biology Flashcards
animal and plant eukarytic cells contiain
cell membrane
cytoplasm
nucleus
mitochondrion
cell wall (plant only)
chloroplast (plant only)
vacuole (plant only)
prokaryotic cells contain
cell membrane
cytoplasm
cell wall
chromosomal DNA/no ‘true’ nucleus
plasmid DNA
levels of organisation
cells to tissues to organs to organ systems
interphase
cell grows and DNA is copied
mitosis
division leading to two daughter cells that have the
same number of chromosomes so are genetically identical to each other and the
parental cell
role of mitosis in growth
increasing cell numbers
repair of tissues
replacement of worn out cells
asexual reproductiin
what is cancer the result of
changes in cells that lead to uncontrolled growth and division
meiosis
division that produces daughter cells, known as gametes,
in which the chromosome number is halved from diploid to haploid so they have
a single set of chromosomes
each daughter cell produced by meiosis will be
genetically different
role of meiosis
reducing the chromosome number
in meiosis, when does the cell have the full chromosome complement again
at fertilisation
asexual reproduction offspring are
genetically identical when no mutations occur
sexual reproduction offspring are
genetically different to eachther and the parents leading to increased variation
most mammals, inluding humans, females are ____ and males are _____
XX
XY
nucleus is the site of
genetic material/chromosomes/genes in plant and animal
cells
what is the genome
the entire genetic material (DNA) of an organism
chromosomes contain
DNA
what is DNAA
a polymer mad eup of two strands forming a double helix
DNA is made from
four different nucleotides, each consisting of a
common sugar and phosphate group along with one of four different bases
attached to the sugar.
adenine pairs with
thymine
guanine pairs with
cytosine
the sequence of dna bases is
the gentic code
genetic code is read as
triplets
each triplet codes for
an amino acid
what does protein sysntheiss involve
production of proteins from amino acids
what is a gene mutation
a change in DNA
most mutations have
no effect on the phenotype, some will have a
small effect, whilst occasionally others will determine the phenotype.
what is genetic enginerring
i. taking a copy of a gene from (DNA/chromosomes of) one organism.
ii. insertion of that gene into the DNA of another organism.
iii. the roles of restriction enzymes and ligases.
embryonic stem cells can give rise to
any cell type
can stem cells always give rise to any cell type
no only embryonic. animals lose this ability as they mature
is there usually genetic variation within a population of species
yes, extensively
describe evolution
a change in the inherited characteristics of a population
over time through a process of natural selection which may result in the
formation of a new species.
how can evolution occur through natural selection of variants
that give
rise to phenotypes best suited to their environment.
understand antibiotic resistance and that it is an example of
evolution through natural selection
can variation be inherited
yes resulting in a range of phenotypes
enzymes are
biological catalysts
mechanism of enzyme
active site
enzyme specificity
lock and key
induced fit
factors affecting rate of enzyme action
temperature
pH
role of amylase in digestin
catalyses the breakdown of starch into maltose in the mouth and small intestine
role of protease in digestion
catalyse the breakdown of proteins into amino acids in the stomach and small intestine
role of lipase in digestion
catalyse the breakdown of fats and oils into fatty acids and glycerol in the small intestine
cellular respiration equation
C6H12O6 + 6O2 –> 6CO2 + 6H2O + 38ATP
aerobic respiration equation
C6H12O6 + 6O2 –> 6CO2 + 6H2O + 38ATP
aerobic respiration process
the process by which organisms use oxygen to turn fuel, such as fats and sugars, into chemical energy
glycolysis
link reaction
krebs
oxidative phosphorylation
https://www.thesciencehive.co.uk/respiration-a-level#:~:text=1%20Aerobic%20Respiration.%20Aerobic%20respiration%20is%20made%20of,oxygen%20-%20this%20is%20called%20anaerobic%20respiration.%20
the CNS is
the brain and spinal cord
white blood cells are invovled in
antibody production adn phagocytosis
platelets are involved in
blood clotting
plasma is involved in
transport of blood components and other substances like hormones, antibodies, urea and carbon dioxide and distribution of heat
relay neurons function
Passes signals between neurons
motor neuron function
transmit signals to muscle cells or glands to control their functional output from the brain
what diseases are formed by many factors
cardiovascular disease, many forms of cancer, some lung and liver
diseases and diseases influenced by nutrition, including type 2 diabetes
how can cardiovascular disease be managed
using life-long
medication (including statins, anti-coagulants and anti-hypertensive drugs),
surgical procedures (including stents and bypass for coronary heart
disease), and lifestyle changes (including reducing smoking, more exercise
and a balanced diet).
function fo sensory neurons
Sensory neurons get information about what’s going on inside and outside of the body and bring that information into the CNS so it can be processed.
reflex arc
stimulus
receptor
sensory neurone
relay neurone
motor neurone
effector
response
importance of interdependence in ecosystems
predation
mutualism
parasitism
competition
photosynthetic organisms are
the primary producers of food in ane cosystem and therefore biomass
function of the respitory system
The respiratory system consists of organs and structures that allow us to breathe by taking in oxygen and expelling carbon dioxide.
process of ventilation
The human respiratory system is adapted to allow air to pass in and out of the body, and for efficient gas exchange to happen. Exercise and smoking both affect the lungs and circulatory system. The ribs, intercostal muscles and diaphragm all play important roles in ventilation (breathing).
process of gas exchange
Gas exchange is the biological process through which gases are transferred across cell membranes to either enter or leave the blood.
why is a high surface area to volume ration important for gas exchange
The surface area to volume ratio of a cell must be such that the cell membrane has enough surface area to adequately serve the internal contents (volume) of the cell, including the adequate exchange of gases.
antibody production
When a specific B lymphocyte is activated following antigen presentation, it divides into plasma cells and memory cells
Plasma cells are short-lived and secrete high numbers of antibodies that are specific to a particular antigen
Plasma cells will secrete ~ 2,000 antibody molecules per second into the bloodstream for roughly 4 to 5 days
formation of memory cells
When a B lymphocyte is activated and divides to form plasma cells, a small proportion will differentiate into memory cells
Memory cells are long living and will survive in the body for many years, producing low levels of circulating antibodies
heart rate is
pulse. no of times your heart beats a minute
ECG
It is used to record the electrical activity of the heart from different angles to both identify and locate pathology. Electrodes are placed on different parts of a patient’s limbs and chest to record the electrical activity.
levels of organisation in an ecosystem
indiviual
population
community
ecosystem
biome
biosphere
what causes a popualtion to change size
lightt
nutrition
habitat
competition
predation
resources
disease
importance of the water cycle
maintaining aquatic ecosystems
availability of water to all living organisms
evaporation
condensation
precipitation
collection
composition of blood
plasma
white blood cells
platelets
red blood cells
function of blood
breathing
excretion
hormones
temperature
acid-base balance
homeostasis
structure of the digestive system
mouth
oesophagus
liver
gall bladder
pancreas
small intestine
appendix
salivary glands
stomach
large intestine
rectum
anus
fucntion of the digestive system
Motility, digestion, absorption and secretion
peristalsis
the involuntary constriction and relaxation of the muscles of the intestine or another canal, creating wave-like movements that push the contents of the canal forward.
egestion
the process by which the remains of food that haven’t been used by the body are eliminated. It corresponds to the final phase of the food digestion process and is not the same as excretion.
function of the excrety system
remove waste from the body
function of the nephron
regulating the concentration of sodium salts and water by filtering the kidney’s blood, excreting any excess in the urine and reabsorbing the necessary amounts.
role of kidneys in homeostasis
regulating glucose homeostasis through utilization of glucose, gluconeogenesis, and glucose reabsorption via sodium glucose co-transporters (SGLTs) and glucose transporters.
regualtion of blood glucose leves occurs how
negative feedback
role of insulin
controlling blood sugar and energy absorption. Insulin is a chemical messenger that allows cells to absorb glucose, a sugar, from the blood. The pancreas is an organ behind the stomach that is the main source of insulin in the body.
role of glucagon
control glucose (sugar) levels in your blood. Glucagon prevents your blood sugar from dropping too low. stimulates liver to break down glycogen into glucose
how can type 1 diabetes be treated
- Taking insulin 2. Carbohydrate, fat and protein counting 3. Frequent blood sugar monitoring 4. Eating healthy foods 5. Exercising regularly and maintaining a healthy weight
how can type 2 diabetes be treated
- Healthy eating 2. Regular exercise 3. Weight loss 4. Possibly, diabetes medication or insulin therapy 5. Blood sugar monitoring
regulation of water content occurs how
adh
ADH does what
increases permability of the nephron by introducing mroe p
how does the body regulate temperature
through the hypothalamus by sweating or shivering or vasodilation/constriction
role of adrenaline
prepares body for fight or flight
liver converts glycogen to glucose
vasodilation of aterioles in brain and muscle
dilation of air pathways for higher rate of gas exchange
increase in heart rate
vasconstriction of aterioles in the gut and other organs
thyroxine in negative feedbck
The hypothalamus and pituitary gland have important roles in detecting and controlling thyroxine levels.
Low thyroxine levels in the bloodstream stimulate the hypothalamus to release TRH and this causes the pituitary to release TSH so the thyroid releases more thyroxine. So blood levels return to normal.
Normal thyroxine levels in the bloodstream inhibit TRH release from the hypothalamus and the production of TSH by the pituitary, so normal blood levels are maintained.
role of fsh
releases eggs and sperm
role of lh
ovulation
role of oestrogen
regulation and development of the female reproductive system
role of progesterone
prepares uterus for preganancy
hormonal contrception
oestrogen or progesterone pill inhibit the production of fsh so eggs cannot mature
how is HIV transmitted
sexually
effect of HIV on the immune system
destroys cd4 cells
flu like symptoms
seizures
infection
hypertension
aches and pains
what is thyroxine
Thyroxine is produced from the thyroid gland, which stimulates the metabolic rate. It controls the speed at which oxygen and food products react to release energy for the body to use. Thyroxine also plays an important role in growth and development. Its levels are controlled by negative feedback.
Allelic genes are located on
homologous chromosomes
functions of bile
emulsify lipids so there is a larger surface area for liapse enzymes to work on
neutralise hydrochloric acid from the stomach(this raises the pH)
does bile contain lipase
no
what do leaves do
evaporation of water
formation of organic substanes from inorganic
absorption of oxygen and carbon dioxide
absorption of sunlight
Which of the following statements about selective breeding are true?
Domesticated animals cannot be used for work nor food.
Desirable characteristics in animals may be genetic.
The probability of infectious diseases increases in animals as they are selectively bred.
2 and 3 (same genetics, same vunerability)
What makes tertiary proteins different from secondary proteins
Secondary proteins don’t have ionic and disulfide bonds, whereas tertiary do.
is tRNA invovled in transcription
no
is dna involved in translation
no
true or false: Treatment with stem cells is associated with an increased risk of cancer development
true
where do spindle fibres attatch to the chromosme
at the centromere
reverse transcriptase
does reverse transcription by turning mRNA into DNA
what does restriction endonuclease do
removes the wanted gene from dna
what does dna ligase do
forms recombinant dna by joining plasmid and the gene
a protein tertiary structure is held together by
1 Instantaneous dipole induced forces
2 Ionic interactions
3 Hydrogen bonding
4 Disulfide bridges
what method was used to study downs syndrome
cytogenic (chromosomes)
can conduction and convection happen at the same time
yes
does density of a fluid increase or decrease as the temperature increases
decreases
when the fluid increases in temperature, its particles gain kinetic energy and move faster. This means they move further away from each other, so the density of the fluid decreases.
can a convection current be set up by heating the fluid at the top of a container
no must be the bottom
hw do viruses replicate
Attach to a host cell using attachment proteins. Inject nucleic acid into the host which provides the host’s cells with ‘instructions’ for the cell’s metabolic processes.
the acceleration of an object is directionally proportional to
the resultant force on the object, and inversely proportional to the mass of the object.
Lipids must be emulsified by bile salts produced by the pancreas. true or false
false bile salts are produced by the liver not pancreas
what is emulslification
the breakdown of large fat molecules into smaller, soluble molecules.
Lipase hydrolyses the ester bonds between the
monoglycerides and fatty acids within lipids. Lipids do not have disulfide bonds between them which are hydrolysed.
what holds together the monoglycerides and fatty acids within lipids
ester bonds which are hydrolysed by lipase
is fat absorbed in the stomach
no, and absorption is not limited by less acidic conditions
proton pump inhibitors ______ acid secretion and therefore ______ pH
reduce
increase
if there’s less acdi in the stomach
protein breakdown is prolonged as it is broken down by enzymes that work optimally in acidic condiitons in the stomach
where are carbohydrates absorbed
small intestine. absorption is not facoured by less acidic conditions
is mitosis used in cell growth
no
does asexual reproduction invovle mitosis
yes
does mitosis involve the formaiton of bivalents
no, meiosis does
whats a community
The range of populations present
is cellulose a macromolecule
yes
what is bronchitis
inflammation of the bronchus
what is emphysema
walls of the alveoli are destroyed which reduces the surface area of the lungs and gas exchange
what monomers is dna made from
nucleotide monomers. the nucleotide contains: a phosphate group, a pentose sugar and a base.
what is apoptosis
programmed (and carefully controlled and regulated) cell death. mutations in proteins responsible for apoptosis can lead to cancer
where is amylase produced
mouth and pancreas
where is lipase produced
pancreas and stomach
where are protease produced
stomach, pancreas and small intestine
production of transgenic plants
use of restirction enzymes to produce sticky ends in the plasmid
isolation of the required genes using restriction enzymes
mixing of the required gene an the plasmid with ligases
identification of the recombinant plasmid
injection of plasmid into host plant cell
Anti-coagulants are
life-long medications used to manage CVD.
Statins are medications that
reduce cholesterol. While they may reduce risk of heart attacks in other areas of the heart long term, they will not stop cell death in this area.
A stent is
a surgical procedure that would open up the infarcted artery at the region of cell death, allowing the area to receive blood once more.
do smaller particles diffuse faster
yes
most genetically modified plants are created by
bacteria which have a Ti plasmid
plants having pest resistanace can be a property of
gm crops
The useful gene is inserted into the plant cell chromosomes by
the what plasmid
Ti plasmid - not the Ui plasmid.
what is haemolysis
red blood cells are fragmented. Their components are then recycled. This process takes place in the spleen.
The direction of biotechnology, in which microorganisms are used to obtain antibiotics, vitamins, is called
microbiological synthesis
which side of the heart does deoxygenated blood flow through
the right side
blood from the vena cava enters a
top chamber which is an atrium
what does the pumonary artery carry
deoxygenated blood
frequency increases with…. and decreases with….
increases with energy and decreases with wavelength
wavelength is inversely proportional to
frequency
when temperature is increased, what is the effect on proportion of collisions which are successful
increases
what is the unit of current
I= p/v so watt per volt
Insulin is a protein involved in the regulation of human blood glucose levels.
Genetic engineering can be used to allow the large-scale production of human insulin. how?
Taking the insulin gene from a human chromosome and inserting it into the DNA of a bacterium. As the bacterium reproduces, it makes large quantities of insulin that can be used to treat human diabetes.
should you cool down water from the top middle or bottom
top in the hopes of forming a convection current
Emulsification by bile makes
smaller lipid droplets, each with a smaller surface area. (but larger total SA)
what does bile do to the pH of the stomach
it is alkali so it neutralises the acid making the pH higher
is lipase present in bile
no
properties fo graphene
high mp
good electrical conductivity
