Cell Division Flashcards
List the stages of the cell cycle (mitosis)
Interphase Prophase Metaphase Anaphase Telophase
What happens during interphase?
DNA replication & increase in organelles
What happens during prophase?
Chromosomes condense, and nuclear membrane breaks down
What happens during metaphase?
Chromosomes line up at the equator
What happens during anaphase?
Spindle fibres attach to the centromeres and pull chromosomes to opposite poles
What happens during telophase?
Cytokinesis occurs and then the nuclear membrane reforms
Why is mitosis important for an organism?
Growth
Repair
Asexual reproduction
What is made at the end of mitosis?
Two diploid, genetically identical, daughter cells
Why do some organisms rely on asexual reproduction?
It makes genetically identical individuals very quickly to colonise and area.
What is cancer
A FUCKING BITCH!!
Real definition:
Uncontrolled mitosis forming a mass of abnormal cells (a tumour)
Define growth.
An increase in cell number and size or mass.
What is a stem cell?
An undifferentiated cell
Which measurements are usually recorded to check the growth of a baby?
Length, mass and head circumference.
A baby is measured and is said to be on the 75th percentile. What does this mean?
75% of babies of that age are lighter and 25% are heavier
Fat bby!
What might cause a baby to veer off a percentile line on a growth chart?
Obesity
Malnutrition
What happens to plant cells during elongation?
The vacuoles fill with water, lengthening the cell before the cell wall hardens.
How is the structure of the ciliated epithelial cell related to its function?
Cilia waft mucus away from the lungs
How is the structure of a sperm cell related to its function?
Tail so it can move
Lots of mitochondria for energy
Acrosome enzymes to penetrate the egg
Name specialise plant cell responsible for photosynthesis
Palisade cell
Name a specialised plant cell responsible for absorbing water.
Root hair cell
Which tissue in plants contain stem cells?
The meristems
What is very special about embryonic stem cells?
They have the potential to differentiate into all different types of cell
Where are adult stem cells found?
Bone marrow
Why are adult stem cells less useful than embryonic ones?
They have the potential to become only a limited variety of specialised cells.
Which specialised plant tissue is responsible for transporting water?
Xylem
Which specialised plant tissue is responsible for transporting sugars?
Phloem
Suggest three risks from Stella gem therapy.
Tumours
Diseases
Rejection
What is the usual effect of damage to the spinal cord?
Paralysis
List the component of the stimulus response pathway.
Stimulus Receptor Sensory neurone CNS Motor neurone Effector Response
Which neurone takes an impulse form the CNS to the effector?
Motor neurone
Which neurone takes an impulse from the receptor to the CNS?
Sensory neurone
Which neurone carries messages within the CNS
Relay neurone
What is an effector
A muscle or a gland
What is meant by reaction time
The time it takes to respond to a stimulus
What does a receptor do?
Response to a stimulus
Name a receptor in the skin
Pain
Temperature
Pressure
Receptor
Where to axons carry impulses
Away from the cell body
Dendrites and dendrons carry impulses where?
Toward the cell body
What is the myelin sheath for on some axons?
Insulation
To speed up neurotransmission
Why are neurones long?
To speed up transmission of impulses and to connect with many other cells
What is the gap between two neurones called
A synapse
What diffuses across a synapse?
Neurotransmitters
Do synapses slow down or speed up impulses
Slow them down
Define a reflex
A fast, automatic protective response
Which part of the CNS is often missed out in a reflex in order to speed up the response time
The brain
Why is the use of embryonic stem cells controversial
The cell may have had the potential for human life
Suggest an ethical reason for the use of embryonic stem cells in medicine.
To cure diseases and prevent suffering.
