deginitions from whole spec Flashcards
define gene pool
total number of all the alleles in a population at one time
define population
all organisms of one species in a habitat at one time
what does p^2 represent in the hardy weinberg equation
homozygous dominant genotype
what does 2pq represent in the hardy weinberg equation
heterozygous genotype
what does q^2 represent in the hardy weinberg equation
homozygous recessive genotype
define the term species
a group of similar organisms which reproduce to produce fertile offspring
what type of bond is between adjacent nucelotides
phosphodiester bonds formed by a condensation reaction
define biomass
total mass of living material/ carbon is a specific organism/tissue/ area
explain what is meant by climax community
a stable community where there is no further succession
explain what is meant by succession
a change in community over time due to a change in either biotic/ abiotic factors
define hydrolysis
a reaction that breaks a chemical bond between 2 molecules and uses a water molecule
define a condensation reaction
a reaction that forms a chemical bond between 2 molecules and eliminates a water molecule
What is the difference between intermolecular forces and intramolecular forces
intermolecular forces act between molecules and intramolecular forces act within molecule
key theories for the mass flow hypothesis
- active process which requires ATP
- water moves in and out of the phloem by osmosis
- pressure moves the sucrose solution
structures of xylem tissues
- no end walls so water can flow continuously through
- lignin walls to strengthen
- no organelles so less obstruction for water flow
- pores. in cellulose cell wall allowing lateral movement of water to adjacent leaf cells
How does light affect transpiration rate
stomata open when its light so CO2 diffuses in for photosynthesis. Faster transpiration rate
When its dark the stomata close so there is little transpiration
How does temperature affect transpiration
Higher temp= faster transpiration
Warmer water molecules have more energy so they evaporate from the cells inside the leaf faster.
Increases wp gradient inside and outside leaf.
Water diffuses out of the leaf faster
How does humidity affect transpiration
Lower humidity= higher transpiration
If air around plant is dry, water potential gradient between leaf and air is increased
adaptations of alveolar epithelium
- many alveoli so large surface area
- walls of alveoli one cell thick so short diffusion distance
- walls of alveoli have flattened cells so short diffusion distance
- alveoli close to capillaries so short diffusion distance
- alveolar wall is permeable to gases s ventilation maintains diffusion gradient
- alveolar wall is lined with fluid so gases are absorbed
adaptations of xerophytes
- stomata in sunken pits so they are sheltered from the wind to reduce transpiration
- less leaves, spines instead to reduce surface area
- stomata only open at night to reduce transpiration
what is meant by the term diuresis
an increase in the production of urine by the kidney resulting in a large volume of dilute urine
what bonds are between RNA
phosphodiester bonds
what bonds are in a triglyceride
ester bonds
what kind of bonds are there in haemoglobin
peptide bonds
