Biology Flashcards
what are the 4 factors that affect the rate of photosythesis
light intensity,temperature,concentration of carbon dioxide,chlorophyll
What does chlorophyll do
absorbs light energy needed for photosynthesis
How do the levels of chlorophyll vary within different plants
disease,enviromental stress,lack of nutrients
Why is temperature not as effective when affecting the rate of photosynthesis
because when the enzymes gain to much energy they denature
How do people artifically create conditions that help affect the rate of potosynthesis
in colder climates if you use greenhouses it traps the suns heat which helps increase the temperature and it helps photosynthesis continue through day and night,it will be harder for pests and pathogens to enter the plants
A parrafin heater releases heat and CO2
What is required to produce amino acids from glucose
Nitrates
T or F The compensation point is lower in shade adapted plants than in plants adapted to sunny conditions.
true
What is the compensation point
The compensation point is the light intensity at which the rate of photosynthesis is equal to the rate of respiration of a plant.
Which parts of the electromagnetic spectrum are absorbed by the chlorophyll molecule and why?
Red and blue parts of the electromagnetic spectrum are absorbed by the chlorophyll molecule.The chlorophyll molecule appears green because this is the part of the spectrum it reflects, absorbing blue and red.
In an investigation on photosynthesis, why did a student add sodium hydrogencarbonate to the water?
The student added sodium hydrogencarbonate to the water because it is a source of carbon dioxide for the pondweed in the investigation.
what could best explain why a student studying bubbles of oxygen given off from pondweed obtained a result of 81 in one experiment, and 9 bubbles in a second experiment?
The student moved the pondweed from a distance of 10 cm away from the light source in the first experiment, to 30 cm away in the second
what best explains why a plant breeder placed open bags containing a fungus around his greenhouse?
The fungi will respire and release carbon dioxide into the greenhouse.
What is the definition of cellular respiration
an exothermic reaction which transfers energy from glucose and is continously occuring in living cells
What are the examples of how organisms use their energy
to build larger molecules from smaller ones,muscular contraction,to maintain body temperature
What is the definition of metabolism
all chemical processes that occur within a living organism in order to maintain life
what are the 2 types of respiration
anaerobic and aerobic
Where is aerobic respiration used
in the mitochondria and it is used with oxygen
What is anaerobic respiration and what is the word equation
it is used when our body can’t supply oxygen like running the word equation is Glucose->lactic acid
What are the 2 reasons our body prefers not to use anaerobic respiration
incomplete breakdown of glucose molecule as there is no oxygen to oxidise it,lactic acid builds up and later it has to be removed
What is the word equation for anaerobic respiration in plants and yeast,what is the word equation called for yeast
Glucose->ethanol+carbon dioxide for yeast this process is called fermentation
What is the scientific definition for respiration
a series of biochemical reactions,controlled by enzymes that releases energy from glucose.The process happens inside the cells cytoplasm and special organelle called the mitochondria
describe the process of respiration
blood cells transport the oxygen around the body,when it reaches the mitochondria the oxygen is absorbed,and the glucose in the blood cells is partially broken down in the cytoplasm before it is absorbed by the mitochondria.Once in the mitochondiron the oxygen and glucose react to form water and carbon dioxide and releases energy in the form ATP
What is variation controlled by?
Genes and the enviroment
What are sperm and egg cells also known as
Haploids
What is fertilisation
when sperm and an egg fuse
What are 2 examples of genetic variation
natural eye colour and gender
What is a mutation
A mutation is a change in a gene or chromosome.
What type of change does the peppered moth show?
Natural selection is the change as the moth with the best camouflage survived
Why is selective breeding used with animals or plants?
Genetic diversity is reduced as only desirable characteristics that will be of benefit will be selected, e.g. good quality meat.
What is genetic engineering?
he genome of one organism is altered by adding a gene from another to create a desirable characteristic.
What are clones?
Genetically identical to the parent cell
How are animals cloned?
Animals are cloned by using embryo transplants and adult cell cloning
What is the process of genetic engenering
you find an organism with a desirable characteristic(a plant with lots of fruit)then you take some of the gene and transfer it to another organism so the other organism develops the same trait
T or F when genetically modifing a specie you are only limited to that particular specie
false you can modify other species with it
How has bacteria been genetically modified
to produce the hormone insulin this helps us treat diabetes
How does gene therapy work
if someone or something has faulty genes gene therapy will give a person the healthy version of the gene
What are the problems with gene therapy and what is a possible solution for it
that the faulty gene would be in all of the cells.it is hard to transfer the new cell to every cell in the body the solution would be to transfer the gene at an early stage of development
What are the pros of genetically modified crops
to make them with desirable characteristics(more fruits,resistant to disease)this makes more food for less money,make them produce special nutrients
What are the cons of genetically modified crops
we don’t know how genetically modified crops will affect our health,they could outcompete different plants which would change the entire ecosystem
When genetically modifying things how do we transfer the genes from one place to another
1.Find the gene we want and cut the part of DNA we want of it to isolate it we do this by using enzymes
2.Insert the gene into a vector(a virus or a bacteria plasmid
3.Introduce the vector to any organism we want to have the gene,then it will take in the vector and start producing the protein it is coded for
Why is studying fossils important
because most of the things that ever lived are extinct so the only way we can learn about them is looking at what’s left behind of them,we can see how organisms have changed which helps with evidence for evolution
what are the 3 main ways that fossils can be formed
gradual replacement by minerals,casts+impressions,preservation
explain the fossil form of gradual replacement by minerals
things like shells teeth and bones take a really long time to decay so as they decay they are replaced by minerals making them form rock like substances
explain the fossil form of casts+impressions
we get casts when an organism is burried in a soft like way and as it hardens the organism starts to decay and we are left with a gap which was the same size and shape as the organism was.Impressions are things like footprints where organisms leave a mark on the ground
Explain the fossil form of preservation
this is very rare,it is where no decay happens at all,it happens when organisms get stuck in amber or tar pits and because there is no oxygen or moisture no decay can take place
What is 2 reasons for us not knowing how life first developed on earth
early life forms were soft bodied so they decay very quickly,fossils that were formed long ago may have been destroyed since like volcanoes
What are the reasons for species becoming extinct
the enviroment changes to quickly(habitat getting destroyed),human hunting,disease,new species outcompetes them for food,catastrophic event like an asteroid(dinosaurs)
What is variation caused by?
enviromental and genetic factors