar epithelial tissue lines the…
Trachea
Squamous epithelial cells are …
- One cell thick
- present in the alveoli
- used for rapid diffusion
Columnar epithelial cells are …
Have cilia on the surface
Present in the trachea
Have goblet cells
Animal cell components and their function
Mitochondria- to perform cellular respiration.
Ribosomes- makes proteins
Plasma membrane- to protect the cell from its surroundings.
Lysosome - They digest excess or worn out organelles, food particles, and engulfed viruses or bacteria.
Vesicle - They can be used to move molecules, secrete substances, digest materials, or regulate the pressure in the cell.
Smooth endoplasmic reticulum- the synthesis of lipids,
Rough endoplasmic reticulum- to produce proteins.
Vacuole- Contains cell sap
Cytoplasm- It helps to fill out the cell and keeps organelles in their place
Golgi apparatus- packages proteins
Nucleus- Contains DNA and genetic information
Nucleolus- makes ribosomes
What is the counterstain for gram staining
Safranin
What does iodine do in gram staining?
crystallizes the bacteria
What does palisade mesophyll cell have lots of?
Chloroplast
What is actin?
The thin filament
What is myosin?
The thick filament
What are the three types of muscle tissue?
- Cardiac: muscle tissue in the heart
- Smooth: Controlled by the autonomic nervous system
- Skeletal: under conscious control. Often attaches to bones and allows movement.
Describe the process of atherosclerosis?
Endothelial tissue are damaged
- WBC go to site of damage
- WBC form plaque
- Muscle cells form over the plaque
- Over time this breaks and causes blockages.
What is the A band?
Thick and thin
What is the H zone?
Thick only
What is the I band?
Thin only
What does tropomyosin do?
Stops myosin from binding to the actin
Describe the structure of actin?
- Thin filaments
- Long protein molecules that form chains twisted around each other
- Has myosin binding sites
Describe the structure of myosin?
- Thick filament
- Fibrous protein with globular head at one end
- Head region has an ATPase activity and an actin binding site
Describe the structure of titin?
- Large abundant protein of striated muscle
- Stabilises the myosin filaments
- Prevents overstretch and allows muscle to recoil
What do the ion channels do?
- Two ions in nerve impulse are na+ and k+
- Phospholipid bilayer of the axon prevents na+ and k+ ions diffusing across it
- Voltage gated ion channel can be opened/closed tp allow facilitated diffusions of Na+ and K+
- Channels are normally closed
What does the Na+/K+ pump do?
- Actively transports Na+ and K+
- Uses atp to pump 3Na+ and 2K+ in and out of the cell
Name the 7 stages of action potential?
- Resting potential
- Stimulus
- Depolarisation
- Action potential
- Repolarisation
- Hyperpolarisation
- Refractory period
What is the function of the tonoplast?
selectively permeable to allow small molecules to pass through
What is the function of the vacuole?
Ensure a rigid framework in the cell
What is the function of the amyloplast?
Responsible for the synthesis and storage of starch
What is the function of the pits?
Allows water to enter and leave the xylem vessels
What is the function of the grana?
site of light dependant reactions of photosynthesis
What is the function of a neutrophil cell?
immune response
What is gram staining?
technique used to differentiate two large groups of bacteria
What type of ribosome is found in bacteria?
70-s
Where can atheroma be formed?
Endothelial tissue
During muscle contraction, the A band….
Stays the same length
During muscle contraction, the H zone…
Gets shorter
What happens during the refractory period?
Sodium channels are inactive
What is the function of the mitochondria?
to perform cellular respiration.
What are the two functions of plasmids in bacteria?
- contains genes
- Allow genes to be transferred
What are the contractile proteins found in a myofibril?
Myosin and actin
What is the cell surface membrane of a skeletal muscle cell?
Sarcolemma
What are 6 specialised cells?
- Palisade mesophyll
- Egg
- Red blood cell
- White blood cell
- Root hair
- Sperm
What is the tip of the sperm cell called?
Acrosome
What is in the middle part of the sperm cell?
Mitochondria
What is the tail of the sperm cell called?
Undulipodium
What is the outer protective layer of the egg cell called?
Zona pellucida
What is a myofibril?
They make up muscle cells and are composed of two filaments; actin and myosin.
What are the components of fast twitch muscle fibres?
- Used for fast movements
- Fast contraction speed
- Anaerobic respiration
- Low number of mitochondria
- Lower number of blood vessels
What are the components of slow twitch muscle fibres?
- Used for endurance movements
- slow contraction speed
- Aerobic respiration
- High number of mitochondria
- Higher number of blood vessels
What is noradrenaline?
Found in neurons that regulate heart rate,breathing rate and brain activity.