Topic 2 - Definitons And Concepts Flashcards
What are adult stem cells?
Stem cells that can differentiate into a limited range of cell types, e.g. bone marrow stem cells.
Adult stem cells are distinct from embryonic stem cells, which can differentiate into any cell type.
What is anaphase?
The third stage of mitosis in which the chromatids are pulled to opposite poles of the cell by spindle fibres.
Anaphase follows metaphase and precedes telophase in the mitotic process.
Define asexual reproduction.
A form of reproduction involving a single parent that creates genetically identical offspring.
Asexual reproduction includes processes such as binary fission, budding, and vegetative propagation.
What is an axon?
A long fibre that conducts nerve impulses away from the cell body.
Axons are crucial for the transmission of electrical signals in the nervous system.
What is cancer?
A non-communicable disease caused by changes in the cell that lead to uncontrolled growth and division.
Cancer can affect any tissue in the body and is characterized by the formation of tumors.
What is a cataract?
A cloudy patch which forms on the lens of the eye and prevents light from entering normally.
Affected individuals have blurred vision, difficulty seeing the intensity of colours, and problems with glare. It is treated using surgery to exchange the clouded lens for a synthetic one.
What is the cell cycle?
A series of events that take place in a cell, involving cell growth, DNA replication, and cell division.
The cell cycle consists of phases including G1, S, G2, and mitosis.
Define cell differentiation.
The process by which an undifferentiated cell becomes specialised for its function.
This process is critical in the development of multicellular organisms.
What is cell elongation?
The process by which cells expand and enlarge, enabling the growth of a plant.
Cell elongation is particularly important in plant growth and development.
What comprises the central nervous system (CNS)?
The brain and spinal cord.
The CNS is responsible for processing and transmitting information throughout the body.
What is the cerebellum?
The region of the brain that controls muscle coordination and non-voluntary movement (e.g. balance, posture).
The cerebellum is essential for fine motor control and maintaining equilibrium.
What is a cerebral hemisphere?
One half of the cerebrum. The left hemisphere controls muscles on the right side of the body and vice versa.
Each hemisphere is responsible for different functions, including language and spatial awareness.
What is the largest region of the brain responsible for movement, memory, intelligence, language, and vision?
Cerebrum
The cerebrum consists of two hemispheres.
What is one ‘arm’ of a replicated chromosome called?
Chromatid
What carries genetic information in the form of genes?
Chromosome
A chromosome is a long, coiled molecule of DNA.
What deficiency makes it difficult to distinguish between colours?
Colour blindness
What type of cells in the retina are sensitive to high light intensity and detect different colours?
Cone cells
What is the transparent outer covering that reflects light entering the eye?
Cornea
What imaging technique uses X-rays to create detailed images of internal organs?
CT scan
What is the process called that involves the division of the cytoplasm at the end of mitosis?
Cytokinesis
What are short, branched extensions of dendrons that provide a large surface area to receive nerve impulses called?
Dendrites
What are branched extensions of a nerve cell body that connect to other neurones?
Dendron
What type of cell contains two copies of each chromosome?
Diploid cell
What is an organ, tissue, or cell that produces a response to a stimulus called?
Effector
What type of stem cells are found in very early embryos and are capable of differentiating into any cell type?
Embryonic stem cells
What sense organ contains receptors sensitive to light intensity and colour?
Eye
What is defined as an increase in mass or size?
Growth
What type of cell contains a single copy of each chromosome?
Haploid cell
What is the longest stage of the cell cycle that involves cell growth and DNA replication?
Interphase
What is the pigmented ring of muscles that controls the size of the pupil called?
Iris
What transparent, biconvex structure refracts light and focuses it onto the retina?
Lens
What is long-sightedness?
A defect of the eye where nearby objects appear out of focus due to the convergence of light rays behind the retina.
Corrected using a convex lens.
What does the medulla oblongata regulate?
Unconscious activities such as breathing and heart rate.
What is meristem tissue?
Plant tissues containing undifferentiated stem cells.
What occurs during metaphase?
The chromosomes align at the cell equator.
What is mitosis?
A form of cell division that produces two genetically identical daughter cells from one parent cell.
What does a motor neurone do?
Carries nerve impulses from the central nervous system to the effectors.
What is the function of the myelin sheath?
An electrically insulating layer that surrounds the axon and increases the speed of nerve impulses.
What are neurones?
Nerve cells adapted to quickly transmit nerve impulses.
What are neurotransmitters?
Chemicals used for communication between neurones and their target cells.
What is a percentile chart used for?
To monitor growth or time by comparing measurements to expected values at a certain age.
What is a PET scan?
An imaging technique used to assess the structure and function of the brain through radioactive chemicals.
What occurs during prophase?
The chromosomes condense and the nuclear membrane breaks down.
What is the pupil?
A hole in the centre of the iris that allows light rays to enter the eye.
What is a reflex?
A rapid and automatic response to a stimulus by the body.
What is a reflex arc?
The pathway of neurones involved in a reflex action: stimulus → sensory neurone → relay neurone → motor neurone → effector → response.
What does a relay neurone do?
Carries nerve impulses from sensory neurones to motor neurones within the central nervous system.
What is the Retina?
A light sensitive layer at the back of the eye composed of rod and cone cells. It converts light energy into neural signals which are sent to the brain.
What are Rod cells?
Cells found in the retina that are sensitive to low light intensity (dim light).
Define Sensory neurone.
A neurone that carries nerve impulses from the receptors to the central nervous system.
What is a Sensory receptor?
A specialised structure that detects a specific type of stimulus.
What is Short-sightedness?
A defect of the eye where distant objects appear out of focus due to the convergence of light rays in front of the retina.
How is Short-sightedness corrected?
Using a concave lens.
What are Stem cells?
Cells that are unspecialised and capable of differentiating into a range of different cell types.
Define Synapse.
A small gap between neurones across which a nerve impulse is transmitted via neurotransmitters.
What occurs during Telophase?
The spindle fibres break down, two new nuclear envelopes form around the daughter cells, and the chromosomes disappear.
Fill in the blank: The _______ is a light sensitive layer at the back of the eye.
[Retina]
True or False: Rod cells are sensitive to bright light.
False
Fill in the blank: A _______ is a specialised structure that detects a specific type of stimulus.
[Sensory receptor]
Fill in the blank: Short-sightedness is corrected using a _______.
[concave lens]
True or False: Stem cells can only differentiate into a single type of cell.
False
What happens to spindle fibres during Telophase?
They break down.
