Cells and Control Flashcards
Interphase
DNA and organelles are copied
Prophase
Chromosomes are condensed and the nuclear envelope breaks down
Metaphase
-Chromosomes are lined up in the middle of the cell/the equator
-They are moved by spindle fibers which are extended from the centrioles
Anaphase
-The spindle fibers shorten and separate the 2 sister chromatids at the centromere
-They are pulled to opposite poles of the cell and are now called daughter chromosomes
Telophase
New nuclear envelopes form around each group of chromosomes to make 2 new daughter nuclei
Cytokinesis
The cytoplasm splits to make 2 genetically identical daughter cells
Mitosis
Copying cell division
What is mitosis used for?
Growth, repair, asexual reproduction
What is cancer?
When tumors spread and destroy surrounding tissues
What causes cancers?
Mutations in a cell’s DNA
What are treatments for cancer?
-Surgery (cut out runout if possible)
-Chemotherapy (use drugs that are toxic to continually dividing cells
-Radiotherapy (radiation$
What is used to measure the growth of young babies?
Length, mass, circumference
Stem cell
An undifferentiated cell
Totipotent stem cell
Can differentiate into every type of specialized cell in the body
Pluripotent stem cells
Able to differentiate into most, but not all types of cell in out body
Adult multi potent stem cells
Can only differentiate into a small number of cells in our body
Stimuli
Changes in our environment
Receptors
Detect stimuli
Effector
Makes a response to a stimuli
CNS
Central Nervous System made up of brain and spinal cord
PNS
Peripheral nervous system
Myelin sheath
A fatty sheath that speed up the rate of impulse conduction
Disadvantages of clones
- No evolutionary potential
- All clones susceptible to the same diseases
Zygote
The single cell that we started life as
Chromosomes
Made of DNA and are divided into groups, each one containing instructions to make one particular proteins
Lateral meristem
A group of undifferentiated stem cells in a bud of a plant
Apical meristem
A group of undifferentiated stem cells in a shoot tip and root tip of a plant
Flower bud function
Perform reproduction by making male and female sex cells/ gametes
Leaf function
Perform photosynthesis, transpiration and make food for the rest of the plant
Stem function
To support and hold up the leaves, connect the roots to the leaves and to store food
Root tip function
To absorb water and minerals that the plant needs to survive and to grow using mitosis
Root hair function
To increase the surface area of the shoot tip to maximise the amount of water and minerals that are absorbed
Xylem function
To transport water and minerals from the roots to the stem and the leaves
Palisade mesophyll function
To perform most of the photosynthesis in the leaf by having most of the chlorophyll
Spongy mesophyll function
Has space for gases to exchange for photosynthesis
Stomata function
To take in carbon dioxide and release oxygen
Guard cell function
To open and close the stomata to control what goes in and out of the leaf
Phloem function
To carry carbohydrates from the leaves to the rest of the plant
Axon (Motor and Sensory neurone)
Carry info away from the cell body
Fatty sheath (Motor and Sensory neurone)
- Made of myelin and speeds up the rate of impulse conduction by insulating axon/dendron
- Is a Schwann cell
Dendron (Sensory neurone)
Carries info up a sensory neurone
How is info carried in a nerve cell?
With tiny electrical signals called nerve signals
Synapses definition
Junctions between neurones that allow electrical impulses to be transferred
Synapses function
- Slow down the passage of information
- Ensure that impulses only travel in one direction
- Act as a junction box
Reflex action advantages
- Automatic
- Extremely fast as brain is not involved and only use 2-3 neurones
Reflex arc (Series of Events)
- Stimulus
- Receptor
- Sensory neurone
- Rotary neurone
- Motor neurone
- Effector
- Response
