plants and animal responses qp1 and 3 PMT Flashcards
What part of the brain, if damaged, can result in paralysis of the body below the neck
the medulla oblongata
when looking at responses of plants by applying volumes of hormones, what variables must be controlled to produce valid results
-same volume of solution should be applied
-plants should be same age/ height/mass/ genotype/ species
-same watering regime
-same light intensity
-same feature of growth medium (pH/ minerals/ ions)
what type of molecule forms ion channels
protein
what is the enzyme called that is found in the synaptic cleft
acetylcholine esterase
what are the 3 ways to make ATP
-anaerobic respiration
-aerobic respiration
-creatine phosphate
*
what is the role of the cerebrum
controls:
-conscious thought
-conscious actions
-emotional responses
-intelligence, reasoning, judgement and decision making
what is the role of the cerebral cortex
contains: -sensory areas, -association areas, -motor areas.
-sends action potentials to various effectors (muscles and glands)
-motor areas on the left side of the brain control effectors on the right side of the body.
-coordination of muscles involved in walking
-coordination of muscles to bend elbow joint
-conscious decision to contract voluntary muscles
what is the role of the cerebellum
-coordination of movement and balance
-receives input from many sensory receptors (e.g. retina, balance organs in inner ear, spindle fibres in the muscles
what is the role of the medulla oblongata
-controls non-skeletal muscles
-involved in paralysis
-sends action potentials through autonomic system
-contains 3 centres:
-cardiac centre
-respiratory centre
-vasomotor centre (regulates circulation and blood pressure)
what is the role of the hypothalamus and pituitary complex
-controls homeostatic mechanisms
-temperature regulation: detects changes in core body temperature. (mediated by nervous or hormonal system)
-osmoregulation- hypothalamus contains osmoreceptors that monitor water potential in the blood. (mediated my hormonal system and pituitary gland)
-produces releasing factors which causes the anterior lobe to produce its own hormones. Responses to stress, growth and lactation
compare the parasympathetic system (P) with the sympathetic system (S)
Parasympathetic system
-long preganglionic neurone
-acetylcholine
-rest/ relaxion
-decreases heart rate
-reduces speed/ rate of breathing
- reduces airway diameter
-increases flow to the gut
-sexual arousal
-constricts pupils
-makes liver take up more glucose
Sympathetic system
-short preganglionic neurone
-noradrenaline
-fight/ flight
-increases heart rate
-increases depth of breathing
-increases airway diameter
give two reasons why both plants and animals need to be able to respond to their environment
-to avoid (abiotic) stress
-to access resources
-to prevent being eaten
state three differences in the ways in which plants and mammalian hormones operate
-hormones in animals travel in the bloodstream while in plants they move in the xylem or phloem
-hormones made in endocrine gland, plant hormones made in many plant tissues
-hormones act on few/specific target tissues in animals vs in plants where they act on most tissues/ act in cells where they are produced
-animal hormones act more rapidly
lack of a growth hormone can cause dwarfism, explain why dwarfism is a genetic condition
-its inherited/ passed onto offspring/ passed down from parents
-caused by mutation
describe examples of genes being switched on or being switched off by a molecule that binds directly to DNA.
- A repressor protein changes shape when bound to lactose, it then lifts off the operator region allowing transcription/ gene expression/ binding of RNA polymerase to promotor. Transcription of B-galactosidase/ lactose permease
-homeotic/ homeobox/ hox genes. Transcription factor/gene product/protein binds to DNA, gene product starts transcription. Many genes are affected/ controls body plan
-steroid hormones can diffuse through the cell surface membrane and nuclear membrane, the hormone then binds to DNA and switches genes on and off
how is the nervous system involved in the fight or flight response
-sympathetic motor neurones stimulated
-noradrenaline
-neurotransmitter released at neuromuscular junction
how is the endocrine system involved in the fight or flight response
-adrenaline released into blood
-from adrenal glands/ adrenal medulla
-adrenaline/noradrenaline binds to target receptors
what is the role of voluntary (skeletal) muscle in fight or flight
-breathing/ intercostals contracting/ diagram contracting faster
-more blood flow to skeletal muscles
-skeletal muscles being primed for action
state the term used to describe a directional growth response of a plant
tropism
state the term used to describe a signalling molecule that enables plants to respond to environmental change
plant hormone/growth substance
state the term used to describe a plant that loses its leaves seasonally
deciduous
state the term used to describe the conversion of nitrogen gas to ammonium compounds in the soil
nitrogen fixation
explain why one individual can only have two of the different alleles of a gene
-humans are diploid (2n). Chromosomes are in pairs/ homologous. One copy/ gene/ allele from each chromosome pair
what technique would reveal the differences in the lengths of a gene
electrophoresis
what does electrophoresis do
electrophoresis separates nucleic acid fragments or proteins
explain how a good allele could become common in a population
-natural selection
-selective advantage
-allele increases survival by providing food or find new resources or mate
-allele passed onto next generation
-allele increased in frequency over time
when testing plant hormones on plants, why is it important to keep temperature constant
-so temperature doesn’t affect results
-so only desirable variables are changed
-temperature affects enzyme activity
-suitable/optimum temperature for lettuce germination
when testing hormones on plants, what needs to be kept constant other than temp
-length of time experiment set for
-volume of liquid
-genotype of seeds
state some commercial uses of plant hormones
-seedless fruits
-weed killers
-rooting powder
-control fruit ripening
-controls fruit drop
-restrict hedge growth
-preserve cut flowers
-producing malt in brewing
