Bits you forget Flashcards
What is a Hormone?
Chemical released into the bloodstream, that travels to a distant site and acts upon a target receptor to cause a particular physiological response
Where is insulin produced?
Pancreas
What does Insulin in the liver do?
Stimulates the liver to turn glucose into glycogen
Things you need to keep the same in the body?
Water, Ions, Blood Sugar, Temp c’ and pH levels
What is Homeostasis?
Maintainance of a constant internal environment
What happens to urine concentration and volume when your in a hot place or excercising?
Sweating more –> Losing More Water
Blood water levels will be lower
High ADH
Reabsorbs more water from urine
Urine Volume is much lower
What Happens when you are too hot?
Sweat –> Evaporates transferring heat energy from the skin to the environment
Vasodilation –> Blood vessles near the skin surface widen, allowing more blood flow to the surface of the skin. This allows more heat to be lost to the environment
Hairs Lie Flat
What happens when you’re too cold?
Very little sweat is produced
Vasoconstriction –> blood vessels near the surface of the skin constrict, reducing blood flow near the surface of the skin helping to reduce the amount of heat lost from the surface of the skin
Shiver –> Increases the rate of respiration because of increased muscle contraction and increased requirement of energy –> Heat energy warms the body
Piloerection –> Hairs stand up –> Trap heat to produce insulating layer around the skin
Do large animals have a high SA:V?
Low SA:V (SO NO)
Do large animals cool down slower or faster?
Cool down slower as they lose heat to surroundings at a slower rate
2 Responses to stimuli?
Geotropism
Phototropism
What are Auxins?
Plant hormones that control growth at the tips of shoots and roots
What is a Shoot’s response to light?
Positively Phototropic
When a shoot tip is exposed to light, it accumulates more auxins on the shaded side than the side in the light
This makes the cells grow (elongate) faster on the shaded side compared to the non-shaded side
This helps to bend the shoot towards the light
(Auxins promote growth in shoots)
What is a Roots response to light?
Negatively Phototropic
Auxins inhibit Growth
If a root starts being exposed to some light, more auxins accumulate on the more shaded side
The auxins inhibits cell elongation on the shaded side, so the root bends downwards back into the ground
Roots that are underground aren’t exposed to light, they grow downwards due to positive geotropism
What is a Chromosome?
Long lengths of DNA coiled up around proteins
Diploid?
Have 2 copies of each chromosome arranged in pairs
Differences between DNA and RNA?
DNA HAS A T C G
RNA HAS A U C G
Thymine is too big to get out of the nucleus
RNA contains sugar
DNA doesn’t contain sugar
What is Meiosis used for?
What is Mitosis Used for?
Making Gametes
Mitosis used for growth and repair
What is the Male Reproductive Part of the Flower?
What is the Female Reproductive Part of the Flower
Stamen (male)
Carpel (female)
What are the Male Reproductive Parts of the Flower
Anther –> Produce male sex cells (pollen grains)
What are the Male Reproductive Parts of the Flower
Anther –> Produce male sex cells (pollen grains)
Filament–> Supports the Anther
What are the Female Reproductive Parts of the Flower?
Stigma –> The top of the female part of the flower which collects pollen grains
Style –>
Ovary –> Produces the female sex cells (contained in the ovules)
Pollination?
Transfer of Pollen from Anther –> Stigma so that the male gametes can fertilise the female gametes in sexual reproduction
Investigating Seed Germination?
Have 4 Test Tubes
1- Water, O2, Temperature
2- No water, O2, Temperature
3- Water, O2, Low Temp
4- Water, no O2, room temp
Tube 1 will grow the most
What are two ways of Asexually producing plants?
Runners –> Only works in Strawberry plants
Fast growing stems that grow out sideways just above the ground which take root at various points
(Short distance away from parent plant to form new genetically identical plants)
Artificial Cutting –> Take cuttings from good parent plants and planting them to produce genetically identical copies of the parent plant
What does Oestrogen do in woman?
Breasts develop
What does the Corpeus Luteum produce?
Produces Progestorone which maintains the lining of the uterus
HCG allows the Corpus Luteum to survive
What does Amniotic Fluid do?
Protects the embryo against knocks and bumps
How is a carrier represented on a family tree diagram?
Half Shaded
What is Population?
All the organisms of one species in a habitat
What is an Ecosystem?
All the organisms living in a particular area and all the non-living conditions
What is Biodiversity?
The Variety of different species on Earth or in an ecosystem
How to use a Quadrat to find the population of X?
Use Random Number Generator to pick coordinates in which you will place your quadrats
Count all the organisms of interest within a quadrat and repeat multiple times.
Work out the mean number of organisms per quadrat (1st sample area)
Repeat step 1 to 3 for 2nd sample area and finally compare the 2 means
Estimate Population size by scaling up
How to study the Distribution of Species in an environment?
Use Bell Transect to study the distribution across a habitat
Mark out a line in the area you want to study
Collect data using Quadrats which are placed next to each other
Count Number of organisms of interest/ or measure abiotic factor (pH) at each Quadrat
Measure the mean number of Organisms in each Quadrat or the percentage cover when appropriate’
Plot the Graph to see if changing abitiotic factors is correleated with a change in the distribution of species you are studying
Producers?
Organisms which make their own food using energy from the sun
How is energy lost in a trophic level?
Staying Alive
Some parts of food are indigestible so pass through the organism as faeces
What are the 4 types of Bacteria involved in the nitrogen cycle?
Decomposers –> Break Down Proteins and Urea into Ammonium Ions
Nitrifying Bacteria –> Ammonium Ions –> Nitrates (Nitrification)
Nitrogen Fixing Bacteria –> N2 –> Nitrogen compounds taken up by plants
Denitrifying Bacteria –> Nitrates –> N2
Where is Sulfur Dioxide formed from?
Sulfur Impurities from fossil fuels
What is the Greenhouse effect?
Greenhouse Gases (H2O, Methane Gas,Co2)
Build up of these gases in the atmosphere that causes the greenhouse effect
These gases trap heat within the atmosphere hezating up the Earth
Man made Sources of Methane?
Cattle Farming
Rice Farming
What does Deforestation lead to?
Leaching –> When trees are removed, nutrients gets leached away but don’t get replaced leaving the soil infertile
Soil Erosion –> Tree Roots hold the soil together when trees are removed. Soil can be washed away by rain leaving an infertile ground
Global Warming
Disturbs Evapotranspiration
