SB1 - 3 Flashcards
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What are the 2 types of stem cells?
Adult stem cells and embryonic stem cells
What is the interphase process?
When all sub cellular structures are replicated exactly to 94 chromosomes
What is mitosis?
cell division used to produce 2 genetically identical daughter cells
Disadvantages of using stem cells in medicine
Ethical issues, causes cancer, immune system may kill of the medicine
What is the longest part of mitosis?
The interphase
What types of cell do mitosis only take place in?
Diploid (46 chromosomes)
How do you calculate plant growth?
Final mass - starting mass
———————————— x 100
starting mass
What are meristems and where are they located?
Part of a plant where mitosis happens quickly. Found in plants shoots and roots
What can adult stem cells specialise into?
Blood type cells like platelets, red blood cells, whote blood cells, partly specialised immune system cells
What are the purpose of receptor cells?
To detect stimuli
What are the 2 types of nervous systems?
Central nervous system and peripheral
Does a motor neurone contain a dendron?
No but it contains an axon
How can we spot the difference between a sensory and motor neurone
Where the cell bodies are placed
What is the purpose of dendrites
They receive impulses from receptor cells
What is the purpose of the myelin sheath?
Its a fatty later that insulates the neurone allowing electrical impulses to travel faster
What is a synapse and neurotransmitter?
Synapse - A gap between 2 neurons they are used for strength and direction
Neurotrasnmiter - chemical released into a synapse
What is a reflex arc?
Neurone pathways which bypass parts of the brain involved in processing info
Name the 4 parts of the brain and their functions.
Medulla oblongata - controls heart and breathing rate
Cerebral cortex - controls personality, behaviour, language consciousness etc.
cerebellum - posture and balance
brain stem/spinal cord - connects to the spinal cord
What is a cataract?
A cataract in the eye is a protein which builds up inside the lens creating a ‘cloudy’ blur in vision.
How do short and long sighted people’s vision work?
Short sighted people- have longer eyeballs which means the rays are too short to reach the retina .
Long sighted people- have shorter eyeballs which means the image focuses behind the retina.
Why do our pupils either expand or shrink?
Our pupils expand or shrink to protect the eye from damage. Its a reflex action.
List the parts of the eye and their processes.
*use sticky notes
How is food moved through the digestive system?
peristalsis
What is asexual reproduction and what are advantages and disadvantages?
Asexual reproduction - doesn’t require fertilisation, only requires 1 parent.
advantages - much quicker, only 1 parent, ideal for areas that have unequal amounts of gender.
disadvantages - both vulnerable to disease since they are both genetically identical.
What is asexual reproduction most rare and common in.
rare in vertebrates.
common within invertebrates.
What is meiosis?
A type of cell division used to produce haploid gametes.
What is a gene and genome?
gene - a section of DNA which contains instructions to make a protein.
genome - all of an organisms DNA
Explain the process of meiosis.
1st the interphase happens
2nd the chromosomes split into pairs
3rd the pairs then separate again into 2 haploid gametes
What are the 4 bases in DNA?
A - Adenine
T - Thymine
C - Cytosine
G - Guanine
What makes genes slightly different from person to person?
Because we have little differences in our genes caused by slightly different orders of bases in our DNA.
What forms the backbone of a double helix?
Sugars (deoxyribose)
Phosphates
Describe the stage of transcription (1) during protein synthesis.
- Enzyme RNA polymerase binds to a non-coding section of DNA
- Enzyme separates DNA strands
- RNA polymerase adds complimentary RNA nucleotides to template strands
- Nucleotides link forming a mRNA
Describe the stage of translation (2) during protein synthesis.
- mRNA strand travels out nuclear pores
- mRNA strands attach to ribosomes
- Ribosomes move along mRNA strand 3 bases at a time
-each 3 bases is called a codon. - At each codon a molecule of tRNA with complimentary anticodons line up.
- each tRNA molecule carries a specific amino acid - As ribosomes move along it joins amino acids together forming a polypeptide.
What is cystic fibrosis caused by?
A recessive allele
How is your blood group determined?
By the type of marker molecules you have on the outside of your red blood cells.
what is the definition of codominant?
when both alleles for the gene affect the phenoytype
explain sex linked disorder in males and females.
If a males Y chromosomes is missing some genes found on the X chromosome this means the male will only have one allele for some of the genes on the X chromosome. If the allele for one of these X chromosome genes causes a genetic disorder the man will develop this disorder.
since females have the same chromosomes (XX) she will have a healthy allele on her other X chromosome. If the disorder allele is recessive she wont get the disorder.
What is a sex linked disorder
disorders that show a different pattern of inheritance in men and women
What is variation and the 2 types?
Changes in the characteristics of an individual within a population.
1. Genetic variation - where different alleles are inherited during sexual reproduction.
2. Environmental variation - Where your characteristics are affected by your surroundings.
What is discontinuous and continuous variation? And how can it be shown?
Discontinuous - where data can only take a limited set of values. Frequency bar chart with gaps
Continuous - where data can be any value in a range.
Frequency bar chart without gaps.
how is a calorimeter used?
As the food burns, energy is transferred
by heating to the water. The change in
temperature of the water is a measure of
the amount of energy released from the
food.
