Bio general Flashcards
use ideas about atoms ions and the transfer of electrons to explain the formation during electrolysis
one electron moves from ion to anode // ions attracted to anode
How white blood cells defend against disease
Produce antibodies // responsible for phagocytosis // antibodies destroy pathogens
roles of mitosis
growth, repair of damaged tissue, asexual reproduction, replacement of cells
compare direction of movement of substances during translocation and transpiration
transpiration occurs upwards from root to leaf // translocation occurs up and down the plant
role of enzymes in the chemical digestion that occurs in the mouth
amylase breaks down starch // to simple sugars // large insoluble to smaller soluble MOLECULES
differences between selective breeding & natural selection
SB : humans select the desirable features // faster process // results in less variation // inbreeding is more common
effect of ciliated cells dying, on the gas exchange system
alveoli get blocked // reduces area for gas exchange // goblet cells produce mucus // mucus traps bacteria // cilia unable to remove mucus // decreases surface area of gas exchange // bacteria multiply // causing infection // breathing difficulties
why nitrate increases plant growth
nitrate needed to make amino acids
amino acids needed for protein synthesis
proteins are needded for growth which increases the yield
uses of carbohydrates made during photosynthesis
reactant for respiration
to make cellulose for cell walls
converted to sucrose for transport
how skin responds to cold temperatures to maintain constant internal body temp
vasoconstriction // arterioles narrow // blood flow to surface capillaries reduced // less heat lost by radiation // hair stands on end
why is chlorophyll needed for photosynthesis
transfers light energy to chemical energy // to synthesise carbohydrates
features of placenta that enable efficient gas exchange
thin membrane // large surface area // good blood supply // permeable membrane
mitosis vs. meiosis
chromosome produced by MITOSIS have a diploid number
cells produced by MITOSIS contain two sets of chromosomes , are paired / cells produced by MEIOSIS are unpaired
cells produced by MITOSIS are GENETICALLY identical to parent cell
features of alveoli that make them efficient gas exchange surfaces
good blood supply, thin, large surface area, ventilated
difference between artificial selection & natural selection
A - traits selected by humans
- usually chosen for economic reasons ( N : beneficial for survival)
- faster results
- takes place in selected individuals (N takes place in whole populations)
- does not lead to evolution
results in decreased genetic variation
- leads to increased likelihood of genetic disease
pulse rate during exercise
increases,
heart pumps more blood
increase in muscle contraction
muscles need more energy
increase in the rate of respiration
increase in pulse rate to transfer more oxygen
features of artery
thick wall
- withstands high pressure of the blood
narrow lumen
- maintains blood pressure
arterioles when reducing body temp
vasodilation - arterioles widen
increase in blood flow to skin surface
more heat loss from skin by radiation
negative feedback definition
any change results in an opposing action
ref to a set point
discontinuous variation
limited number of phenotypes ;
no intermediates
caused by genes alone
how carbohydrates are transported from leaves to the roots
ref to translocation ;
transported as sucrose ;
through the phloem ;
how metallic elements and non-metallic elements form ionic bonds
metallic elements lose electrons to form positive ions ;
non-metallic elements gain electrons to form negative ions ;
(there is a) strong attraction between (oppositely charged) ions ;
(because of) their opposite (electrical) charges ;
differences between nuclei in games & body cells
gametes have haploid nuclei / body cells have diploid nuclei ;
gametes have unpaired chromosomes / body cells have paired chromosomes ;
gametes have 23 chromosomes / body cells have 46 or 23 pairs ;
why magnesium ions are needed for photosynthesis
magnesium ions required to make chlorophyll ;
chlorophyll absorbs light energy (and converts this to chemical energy) ;
(chemical) energy used to synthesise, carbohydrates or glucose / carbohydrates or glucose are used to make proteins
(for growth) ;
