Year 9 Biology End Of Year Assessment (Cell Structure, Cell Division cards 1-23 & Transport in Cells)

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What are the main characteristics of a eukaryotic organism?

A eukaryotic organism is an organism whose cells contain membrane-bound organelles, e.g., a nucleus and mitochondria.

True or False? Prokaryotic organisms contain a nucleus.

False. Prokaryotic organisms do not contain a nucleus.

What is a prokaryotic organism?

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.

True. All prokaryotic organisms are single-celled.

True or False? Prokaryotic organisms are always single-celled.

True. All prokaryotic organisms are always single-celled.

What is a plasmid?

A plasmid is a small circular loop of DNA found in prokaryotic cells.

True or False? Eukaryotic cells are larger than prokaryotic cells.

True. 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.

How many micrometres (µm) are in a millimetre (mm)?

There are 1000 µm in 1 mm.

True or False? There are 1,000,000 nanometres in a millimetre.

True. There are 1,000,000 nanometres in a millimetre.

What is 1,000,000 in standard form?

1,000,000 in standard form is 1 x 10⁶.

True or False? To convert a measurement from nanometres to micrometres you must multiply by 1000.

False. To convert a measurement from nanometres to micrometres you must divide by 1000.

If a eukaryotic cell is 100µm wide and a prokaryotic cell is 1µm wide, how much bigger is the eukaryotic cell in terms of orders of magnitude?

The eukaryotic cell is 2 orders of magnitude wider than the prokaryotic cell.

What separates cells from their surrounding environment?

The cell membrane separates cells from their surrounding environment.

Name the largest organelle present within animal cells.

The largest organelle within animal cells is the nucleus.

Name the structures present in plant cells that are not present in animal cells.

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.

True. Ribosomes are present in plant and animal cells. They are the site of protein synthesis.

Name three organelles found within animal cells.

Organelles present within animal cells are: Nucleus, Mitochondria, Ribosomes.

What is the smallest organelle present in both plant and animal cells?

Ribosomes are the smallest organelle; they are present in both plant and animal cells.

True or False? The gel-like fluid present inside both plant and animal cells is the chloroplast.

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.

False. The role of the nucleus is to store genetic information in the form of DNA. Energy is released by the mitochondria.

What is the function of chloroplasts within plant cells?

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 cells.

False. Plant cell walls provide strength and additional structural support for plant cells. It is the membrane that regulates the passage of substances.

What is the function of the permanent vacuole in plant cells?

The permanent vacuole stores cell sap and provides structural support for plant cells.

True or False? Mitochondria are the site of aerobic respiration.

True. Mitochondria are responsible for releasing energy through the process of aerobic respiration.

Define the term specialised cell.

Specialised cells are cells that have developed specific characteristics that allow them to perform particular functions.

Give an example of a specialised plant cell.

Examples of specialised plant cells include: Root hair cell, Palisade mesophyll cell, Xylem and phloem cells.

Give an example of a specialised animal cell.

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.

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?

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.

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.

False. Sperm cells contain half the amount of DNA contained in normal body cells.

Why are root hair cells adapted to contain a large number of mitochondria?

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?

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 a substance called lignin.

False. Xylem vessels are supported by lignin.

What is cell differentiation?

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.

False. Almost all cells in a multicellular organism contain the same genetic information.

What determines the features of specialised cells?

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.

False. Many types of plant cells retain the ability to differentiate throughout life.

When does most cell differentiation occur in animals?

In animals, most cell differentiation takes place during the early stages of development when the animal is an embryo/fetus (before it is born).

What is a light microscope?

A light microscope is an instrument that uses light and lenses to magnify specimens, allowing visualisation of cells and large subcellular structures.

What does resolution mean in microscopy?

Resolution in microscopy means the ability to distinguish between two closely spaced objects as separate entities.

What is an electron microscope?

An electron microscope is an instrument that uses electron beams instead of light to provide much higher resolution and magnification than light microscopes.

True or False? Electron microscopes use light beams for imaging.

False. Electron microscopes use electron beams for imaging.

True or False? Upon the invention of the light microscope in the 17th century, scientists were able to view cell structure in detail.

False. The first light microscopes allowed only very basic details of cell structure to be observed, such as cell shape and plant cell walls.

What is the formula for calculating magnification?

Magnification = Image size ÷ Actual size.

True or False? Magnification has units.

False. Magnification does not have any units and is just written as, e.g., x10 or 5000x.

What is the equation for calculating the actual size of a specimen?

Actual size = Image size ÷ Magnification.

What is the purpose of a magnification scale in microscope drawings?

A magnification scale is included to show the actual size of the observed specimen.

What is a microscope slide?

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?

Methylene blue is used to stain cheek cells.

True or False? Iodine is used to stain onion cells.

True. Iodine is used to stain onion cells.

What should be avoided when preparing a microscope slide?

Smudging the glass slide and trapping air bubbles under the coverslip should be avoided when preparing a microscope slide.

What is an objective lens?

An objective lens is the lens on a microscope that is closest to the specimen. Most light 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.

False. When viewing a specimen under a light microscope, the low-power lens should always be used first.

What are the key characteristics of biological drawings?

Biological drawings should follow specific rules, e.g., use a sharp pencil, pencil lines should be clear and unbroken, all structures drawn should be in proportion, identifiable features must be labelled using straight, uncrossed lines.

How large should biological drawings be?

Biological drawings should take up at least half of the space available on the page.

Define the term binary fission.

Binary fission is a type of simple cell division by which bacteria multiply.

What happens to the number of bacterial cells after a binary fission event?

The number of bacterial cells increases by a power of 2 (doubles) each time binary fission occurs.

What is aseptic technique?

Aseptic technique is a method used to prevent contamination by unwanted microorganisms when working with cultures.

True or False? Lifting the lid of a petri dish only slightly when transferring bacterial cultures is primarily to prevent air from entering.

False. Lifting the lid of a petri dish only slightly primarily reduces the risk of contamination by other microorganisms.

Why should the inoculating loop be passed through a hot flame before it is used to transfer bacteria to a culture medium?

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?

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 may be harmful.

What is the highest incubation temperature for growing bacteria in a school lab and why?

The maximum allowed temperature for growing bacteria in a school lab is 25°C. This is to restrict the growth of harmful pathogens.

What is an inhibition zone in the context of culturing microorganisms?

An inhibition zone is an area around a disc of antibiotic, antiseptic, or disinfectant where bacterial growth is inhibited.

What is the equation for calculating the area of an inhibition zone?

The equation for calculating the area of an inhibition zone is: Area of inhibition zone = πr², where π = 3.14 and r = the radius of the zone of inhibition.

What is the mean division time of bacteria?

Mean division time is the average length of time that it takes for a bacterial cell in a population to divide.

True or False? A large zone of inhibition indicates that the antibiotic is effective at killing the bacteria.

True. The bigger the zone of inhibition, the more effective the antibiotic is at killing the bacteria.

What is indicated by the absence of a zone of inhibition around an antibiotic disc?

If there is no zone of inhibition, it indicates that the bacteria are resistant to a particular antibiotic.

What should be used as an experimental control when investigating the effect of antibiotics on bacterial growth using agar plates and zones of inhibition?

When investigating the effect of antibiotics on bacterial growth using agar plates and zones of inhibition, the control should be paper discs soaked in sterile water.

How can microorganisms be cultured for use in an investigation?

Bacteria can be cultured in a nutrient broth solution or as colonies on an agar gel plate.

Define the term chromosome.

Chromosomes are structures formed by the coiling of DNA double helices in the nucleus of a cell, visible during cell division, and containing genetic information in the form of genes.

True or False? Each chromosome carries a large number of genes.

True. Each chromosome carries many genes which code for many different types of protein.

How many chromosomes do human body cells contain?

Human body cells contain 23 pairs of chromosomes, totalling 46 chromosomes in diploid cells (often represented as 2n).

Why are chromosomes found in pairs in human body cells?

Chromosomes are found in pairs called homologous pairs. One chromosome in each pair is inherited from each parent. They carry corresponding genes, although they may have different alleles for each gene.

How is the chromosome number in the gametes different to that of body cells?

Gametes (sperm and egg cells) contain the haploid number of chromosomes (n), which is half the diploid number found in body cells.

True or False? Chromosomes are only visible during cell division.

True. Chromosomes condense and become visible during cell division (like mitosis or meiosis) when the DNA coils tightly to form distinct structures.

Define the term mitosis.

Mitosis is nuclear division that results in the production of genetically identical cells. It is used for growth, repair, and asexual reproduction.

True or False? Mitosis results in genetically diverse cells.

False. Mitosis results in genetically identical cells.

What happens to chromosomes before mitosis?

Before mitosis each chromosome replicates, producing two identical copies of each chromosome; one for each of the two daughter cells.

Why is mitosis important in the body?

Mitosis is important in the body to produce new cells for growth, repair of damaged tissues, and the replacement of cells.

What is the outcome of a mitotic division?

A mitotic division produces two genetically identical daughter cells. The daughter cells are genetically identical to each other and to the parent cell.

What cells are not produced by mitosis in animals and plants?

The gametes (i.e. sperm, egg cells, pollen and ovules) are not produced by mitosis, instead they are produced by meiosis.

How many chromosomes are present in a human cell produced by mitosis?

Human cells produced by mitosis contain 23 pairs of, or 46, chromosomes.

True or False? Mitosis is another name for the cell cycle.

False. Mitosis is a part of the cell cycle. The majority of the cell cycle is spent in the stage when the cell grows and DNA replicates.

Name the three stages of the cell cycle.

The cell cycle is made up of cell growth, DNA replication and organelle replication; mitosis (division of the nucleus); cytokinesis (splitting of the cytoplasm).

True or False? Ribosome numbers increase in cells before mitosis occurs.

True. In order for cell division to occur successfully, the subcellular structures must replicate. This includes ribosomes and other organelles such as mitochondria.

Define the term stem cell.

A stem cell is an undifferentiated cell capable of giving rise to many more cells of the same type and from which other cells can arise from differentiation.

True or False? Embryonic stem cells can differentiate to produce most cell types.

True. Embryonic stem cells can differentiate into most, or in some cases all, cell types. This enables them to form the tissues and organs needed during development.

How can stem cells be used to treat diseases such as diabetes?

Stem cells could potentially treat diseases such as diabetes by replacing damaged/unhealthy cells with healthy stem cells, which can continually divide to form more healthy cells.

What is the potential benefit of being able to use a patient's own stem cells in medical treatment?

A potential benefit of being able to use a patient's own stem cells in medical treatment is that stem cells from the same patient would not be rejected by the patient's immune system.

True or False? There is risk of infection when transferring lab-cultured stem cells into a patient.

True. Stem cells cultured in a lab can become infected. Infection can then be passed to patients during therapy.

True or False? There are ethical issues associated with the use of embryonic stem cells in medicine.

True. Many have ethical concerns around the use of embryonic stem cells in medicine. These concerns are related to whether or not embryos should have human rights. Concerns include: Destruction of embryos; Embryos cannot give consent; Embryos are treated as a commodity.

True or False? Adult stem cells have a limited capacity to differentiate.

True. Adult stem cells have a limited ability to differentiate; they can only give rise to a few cell types.

Define the term diffusion.

Diffusion is the spreading out of particles in a solution or a gas, resulting in net movement of particles from a region of higher concentration to a region of lower concentration.

What is a concentration gradient?

A concentration gradient is a difference in concentration between two regions.

True or False? Diffusion is an active process.

False. Diffusion is a passive process that occurs when molecules spread out due to their random movement.

What is a partially permeable cell membrane?

A partially permeable cell membrane allows some substances to pass through while preventing others from entering or leaving a cell.

Name an example of diffusion that takes place in the human lungs.

Examples of diffusion in the lungs include:oxygen diffuses from the inhaled air into the blood through the alveolar lining;carbon dioxide diffuses from the blood into the exhaled air through the alveolar lining.

True or False? The waste product urea diffuses from body cells into the blood.

True. Urea is a metabolic waste product produced in the cells. It diffuses into the blood before being excreted by the kidneys.

What is the relationship between surface area and rate of diffusion into a cell?

As surface area to volume ratio increases, so does the rate of diffusion (and vice versa). This is because a larger surface area provides more space across which diffusion can occur.