biology - cells

Created by

Phoebe Stanway

Cards (97)

What type of cell division results in new body cells being produced?
Mitosis
What does diploid mean?
2 sets of chromosomes
3 reasons mitosis is important
growth, repair, asexual reproduction
How many daughter cells are produced in mitosis?
2 daughter cells
What happens in interphase?
DNA replicates, cell organelles duplicate
name the other stages of mitosis
prophase, metaphase,anaphase, telophase, cytokinesis
What happens in prophase?
The nucleus starts to break down and spindle fibres appear
What happens in metaphase?
Chromosomes line up at the MIDDLE of the cell.
Spindle fibers attach to centromere.
What happens during anaphase?
The chromosomes separate and move along spindle fibers to opposite ends of the cell
What happens in telophase?
Nuclear membrane reforms to form 2 daughter cells
Chromosomes decondense
What happens in cytokinesis?
cytoplasm divides, cell surface membrane separates to form two new cells. In plant cells, cell walls are formed.
in asexual reproduction what name is given to the offspring?
Clones
What is the process where cells become specialised?
Differentiation
What is a stem cell?
an undifferentiated cell that can keep dividing to form more stem cells, or differentiate.
name 2 ways a red blood cell is specialised?
Contains haemoglobin to bind oxygen, No nucleus, large surface area, concave shape
What are the two types of stem cells?
embryonic stem cells and adult stem cells
How are stem cells used in medicine?
Bone marrow transplants can replacef aulty blood cells
List 2 potantial risks of stem cell treatments
Stem cells could divide too rapidly and cause a tumor
Disease transmission
rejection by recipient's immune system
Why might some people disagree with using embryonic stem cells?
Destroys a "potential life"
Where are stem cells found in plants?
Meristems in the tips of the roots and shoots.
Define growth
Increase in size as a result of the number of/ size of cells
Where does growth occur in plants?
Meristems in the tips of the roots and shoots
What happens when cells divide uncontrollably?
A tumor forms. it becomes cancer once it invades surrounding tissues.
How does growth occur in animals?
Cell division and diffrentiation
How does growth occur in plants?
cell division, diffrentiation and elongation
What does it mean if a child is on the 75th percentile for height?
75% of children (the same age) are shorter
What is the funtion of the nervous system?
To allow communication between different parts of the body
Name the organs in hte Central Nervous System (CNS)
Brain and Spinal Cord
What is the spinal cord?
A long column of neurones that connect the brain to the rest of the body
What is the funtion of a sensory neurone?
To carry impulses from receptor cells n the sense organs (e.g. skin) to the CNS
What is the funtion of a mototr neurone?
To carry impulses from the CNS to the effectors
What are relay neurones?
Short neurones found in the spinal cord linking the motor and sensory neurones
What feature allows impulses to be transmitted quickly along a neurone?
Long axon. Sensory neurones have a myelin sheath
What is the function of the myelin sheath?
Insulates the neurone to stop the impulse losing energy
Which substance transmits an impulse from one neurone to another?
Neurotransmitter
Describe a synapse
A gap or space between the axon of one neuron and the dendrite of another - this is where neurotransmitters (chemicals) pass the nerve impulse from one neuron to another neuron
What is the name for a change in the environment that the body reacts to?
Stimulus
Describe the path of the reflex arc using parts of the nervous system. 
STIMULUS > receptor cells > sensory neurone > relay neurone> motor neurone > effector > RESPONSE
What is the advantage of a reflex arc?
Allows a fast and automatic response to what the body percieves as danger.
If reaction time is smaller, the response would be ___________ (faster/ slower)
faster