Biology 2

Question 1

Explain what family studies focus on

Answer 1

Genetic similarity correlated with similarity on a trait

Question 2

Explain what adoption studies focus on

Answer 2

People adopted early in life, genetic or environmental influences.

Question 3

Explain what twin studies focus on

Answer 3

Trait similarities in monozygotic and dizygotic twins.

Question 4

What is selective breeding?

Answer 4

Increasing numbers of that species sharing desired traits

Question 5

Explain natural selection.

Answer 5

Aka ‘survival of the fittest’ environment contributes to shaping genetic expression. Characteristics

Question 6

What are adaptations for?

Answer 6

Enhancing survival.

Question 7

What do neurons consist of?

Answer 7

Three main parts:

• cell body = materials needed to sustain neuron, how it develops and functions
• dendrites = collect incoming info, send info to cell body
• axon = conducts electrical impulses I.e. Info

Question 8

What types of neurons are there?

Answer 8

Sensory; found in skin, muscles, joints and organs, info about stimuli
Motor: stimulate muscle cells
Inter-neurons: connections, CNS

Question 9

Explain information exchange in neurons

Answer 9

Relies on electrical and chemical processes. Has electrical resting potential of -70 millivolts. When stimulated by incoming info, polarity changes to +40mV. This transmits the incoming info or action potential down the axon to the next neuron, muscle or gland.

Question 10

Explain the five steps enabling action potentials in neurotransmitters.

Answer 10

1. Transmitter molecules formed inside the neuron (synthesis)
2. When stimulated by an action potential molecules released in to the synaptic space
3. Cross the synaptic space
4. Bond to receptor sites
5. Molecules continually excite or inhibit the neuron until deactivated

Question 11

What are the major brain divisions?

Answer 11

• Hindbrain
• Reticular formation
• midbrain
• forebrain

Question 12

Explain the hindbrain

Answer 12

Involves the instinctive functions necessary for survival.
Brain stem which includes the:
- medulla oblongata = basic survival functions such as respiration, swallowing, vomiting, heart rate, coughing, sensory and motor nerve tracts. Serves as a gateway for facial sensory and motor nerve tracts
- pons ‘bridge’ = nerve impulses, regulation of sleep and respiration, sending information to/from higher/lower regions of the NS.

Question 13

Explain reticular formation

Answer 13

Located deep within the mid and hindbrain. It alerts higher regions of incoming information acting as a gateway. Involved with attention, sleep and consciousness. Two subsystems:

• ascending arm (reticular activating system) = info to higher regions of the brain to alert it to incoming stimuli
• descending arm = admits or blocks out sensory input from the cerebellum and sensory nerves.

Question 14

Describe the cerebellum.

Answer 14

AKA ‘little brain’, the cerebellum involves coordination of movement, learning and memory. It works independently and unconsciously, damage to it can be life threatening. Damage can result in head tilt, balance problems, loss of smooth compensatory eye movements.

Question 15

Explain the midbrain

Answer 15

Located towards the centre of the brain. Made up of several structures such as tectum, tegmentum and substantia nigra. There are two swellings on each side of the tectum;

• superior colliculus = important for visual processing.
• inferior colliculus = important for auditory processing.

Question 16

Explain the forebrain.

Answer 16

The forebrain consists of:

• thalamus ‘inner chamber’ = interacts with the midbrain, organised and sends information. Receives different inputs from the PNS. Acts as a ‘relay’ centre. Sends most sensory info to cerebral cortex except sense of smell.
• hypothalamus (below the thalamus) = influences motivation and emotion, interconnected with the pituitary gland. Involved with temperature regulation, blood pressure, glucose levels and reward. The 4 F’s: fighting, fleeing, feeding, fornicating. Involved with hormone regulation in conjunction with the pituitary gland.

Question 17

Explain the limbic system.

Answer 17

Limbic system is within the forebrain. It consists of:

• amygdala ‘almond’ = motivation and emotional response patterns, ‘fight or flight’ centre of the brain, interconnected with the hippocampus. Paired association between emotions and objects. Processes fear responses, facial emotions and responds to fearful faces.
• hippocampus = memory encoding and retrieval. Important for consolidating ST memories into LT memories. Declarative and spatial memory. Has connections with the cerebral cortex, damage to this region can result in severe memory impairments.
• basal ganglia = important for planning and producing movement. Collection of nuclei including caudate nucleus, putamen, globus pallidus, nucleus accumbens. Implicated in movement disorders such as Parkinson’s and Huntington’s. damage can result in impaired motor learning. Nucleus accumbens involved with reward.

Question 18

What do Broca’s area and Wernicke’s area involve?

Answer 18

Broca’s: speech formation, situated in frontal lobe.

Wernicke: speech understanding

Question 19

Explain FPOT.

Answer 19

Frontal = reasoning, motor skills, higher level cognition, expressive language and personality. Contralateral. Primary motor
Parietal = sensory info relating to pressure, touch, pain. Primary somatosensory cortex. Involved with visual-spatial processing, damage to right parietal lobe result in hemineglect (ignore left side of visual info).
Occipital: visual stimuli and info, primary visual.
Temporal: primary auditory cortex and hippocampus. Important for mem functions.

Question 20

Explain PNS

Answer 20

Somatic nervous system: voluntary muscle activation
Autonomic nervous system: involuntary muscle activation, consisting of sympathetic nervous system and parasympathetic nervous system.

Question 21

Explain CNS

Answer 21

Spinal cord - neurons enter and leave the CNS, reflexes can be triggered without brain involvement.
The brain - most complex structure in the human body, coordinates neural signals, insufficient energy impacts brain function .

Question 22

What are the four types of nerves?

Answer 22

Cranial: from brain to eyes, mouth, ears, and other parts of head.
Central: in your brain and spinal cord.
Peripheral: go from your spinal cord to your arms, hands, legs and feet.
Autonomic: spinal cord to lungs, heart, stomach, intestines, bladder and sex organs.

Question 23

What do the nervous system and endocrine system have in common?

Answer 23

Both of them transmit info between different areas of the body. They often work together, neural impulses enable fast response and hormone allows sustained reactions.

Question 24

What does endocrine system involve?

Answer 24

Hormone secreting glands, chemical messengers, prolonged activation of systems. Involved hypothalamus, pineal body, pituitary, heart, thyroids, adrenal glands, kidneys and reproductive organs in sexes.

Question 25

What is neural plasticity?

Answer 25

Ability of neurons to change in structure and function. Allows the brain to heal or compensate. Synapses disappear over time, pruning. New connections based on experiences

Question 26

What increases neural plasticity?

Answer 26

Stimulating, supportive environments help foster neural plasticity. Regular and prolonged activation of areas of the brain result in increased size and plasticity. Brains are literally shaped by environments and life experiences.

Question 27

How are men and women different in terms of brain function?

Answer 27

Males are cantered within left hemisphere, women shared between left and right