Cells And Control Flashcards
What is the cell cycle?
A series of steps that the cell has to undergo in order to divide
What does mitosis produce?
2 genetically identical diploid daughter cells, each with identical sets of chromosomes to the parent cell
What is cell division by mitosis important for?
Growth and development
Why is mitosis a vital part of asexual reproduction?
Type of reproduction that only involves one organism, so to produce offspring it simply replicates its own cells
What are the 5 stages of mitosis?
- Prophase
- Metaphase
- Anaphase
- Telophase
- Cytokinesis
What is interphase?
The longest stage of the cell cycle that involves cell growth
What is a chromosome?
A linear DNA molecule tightly coiled around proteins
Outline prophase
-DNA condenses, chromosomes become visible
-nuclear membrane disappears
Outline metaphase
Chromosomes line up along the cell equator
Outline anaphase
-spindle fibres attach to each chromosome
Outline telophase.
-Nucleus of the cell divides
-New membrane forms around each set if chromosomes
What does cytokines involve?
-division of the cell membrane and cytoplasm
-two genetically identical ‘daughter’ cells produced
What is cancer?
-non-communicable
-uncontrolled cell division results in the formation of a primary tumour
What are stem cells?
Unspecialised cells that can differentiate into a range of different cell types
What does differentiation mean?
The process by which stem cells become specialised ( have a specific function)
Why is cell differentiation important?
Enables the formation of specialised tissue with specific functions
What are adult stem cells?
Stem cells that can differentiate into a limited range of cell types
Where are stem cells found in plants?
Meristems
Where is meristem tissue found?
In regions of the plant when cells are continuously dividing
What are the benefits of using stem cells in medicine?
- treat damage or disease
- used in scientific research
- growing organs for transplants
What is the central nervous system?
Brain and spinal cord
What is the function of the spinal cord?
Connects the peripheral nervous system to the brain
Whats is the function of the nervous system?
Allows an organism to rapidly react to environmental and internal changes
What are neurones?
Nerve cells adapted to quickly transmit nerve impulses
What’s the function of a sensory neurone?
Carries impulses from receptors to the CNS
What’s the function of a motor neurone?
Carries impulses from the central nervous system to effectors
What’s the function of a relay neurone?
Carries impulses from sensory neurones to motor neurones within the CNS
How does the CNS coordinates a response to a stimulus?
Stimulus -> sensory receptor detects stimulus-> sensory receptor sends impulses along the sensory neurons to CNS -> CNS coordinates response -> CNS sends information to effector along motor neuron -> effector produces a response to the stimulus
What’s a synapse?
Small gap between neurones which a nerve impulse is transmitted via neurotransmitters
What’s the reflex arc?
Stimulus -> sensory receptor-> sensory neurone -> relay neurone -> motor neurone -> effector -> response
What’s the function of the cornea?
Refracts light entering the eye
What’s the structure and function of the iris?
- pigmented ring of circular & radial muscles
- controls the side of ou ou, to alter how much light enters the eye
What’s the pupil?
Hole in the iris centre that allows light rays to enter the eye
What’s the function of the retina?
Convers light energy into neural signals which are sent to the brain via the optic nerve
What’s the function of the optic nerve?
It transmits nerve impulses to the brain from the retina
Why is the iris reflex important?
Prevents bright light from damaging the retina
