animal + plant responses Flashcards
What can damage to the central nervous system lead to?
Loss of memory, learning, cognition, sight, and hearing due to damage to the cerebral cortex.
What causes loss of balance and coordination?
Damage to the cerebellum.
What functions are affected by damage to the hypothalamus?
Feeding, sleeping patterns, temperature control, and water balance.
What are the consequences of damage to the medulla oblongata?
Loss of swallowing, bladder control, bowel movement, and control of heart and breathing rate.
What happens when there is damage to the neuromuscular junctions?
Lower frequency of action potentials leads to less acetylcholine released, so less neurotransmitter binds to the sacrolemma receptors , resulting in less depolarization of the post-synaptic membrane.
What does the central nervous system consist of?
The brain, spinal cord, and intermediate neurones.
What is the role of the peripheral nervous system?
It responds to the environment by conducting action potentials from sensory receptors to the CNS and from the CNS to effectors.
What are the two parts of the autonomic nervous system?
The sympathetic and parasympathetic nervous systems.
How do the sympathetic and parasympathetic nervous systems differ?
Sympathetic has short preganglionic and long postganglionic neurones; parasympathetic has long preganglionic and short postganglionic neurones.
What neurotransmitter does the sympathetic nervous system use?
Noradrenaline.
What neurotransmitter does the parasympathetic nervous system use?
Acetylcholine.
What is the effect of the sympathetic nervous system during stress?
Increases heart rate, blood pressure, and breathing rate.
What is the effect of the parasympathetic nervous system when at rest?
Reduces heart rate, blood pressure, and breathing rate.
What happens to blood flow in the sympathetic nervous system?
Increases to skeletal muscle and decreases to the gut.
What is the role of ligaments in the human elbow joint?
They hold bones together to prevent dislocation.
What is the function of cartilage in joints?
Reduces friction and wear.
What is the role of the synovial membrane?
Produces synovial fluid to lubricate joints.
What does a stroke cause?
Disruption of oxygen and glucose supply to brain cells for areobic respiration, leading to cell death. which can result in damage to the cerebellum resulting in problems w/ coordination and movement
How does adrenaline affect heart rate?
Increases heart rate and stroke volume.
Where is the cardiovascular centre located?
In the medulla oblongata.
What does the vagus nerve do?
Decreases heart rate.
What is the role of hormones in heart rate control?
They act on the sinoatrial node (SAN) to coordinate heart rate.
How does adrenaline act as a first messenger?
It binds to receptors on target cells, activating a G protein, which activates adenylyl cyclase
What is the cAMP pathway?
A signaling pathway where ATP is converted to cAMP, activating proteins.
What is the advantage of having multiple steps in a signaling pathway?
It allows a small number of molecules to cause large effects.
What functions does the medulla oblongata control?
Breathing, heart rate, circulation, swallowing, salivation, and vomiting reflex.
What is an advantage of reflexes?
They are involuntary and require little thought.
What happens when the terminal buds are removed from a plant?
Side shoots grow due to decreased auxin concentration.
What happens when auxin paste is applied to a plant?
- there is no growth until in the side shoots at first bc the auxin moves out of the paste + inhibits growth
- Growth in side shoots only occurs once auxin has been used up from the paste
Why do plants need to respond to the environment?
To cope with changing conditions
avoid abiotic stress
maximise PS
to obtain more light
to avoid herbivory
What should be controlled in plant investigations?
Temperature, volumes of liquids, oxygen availability, age of seeds, previous storage of seeds , variety of seeds , size of petri dish, length of time experiment left for before recodring results , space between seeds kept the same
What are some commercial uses of plant hormones?
Producing seedless fruits, weedkillers, and controlling fruit ripening.
What are the characteristics of skeletal muscle?
Voluntary, striated, cylindrical, and multinucleate.
What are the characteristics of smooth muscle?
Involuntary, not striated, spindle-shaped, and uninucleate.
What are the characteristics of cardiac muscle?
Striated, branched, uninucleate, with intercalated discs.
Why are monkeys used in studying human brain function?
- They are more closely related to humans as share more genes + more recent common ancestor
- brains have physiology + structure that is more similar to that in humans
- bigger brain that rats so easier to observe
What happens during the fight or flight response?
- Sympathetic motor neurones are stimulated,
- norarenaline neurtrasnittter releases at neuromuscular junctions + organs
- adrenaline is also secreted into the blood from the medulla of the adrenal glands.
- adrenaline + noradrenaline bind completely to complementary receptors on traget tissue
- increasing heart rate and blood pressure.
What are outward signs of the fight or flight response?
Dilated pupils, tensed posture, and raised hackles, teeth bared
What occurs in a relaxed animal?
Slow heart rate, shallow breathing, and good blood flow to the gut.
What occurs in an animal in the fight or flight response?
Fast heart rate, deep breathing, and increased blood flow to skeletal muscles.
in liver glycogen converted to glucose
What neurotransmitter is active in a calm animal?
Acetylcholine.
What neurotransmitter is active in a fight-or-flight animal?
Noradrenaline.
What happens when plants experience overcrowding?
- More auxin is produced, causing positive phototropism.
- so that plants shoots , bend towards the light + plants grow taller
What happens if the top of a plant is eaten?
Auxin production stops+ apical dominance stops, allowing side shoots to grow due to lateral buds developing + plant becomes bushy
What is the role of glycogen granules in striated muscle?
- Energy storage
- as glycogen breaks down to glucose
-which can be used for respiration to make ATP
What changes occur in muscle contraction?
The A band stays the same, the H zone shortens, and the I band shortens.
What happens during strenuous exercise regarding hydrogen ions?
- Increased hydrogen ions reduce calcium binding to proteins in myofibrils
- decreasing muscle contraction force
- as fewer ca ion bind to troponin
- fewer tropinin proteins change shape
- fewer tropomyosin protiens move aside
- fewer binding sides on actin available
- fewer actin-myosin cross brudges form
- power stroke is reduced as acton filaments pulled past mysosin w/ less force as the low pH is denaturing the protiens
How do the biceps and triceps function together?
Biceps contract to bend the arm, trceps relax ; biceps relaxes, triceps contract to straighten it.
What occurs during muscle contraction?
- ATP is hydrolyzed to release energy
- myosin head changed shape + attaches to the actin binding site
- actin is pulled past the myosin
- ATP binds to the myosin head + the myosin head deaches from actin
- ADP + Pi detach from myosin
How is ATP regenerated in muscles?
Using creatine phosphate.
Why is glucose required for skeletal muscle contraction?
- It releases energy to produce ATP
- ATP needed for breaking of cross bridges between myosin + actin
- ATP hydrolysed ti ADP +Pi to reset myosin heads
- ATP used for AT of ca2+ back into arcoplasmic reticulum
What can cause biochemical differences in plants?
Different alleles, enzymes, and plant growth regulators.
How can you test plant hormone levels in different varieties?
- test each variety of a plant , repeast reasding
- Control variables like age, soil type, and light conditions during testing.
- same testung procedure detail - leaf mass, vol of solvent . temp
- measure plant hormone conc - can meausre its conc if its an acid based on pH
What prevents positive phototropism in seedlings?
Lighting them equally from all sides.
Why do animals need to respond to environmental changes?
To avoid abiotic stress, predation, and to access resources.
Why can plants form natural clones more easily than animals?
- Most plant cells retain the ability to differentiate (totipotent) and have meristematic tissue containg stem cells
- plants can de differenciate + then differeciate into a diff cell type
- most animal cells are multipotent and so are only able to differenciate into the same types of cells
How does auxin move in plants?
- From apical cells at the tip of the shoot via the parenchyma by diffusion
- greater auxin conc at shaded sides
- auxin causes cell wall looseing + expansion , allowing shaded side to grow taller , bending the shoot tip towards the light
What happens when light is shone in human eyes?
Receptors on their retina detect light, triggering a nervous impulse along sensory –> intermediate in brain –> motor via synaptic transmission –> depolarisation + contraction of muscle fibres
What is the selective advantage of producing nicotine in plants?
It deters herbivores from eating the plant, so stops loss of leaf area allowing the plant to survive to breed + resproduce seeds
How does the impulse travel from the intermediate neurone to the muscle?
The impulse travels from the intermediate neurone to the motor neurone via synaptic transmission, then from the motor neurone into the muscle across the neuromuscular junction, causing depolarisation and contraction of the muscle fibres.
What is the selective advantage of producing nicotine in plants?
Producing nicotine is selectively advantageous as it stops the plant from being eaten, preventing loss of leaf area, allowing the plant to survive, breed, and produce seeds.
What is the selective disadvantage of producing nicotine in plants?
Producing nicotine is selectively disadvantageous as it decreases reproductive success, resulting in a lower number of seeds due to metabolic resources being diverted to nicotine production.
What is the A band of muscle made of?
The A band of muscle is made of myosin.
Why are chimpanzees stronger than humans?
Chimpanzees are stronger than humans because their arm muscles are the same thickness, but the bones of their lower arm are longer, resulting in longer muscles and more muscle fibres to deliver contracting force.
