B1.1: Cell Structure Flashcards
What are the main characteristics of eukaryotic organisms?
(B1.1.1.1)
A eukaryotic organism is an organism whose cell contains membrane-bound organelles.
e.g - a nucleus and mitochondria
True or False.
Prokaryotic organisms contain a nucleus
(B1.1.1.2)
False. Prokaryotic organisms do not contain a nucleus
What is a prokaryotic organism?
(B1.1.1.3)
A prokaryotic organism is an organism whose cells lack a nucleus and other membrane-bound organelles.
True or False.
All prokaryotic organisms are single celled
(B1.1.1.4)
True. Prokaryotic organisms are always single-celled.
Define the term plasmid
(B1.1.1.5)
A plasmid is a small circular loop of DNA found in prokaryotic cells.
True or False.
Eukaryotic cells are larger than prokaryotic cells
(B1.1.1.6)
True.
Eukaryotic cells are larger than prokaryotic cells.
Eukaryotic cells are typically between 10 and 100 µm. Prokaryotic cells are much smaller in comparison to eukaryotic cells, with many measuring ~ 1 µm in size.
What separates cells from their surrounding environment
(B1.1.2.1)
The cell membrane separates cells from their surrounding environment.
Name the largest organelle present within animal cells
(B1.1.2.2)
Nucleus
Name the structures present in plant cells that are not present in animal cells
(B1.1.2.3)
Plant cells have the following structures that are not present in animal cells:
• Cell wall
• Chloroplasts
• Permanent vacuole
True or False.
Ribosomes are present in both plant and animal cells
(B1.1.2.4)
True.
Ribosomes are present in plant and animal cells. They are the site of protein synthesis.
Name 3 organelles found within animal cells
(B1.1.2.5)
Organelles present within animal cells are:
• Nucleus
• Mitochondria
• Ribosomes
*Note that structures such as the cell membrane and cytoplasm are not organelles, so are not acceptable answers here.
What is the smallest organelle present in both plant and animal cells?
(B1.1.2.6)
Ribosomes are the smallest organelle; they are present in both plant and animal cells.
True or False.
The gel like fluid present in both plant and animal cells is the chloroplast
(B1.1.2.7)
False.
The gel-like fluid present in plant and animal cells is the cytoplasm. Chloroplasts are organelles found in plant cells
True or False.
The role of the nucleus is to release energy for the cell
(B1.1.2.8)
False.
The role of the nucleus is to store genetic information in the form of DNA. Mitochondria is released by the mitochondria
What is the function of chloroplasts within plant cells?
(B1.1.2.9)
Chloroplasts absorb light energy during the process of photosynthesis
True or False.
Plant Cell Walls are responsible for controlling the passage of substances in and out of the cells
(B1.1.2.10)
False.
Plant Cell Walls provide strength and additional structural support for plant cells. It is the membrane which regulates the passage of substances
What is the function of the permanent vacuole in plant cells?
(B1.1.2.11)
The permanent vacuole stores cell sap and provides structural support for plant cells
True or False.
Mitochondria are the site of aerobic respiration
(B1.1.2.12)
True.
Mitochondria are responsible for releasing energy through the process of aerobic respiration
Define the term ‘specialised cell’
(B1.1.3.1)
Specialised cells are cells that have developed specific characteristics that allow them to perform particular functions
Give an example of a specialised plant cell
(B1.1.3.2)
Examples of specialised plant cells include:
• Root hair cell
• Palisade mesophyll cell
• Xylem and phloem cells
Give an example of a specialised animal cell
(B1.1.3.3)
Examples of specialised animal cells include:
• Red blood cells
• Nerve cells
• Ciliated epithelial cells
• Sperm/Egg cells
• Muscle cells
True or False.
Root Hair cells have an increased surface area
(B1.1.3.4)
True.
Root hair cells have an increased surface area to allow increased absorption of water and mineral ions from the soil
What is the function of a nerve cell?
(B1.1.3.5)
The function of a nerve cell is to conduct electrical impulses and send signals around the body
True or False.
An adaptation of a muscle cell is that they contain a lot of mitochondria
(B1.1.3.6)
True.
Muscle cells contain a lot of mitochondria to carry out aerobic respiration and provide energy for muscle contraction
True or False.
Sperm Cells contain a full set of chromosomes (46) from the father?
(B1.1.3.7)
False.
Sperm Cells contain half the amount of DNA contained to normal body cells
Why are root hair cells adapted to contain a large number of mitochondria?
(B1.1.3.8)
Root Hair Cells contain a lot of mitochondria to provide energy for the active transport of mineral ions from the soil into the cell
What is the function of a phloem cell?
(B1.1.3.9)
Phloem Cells form a long vessel to allow the plant to transport dissolved sugars and amino acids
True or False.
Phloem vessels are strengthened and supported by substance called lignin strengthening the tubes in providing support for the plant
(B1.1.3.10)
False.
Xylem Vessels are supported by lignin
What is cell differentiation?
(B1.1.4.1)
Cell Differentiation is the process by which a cell changes to become specialised
True or False.
Almost all cells in a multicellular organism contain different genetic information
(B1.1.4.2)
False.
Almost all cells in multicellular organism contain the same genetic information
What determines the features of specialised cells?
(B1.1.4.3)
The features of specialised cells are determined by the expression of genes in the nucleus
True or False.
All plant cells differentiate early in development
(B1.1.4.4)
False.
Many types of plant cells retain the ability to differentiate throughout life
When does most cell differentiation occur in animals?
(B1.1.4.5)
In animals, most cell differentiation takes place during the early stages of development when the animal is an embryo
What does resolution mean in microscopy?
(B1.1.5.1)
Resolution microscopy means the ability to distinguish between two closely spaced objects as separate entities
True or False.
Electron microscopes use light beams for imaging
(B1.1.5.2)
False.
Electron microscopes use electron beams for imaging
What is the formula for calculating magnification?
(B1.1.5.3)
Magnification = image size / actual size
What is the purpose of a magnification scale in microscope drawings?
(B1.1.5.4)
A magnification scale is included to show the actual size of the observed specimen
What is a microscope slide?
(B1.1.5.5)
A microscope slide is a thin, flat piece of glass on which specimens are prepared for observation under a microscope
What stain is used for cheek cells?
(B1.1.5.6)
Methylene Blue
True or False.
Iodine is used to stain onion cells
(B1.1.5.7)
True
What should be avoided when preparing a microscope slide?
(B1.1.5.8)
Smudging the glass slide and trapping air bubbles under the coverslip
What is an objective lens?
(B1.1.5.9)
An objective lens is the lens on a microscope that is closest to the specimen. Most microscopes have several objective lenses at different powers for viewing specimens at different levels of magnification
True or False.
The highest powered objective lens should always be used first when viewing a specimen under a light microscope
(B1.1.5.10)
False.
Low power lens should always be used first
What are the key characteristics of biological drawings?
(B1.1.5.11)
They should follow specific rules:
- Use a sharp pencil
- Pencil lines should be clear and unbroken
- All structures should be drawn in proportion
- Identifiable features must be labelled
Define the term binary fission
(B1.1.6.1)
Binary fission is a type of simple cell division by which bacteria multiply
What is aseptic technique?
(B1.1.6.2)
Aseptic technique is a method used to prevent contamination by unwanted microorganisms when working with cultures.
Why should the inoculating loop be passed through a hot flame before it’s used to transfer bacteria to a culture medium?
(B1.1.6.3)
The inoculating loop should be passed through a hot flame to kill any microorganisms present on the loop.
This prevents contamination.
Why should the lid of the petri dish be secured with tape at intervals around the dish, rather than all the way around?
(B1.1.6.4)
The lid should be secured with tape at intervals, rather than all the way around, to ensure that oxygen can enter the dish; this prevents the growth of anaerobic bacteria which can be harmful
What is the highest incubation temperature for growing bacteria in a school lab? Why?
(B1.1.6.5)
Maximum Temmperature: 25*C
This is to restrict the growth of harmful pathogens
What is an inhibition zone in the context of culturing microorganisms?
(B1.1.6.6)
An inhibition zone is an area around a disc of antibiotic or antiseptic where bacterial growth does not occur
What is the main division time of bacteria?
(B1.1.6.7)
Mean division time is the average length of time that it takes for a bacterial cell in a population to divide
What is indicated by the absence of a zone of inhibition around an antibiotic disc
(B1.1.6.8)
If there is no zone of inhibition, it indicates that the bacteria is resistant to a particular antibiotic
When investigating the effect of antibiotics on bacterial growth, what should be used as an experimental control?
(B1.1.6.9)
The control should be paper discs soaked in sterile water
How can microorganisms be cultured for use in an investigation?
(B1.1.6.10)
Bacteria can be cultured in a nutrient broth solution or as colonies on an agar gel plate
