BTEC Applied Science Unit One Biology 128 Questions with Answers
What is the function of the mitochondria? - CORRECT ANSWER cellular
... [Show More] respiration
What is the function of the ribosomes? - CORRECT ANSWER protein synthesis
What is the function of the smooth endoplasmic reticulum? - CORRECT ANSWER Synthesis and transport of lipids and carbohydrates
What is the function of the Golgi apparatus? - CORRECT ANSWER Modified and packaged proteins into vesicles for transport
What is the function of the lysosomes? - CORRECT ANSWER Digests old cell material and waste
What is the function of the centrioles? - CORRECT ANSWER Form into spindle fibres for cell division
What is the function of the chloroplasts? - CORRECT ANSWER photosynthesis
What is the function of the tonoplasts? - CORRECT ANSWER The membrane around the vacuole to keep it together
What is the function of the vacuole? - CORRECT ANSWER Maintain turgid pressure in the plant cell
What is the function of the plasmodestmata? - CORRECT ANSWER To allow materials to pass through the cell wall
What is the function of the amyloplasts? - CORRECT ANSWER Starch synthesis and storage
Name three organelles which are only in plant cells - CORRECT ANSWER Vacuole, chloroplasts, cell wall
Define eukaryotic cells - CORRECT ANSWER Are part of a multicellular organisms
Define prokaryotic cells - CORRECT ANSWER Are unicellular organisms
Name two differences between eukaryotic and prokaryotic cells? - CORRECT ANSWER Eukaryotic has a nucleus but prokaryotic doesn't my eukaryotic has a membrane bound organelles while prokaryotic doesn't
What two dyes are used to show gram positive and gram negative bacteria? - CORRECT ANSWER Crystal violet and safranin
Describe the difference between gram positive and gram negative? - CORRECT ANSWER Gram negative has thin cell walls so the ethanol washes out the crystal violet, so they appear safranin pink. Gram positive appears purple
Describe the key features of a sperm cell? - CORRECT ANSWER Across one to penetrate the egg, tail for swimming, lots of mitochondria for energy
Describe the features of egg cells? - CORRECT ANSWER Hormones to attract the speed, zona pellucuda to protect the egg, corona radiate to supply protein to developing foetus
What is TEM? - CORRECT ANSWER Transmission electron microscope
What is SEM? - CORRECT ANSWER Scanning electron microscope
Compare TEM and SEM - CORRECT ANSWER TEM produces images of thin slices of material whereas SEM looks at the surface topography. Both are very magnified compared to the light microscopes and require dead samples.
Describe how a light microscope works - CORRECT ANSWER Light microscopes use visible light and magnifying lenses to observe small objects
Describe how an electron microscope works - CORRECT ANSWER They use a beam of electrons in a vacuum with a wavelength of less than 1 nm to visualise the specimen
Give one positive and one limitation of light microscopes - CORRECT ANSWER Positive - can observe living structures
Negative - relatively low magnification (x500) and resolution (x200nm)
Give one positive and one negative of electron microscopes - CORRECT ANSWER Positive - high magnification (x500000) and resolution (0.1nm)
Negative - destroys the sample
Magnification equation - CORRECT ANSWER magnification = image size/actual size
Describe the key features of a palisade cell - CORRECT ANSWER Found in leaves, they are rectangular box shaped cells that contain chloroplasts. The chloroplasts can absorb light for photosynthesis. Chloroplasts move around in the cytoplasm to maximise the amount of light absorbed
Describe the key features of a root hair cell - CORRECT ANSWER Found in a plants roots near the growing tip. They have long hair like extensions called root hairs. They increase the surface area of the cell to maximise the movement of water and minerals.
Describe the key features of a red blood cell (erythrocytes) - CORRECT ANSWER Biconcave in shape increases the surface area to volume ratio. They are flexible so that they can squeeze through the narrow capillaries. They have no nucleus, this increases space for haemoglobin to carry oxygen
Describe the key features of white blood cells (neutrophils) - CORRECT ANSWER Multi-over nuclei which help them to squeeze through small gaps when travelling to the site of infection. Cytoplasms holds lysosomes that contain enzymes which breakdown pathogens and then ingest them
Describe the location of the squamous epithelial tissue - CORRECT ANSWER Lines organs
Describes the function of the squamous epithelial tissue - CORRECT ANSWER It is one cell thick and forms thin, smooth, flat layers, ideal for rapid diffusion
Describe the location of the ciliated columnar epithelial tissue - CORRECT ANSWER Lines the trachea
Describe the function of the ciliated columnar epithelial tissue - CORRECT ANSWER It is column shaped cells with hair like structures (cilia) along the surface. They protect the lungs by sweeping away pathogens and secreting mucus to trap the pathogens
Describe the location of the endothelial tisuue - CORRECT ANSWER Lines the heart and blood vessels
Describe the function of the endothelial tissue - CORRECT ANSWER The cell provides a short diffusion pathway for substances such as products of digestion into the blood
How is emphysema caused? - CORRECT ANSWER Smoking can irritate and cause the epithelial tissue of the lungs to become inflamed and scarred. The alveoli walls become thicker and produce more mucus. This damage caused the lungs to lose their elasticity
How is atherosclerosis caused? - CORRECT ANSWER Carbon monoxide and high blood pressure can damage the inner lining of arteries. White blood cells repair the damage and encourage muscle and fatty substances to build up under the endothelial tissue rather than on the surface. This can decrease the size of the lumen and cause the heart to work harder
What is the function of the skeletal muscle - CORRECT ANSWER It is attached to bones and controls contraction and relaxation
What is the function of the cardiac muscle - CORRECT ANSWER It is found in the heart, it contracts to make the heart beat
What is the function of the smooth muscle - CORRECT ANSWER It is found in the walls of hollow organs
Describe when slow twitch muscle fibres are used and why - CORRECT ANSWER Good for marathon runners
More effect it is at using oxygen to generate energy (ATP) for continuous and extended muscle constructions over a long time
Describe the makeup of slow twitch muscle dibres - CORRECT ANSWER Less sarcoplasmic reticulum
More mitochondria
More myoglobin
Dense capillary network
Release ATP slowly by aerobic respiration
What is a fast twitch oxidative muscle fibre? - CORRECT ANSWER These are similar to slow twitch but they are able to hydrolyse the ATP more quickly and contract quicker. They are relatively resistant to fatigue.
What is a fast twitch glycolysis muscle fibre? - CORRECT ANSWER These have less myoglobin, mitochondria and capillaries. They have large concentration of glycogen a valuable for anaerobic respiration. They contract quickly but also fatigue
What is an action potential? - CORRECT ANSWER Electrical impulse that travels down the axon triggering the release of neurotransmitters
What is the resting potential of a neuron? - CORRECT ANSWER A neuron is not is not transmitting an action potential and is at rest
What is the myelin sheath? - CORRECT ANSWER covers the axon of some neurons and helps speed neural impulses
What are Schwann cells? - CORRECT ANSWER A type of cell that forms insulating myelin sheaths around the axons of neurons in the peripheral nervous system
How is an action potential generated? - CORRECT ANSWER As an action potential travels down the axon, there is a change in polarity across the membrane. The Na+ and K+ gated ion channels open and close as the membrane reaches the threshold potential, in response to a signal from another neuron.
What is depolarisation? - CORRECT ANSWER An electrical state whereby the inside of the cell is made less negative relative to the outside than at the resting membrane potential. A neuron membrane is depolarised if a stimulus decreases its voltage from the resting potential of -70mV in the direction of zero voltage.
How does a nerve impulse cross a synapse? - CORRECT ANSWER When the impulse reaches the end of the neuron it crosses the synapse in the form of a chemical neurotransmitters. It diffuses across the synapse and initiates an action potential in the next neuron
Two structural features that are found in only animal cells - CORRECT ANSWER Centriole, cilia
What is the function of nucleolus? - CORRECT ANSWER Makes RNA and ribosomes
What is the function of the nucleus? - CORRECT ANSWER Where DNA is stored and the control centre of the cell
What is the meaning of the specialised cell? - CORRECT ANSWER A cell becomes specialised when it's structure is altered. This enables a cell to have a specific function. This process is called cellular differentiation
How the structure of a neutrophil enables it to exit the capillary in order to reach the bacteria? - CORRECT ANSWER It has a flexible nucleus this makes it fit through the pores and squeeze into smaller spaces
What is the function of lysosomes in a neutrophil? - CORRECT ANSWER They contain enzymes which are used to break down bacteria
What is the structure of the myelin sheath? - CORRECT ANSWER Contains your Schwann cells, the cells are flattened, it has little cytoplasm, high fat content, contains a nucleus
Why the speed of conduction is slower in non-myelinated neurones than in myelinated neurones - CORRECT ANSWER There is a lack of insulation in the non-myelinated neurones, which causes the impulse unable to jump across or that there is a loss of iron or shielding
Smokings different risk factors - CORRECT ANSWER Addictive
Nicotine can damage endothelial cells and carbon dioxide
Certain toxins in tobacco can lower the high density cholesterol
Carbon monoxide can get stuck in red blood cells so less oxygen is moving around the body because of red blood cells being stuck
Name the three types of muscle tissues - CORRECT ANSWER Skeletal, cardiac and smooth
What are the two protein filaments found in muscle cells? - CORRECT ANSWER Thin actin
Thick myosin
What are the conditions like inside and outside of the cell when the neurone is at rest? - CORRECT ANSWER The electrical charges on the outside has a positive charge and the inside has a negative charge
What ions enter the cell at the synapse - CORRECT ANSWER Ca2+
What is magnification? - CORRECT ANSWER the ratio of an object's image size to its real size
What is a prokaryotic cell? - CORRECT ANSWER It's a bacteria cell
What is an organelle? - CORRECT ANSWER It's specialised structures found within a living cell
What is resolution? - CORRECT ANSWER It's the ability to distinguish between objects that are close together
What is an eukaryotic cell? - CORRECT ANSWER It is an animal and plant cell
What is the structure of the plasma membrane? - CORRECT ANSWER Composed of a phospholiprobilary with proteins embedded in the layers
What is the structure of the cytoplasm? - CORRECT ANSWER Is a thick, gelatinous, semi-transparent fluid
What is the structure of the nucleus - CORRECT ANSWER The largest organelle and is surrounded by a nuclear envelope. The envelope has nuclear pores which allow the movement of molecules through it. The nucleus contains chromatin
What is the structure of the nucleolus? - CORRECT ANSWER Dense spherical structure in the middle of the nucleus
What is the structure of the rough endoplasmic reticulum? - CORRECT ANSWER Network of membrane bound flattened sacs called cisternae studded with ribosomes
What is the structure of the smooth endoplasmic reticulum? - CORRECT ANSWER Network of membrane bound flattened sacs called cisternae, with no ribosomes
What is the structure of the Golgi apparatus? - CORRECT ANSWER A stack of membrane bound flattened sacs
What is the function of the vesicles? - CORRECT ANSWER Transport vesicles are used to transport materials inside the cell and secretory vesicles transport proteins that are to be released from the cell, to the cell surface membrane
What is the structure of the vesicles? - CORRECT ANSWER Small spherical membrane bound sacs with fluid inside
What is the structure of lysosomes? - CORRECT ANSWER Small spherical membrane bound sacs containing hydrolyric enzymes
What is the structure of ribosomes? - CORRECT ANSWER Tiny organelles attaches to rough ER or free floating in the cell. They consist of two sub units and they are not surrounded by a membrane
What is the structure of the mitochondria? - CORRECT ANSWER They have two membranes. The inner membrane is highly folded to form Cristae. The central part is called the matrix. They can be seen as long in shape or spherical depending on which angle the cell is cut at
What is the structure of the centrioles? - CORRECT ANSWER They are small tubes of protein fibres
What is the structure of the cell wall? - CORRECT ANSWER Made of cellulose forming a sieve like network
What is the function of the cell wall? - CORRECT ANSWER Protects and supports each cell and the whole plant
What is the structure of the chloroplast? - CORRECT ANSWER Has a double membrane and is filled with a fluid called stroma. The inner membrane is a continuous network of flattened sacs called thylakoids. A stack of thylakoids is called a grandma and this contains chlorophyll pigments
What is the structure of the vacuole? - CORRECT ANSWER membrane-bound sacs found in the cytoplasm that contains cell sap
What is the structure of the tonoplast? - CORRECT ANSWER The partially permeable membrane of the vacuole
What is the structure of the amyloplast? - CORRECT ANSWER A double membrane bound sac containing starch granules
What is the structure of the plasmodesmata? - CORRECT ANSWER Microscope channels which cross the cell walls of plant cells
What is the structure of the pits? - CORRECT ANSWER Pores in the cell wall of the xylem
What is the function of the pits? - CORRECT ANSWER Allows water to enter and leave xylem vessels
What is a membrane bound organelle? - CORRECT ANSWER Organelles surrounded by a phospholipid membrane
What is DNA? - CORRECT ANSWER deoxyribonucleic acid, the hereditary material in cells
What is complimentary base pairing? - CORRECT ANSWER Where nitrogenous bases in DNA pair with each other.
What is RNA? - CORRECT ANSWER ribonucleic acid, a long chain of nucleotides
Order of gram staining - CORRECT ANSWER Add crystal violet, add iodine, wash with alcohol and add safranin
What is turgor? - CORRECT ANSWER Rigidity of plant cells due to pressure of cell contents on the cell wall
What is water potential? - CORRECT ANSWER The tendency of a cell to draw in water from outside by osmosis
What is a gamete? - CORRECT ANSWER One set of chromosomes compared to two sets in the parent cells
What is haemoglobin? - CORRECT ANSWER a globular protein which is an oxygen-carrying pigment found in red blood cells
What is a pathogen? - CORRECT ANSWER A microorganism that causes disease
What are ciliated cells? - CORRECT ANSWER Cells with tiny hair like structures
What is the lumen? - CORRECT ANSWER The space inside a structure
What is an artery? - CORRECT ANSWER A blood vessel that carries blood away from the heart
What is the sarcolemma? - CORRECT ANSWER Cell membrane of a striated muscle cell
What is a myofibril? - CORRECT ANSWER Basic rod shaped unit of muscle cell
What is ATP? - CORRECT ANSWER adenosine triphosphate, an enzyme that transports chemical energy within cells for metabolism
What is hydrolyse? - CORRECT ANSWER A chemical reaction was involving breaking down a compound with water
What is anaerobic respiration? - CORRECT ANSWER respiration without oxygen
What is glycogen? - CORRECT ANSWER Many glucose molecules connected and stored in the liver and muscles
What is dendrons? - CORRECT ANSWER Extension of a nerve cell
What is aerobic respiration? - CORRECT ANSWER Respiration with oxygen
What is mV? - CORRECT ANSWER Millivolts, a small voltage potential across a cell membrane
What are the modes of ranvier? - CORRECT ANSWER The gap in the myelin sheath of a nerve cell, between Schwann cells
What are the symptoms of Parkinson's disease? - CORRECT ANSWER Slow movements, speech problems, tremors when moving and poor balance
What is Parkinson's disease? - CORRECT ANSWER Is a generic disease that affects the nervous system, they are not able to produce the natural chemical dopamine, it's a neurotransmitter that helps smooth and normal movements.
What drug replaces the dopamine in the Parkinson's disease? - CORRECT ANSWER L-dopa
What is the cell theory? - CORRECT ANSWER 1665 - first described cells
1674-1683 - they first living cell was observed
1831 - nucleus observed
1839 - universal cell theory
1852 - evidence for the origin of new cells
1860 - spontaneous generation disproved
What is the function of a palisade mesophyll cell? - CORRECT ANSWER Contains chloroplast to absorb light energy for photosynthesis, they move around in cytoplasm absorb as much light
What is the function of the root hair cell? - CORRECT ANSWER Log hair extensions that increase the surface area of the cell to maximise the movement of water and minerals from the soil to the plant root
What is the function of the sperm cell? - CORRECT ANSWER The middle piece contains a lot of mitochondria to supply the energy needed for the tail (undulipodium) to swim.
The head contains enzymes to break down the protective layer of the egg to fertilise it
What is the function of the egg cell? - CORRECT ANSWER Obtained nucleus which houses the genetic material, the zona pellucida is the outer protective layer of the egg, it's attached to a corona radiata, it supply proteins to the egg cell
How are the lungs protected by ciliated columnar epithelial tissue? - CORRECT ANSWER Secrete mucus to help trap any unwanted particles that are present in the air that you breathe in, protects lungs by stopping bacteria reaching the alveoli
What does the central nervous system consist of? - CORRECT ANSWER brain and spinal cord, it is made up of many non-myelinated nerve cells and longer myelinated scone and dendrons that carry nerve impulse
What are neurones? - CORRECT ANSWER The cells that receive and facilitate nerve impulses or action potentials across their membrane and pass them onto the next neuron
What does the neurone consist of? - CORRECT ANSWER A large cell body called a soma with small projections called dendrites and an axon, the end of the axon is called the axon terminal, it's separated from the dendrite by a small gap called a synapse [Show Less]