SciOly Prep- Life Science

What are the two main parts of the nervous system?

The Central Nervous System (CNS) and the Peripheral Nervous System (PNS).

What does the Central Nervous System (CNS) consist of?

The brain and spinal cord.

What is the primary function of the brain?

It serves as the control center for all bodily functions, including thinking, breathing, moving, and feeling.

How many neurons approximately compose the human brain?

About 86 billion neurons.

What are gyri and sulci in the brain?

Gyri are ridges, and sulci are shallow grooves on the brain's surface.

What is the largest part of the brain and its primary functions?

The Cerebrum, responsible for thinking, memory, voluntary movement, conscious thoughts, and actions.

What are the four lobes of the Cerebrum?

Frontal, Parietal, Temporal, and Occipital.

What functions are associated with the Frontal Lobe?

Thinking, emotions, judgment, self-control, and movement.

What is the role of the Parietal Lobe?

Processes touch and integrates sensory information.

What does the Temporal Lobe manage?

Emotions, sensory processing, memory, and language comprehension.

What is the primary responsibility of the Occipital Lobe?

Processing vision.

What functions does the Insular Lobe serve?

Taste, sensory-motor processing, and risk-reward behaviors.

What is the function of the Cerebellum?

Responsible for balance and coordination.

What does the Brainstem control?

Automatic functions like breathing, heartbeat, and digestion.

What is the Limbic System involved in?

Emotions and memory, including structures like the hippocampus and amygdala.

What is the Cerebral Cortex and its functions?

The outermost layer of the cerebrum responsible for higher-level cognitive functions such as memory, thinking, reasoning, and sensory processing.

What is an EEG and its purpose?

An EEG (Electroencephalogram) records electrical activity in the brain to study brain activity, check for seizures, diagnose sleep disorders, and understand attention levels.

What are the different types of brain waves and their associated states of consciousness?

Alpha (relaxation), Theta (light sleep), Beta (focus), Delta (deep sleep).

What is a neural impulse?

A fast electrochemical signal that travels through a neuron, enabling communication between nerve cells and the body.

What are the main components of a neuron?

Dendrites (receive signals), cell body (soma), axon (carries impulse), and axon terminals (send signals).

What is the function of the myelin sheath?

It insulates the axon and speeds up impulse transmission.

What are the types of neurons and their functions?

Sensory neurons carry signals from the body to the brain, motor neurons carry signals from the brain to muscles, and interneurons connect neurons within the CNS.

What is the resting membrane potential of a neuron?

About -70 mV.

What occurs during depolarization in a neuron?

Na⁺ rushes in when the threshold potential (around -55 mV) is reached.

What is a synapse?

The small gap between neurons where communication occurs via neurotransmitters.

What is the difference between chemical and electrical synapses?

Chemical synapses use neurotransmitters, while electrical synapses allow direct ion passage.

What are the key neurotransmitters and their functions?

Acetylcholine (muscle movement), Dopamine (reward), Serotonin (mood), GABA (inhibitory), and Glutamate (excitatory).

What is the role of agonists and antagonists in neurotransmitter function?

Agonists increase neurotransmitter effects, while antagonists decrease them.

What structures protect the CNS?

The skull, vertebrae, meninges, and cerebrospinal fluid (CSF).

How is the spinal cord organized?

The spinal cord is organized into gray matter (inside) and white matter (outside).

What is the function of reflex arcs?

Reflex arcs involve a sensory receptor, sensory neuron, interneuron, motor neuron, and effector for rapid, automatic responses.

What are the components of the Brainstem and their functions?

The Midbrain (visual/auditory reflexes), Pons (connects cerebrum/cerebellum, regulates breathing), and Medulla Oblongata (controls heartbeat, breathing, digestion).

What is the role of cranial nerves?

Cranial nerves (12 pairs) emerge directly from the brain and control functions of the face, head, neck, and some internal organs.

What is the function of cerebrospinal fluid (CSF)?

CSF cushions the brain and spinal cord, circulates nutrients, and removes waste.

What is the importance of sleep for the brain?

Sleep is essential for brain waste clearance, memory processing, and body repair.

What does the Peripheral Nervous System (PNS) consist of?

The PNS consists of nerves outside the CNS, connecting it to the limbs and organs.

What are ganglia in the PNS?

Ganglia are clusters of neuron cell bodies in the PNS that act as mini processing stations.

What is the difference between sensory neurons and motor neurons?

Sensory neurons bring signals into the CNS, while motor neurons send signals out from the CNS to muscles and glands.

What are the two divisions of the Autonomic Nervous System (ANS)?

The Sympathetic division ('fight or flight') and the Parasympathetic division ('rest and digest').

What is proprioception?

Proprioception is the body's sense of its position in space, utilizing receptors in muscles, joints, and the inner ear.

What are the classes of hormones?

Steroid hormones (lipid-derived, insoluble in water), Amine hormones (derived from amino acids, water-soluble), and Peptide hormones (polypeptide chains, water-soluble).

How do water-soluble hormones act on target cells?

Water-soluble hormones bind to cell membrane receptors, initiating a signal transduction pathway.

How do lipid-soluble hormones affect target cells?

Lipid-soluble hormones pass through the cell membrane and bind to cytoplasmic or nuclear receptors, directly affecting gene transcription.

What are the effects of hyposecretion and hypersecretion of hormones?

Hyposecretion (too little hormone) and hypersecretion (too much hormone) can lead to dysfunction.

What condition results from insulin hyposecretion or resistance?

Diabetes Mellitus, leading to high blood glucose levels.

What are the effects of Growth Hormone imbalances?

Dwarfism (hyposecretion) or gigantism/acromegaly (hypersecretion).

What hormones do the Thyroid and Parathyroid glands produce?

The Thyroid Gland produces T3, T4 (regulating metabolism) and calcitonin (lowers blood calcium); the Parathyroid Glands produce PTH (raises blood calcium levels).

What hormones do the adrenal glands produce and what are their functions?

The adrenal glands produce cortisol and aldosterone (cortex) for stress response and salt balance, and epinephrine/norepinephrine (medulla) for fight-or-flight.

What hormones are produced by the pancreas and their effects on blood glucose?

The pancreas produces insulin (lowers blood glucose) and glucagon (raises blood glucose).

What are the functions of sex hormones produced by the gonads?

The gonads (ovaries and testes) produce sex hormones like estrogen, progesterone, and testosterone for reproduction and sexual maturity.

What is the role of the pineal gland?

The pineal gland produces melatonin, which regulates sleep-wake cycles.

What is the function of thymosin produced by the thymus?

Thymosin is essential for T-cell development.

What is Diabetes Mellitus and its types?

Diabetes Mellitus involves high blood glucose due to insulin issues, with Type 1 being autoimmune and Type 2 being insulin resistance.

What is hypoglycemia and what causes it?

Hypoglycemia is dangerously low blood sugar, often caused by excess insulin or missed meals.

What is Graves' Disease and its effects?

Graves' Disease is autoimmune hyperthyroidism causing weight loss and rapid heart rate.

What are the symptoms of Hashimoto's Disease?

Hashimoto's Disease is autoimmune hypothyroidism causing weight gain and fatigue.

What is a goiter and what causes it?

Goiter is an enlargement of the thyroid gland, often due to iodine imbalance or other thyroid conditions.

What is cretinism and its effects?

Cretinism is congenital hypothyroidism causing stunted growth and cognitive delays.

What is Cushing's Syndrome and its symptoms?

Cushing's Syndrome involves excess cortisol, leading to symptoms like moon face and obesity.

What is Addison's Disease?

Addison's Disease is adrenal insufficiency causing fatigue and hyperpigmentation.

What is myxedema and its potential consequence?

Myxedema is severe adult hypothyroidism, potentially leading to coma.

What is acromegaly and its effects?

Acromegaly is excess Growth Hormone in adults, causing enlarged hands, feet, and facial features.

How can sensory receptors be classified?

Sensory receptors can be classified structurally (e.g., free nerve endings), locationally (interoceptors, proprioceptors, exteroceptors), and functionally (thermoreceptors, photoreceptors, mechanoreceptors, chemoreceptors, nociceptors).

What do mechanoreceptors respond to?

Mechanoreceptors respond to mechanical forces like pressure and vibration, crucial for touch, proprioception, and hearing.

What is the function of thermoreceptors?

Thermoreceptors detect temperature changes and help regulate body temperature.

What do nociceptors detect?

Nociceptors detect pain stimuli, signaling injury and protecting tissues.

What is the role of photoreceptors in the eye?

Photoreceptors (rods and cones) in the retina detect light and color, enabling vision.

What do chemoreceptors detect?

Chemoreceptors detect chemical stimuli, playing a critical role in taste and smell.

What information do proprioceptors provide?

Proprioceptors in muscles, tendons, and joints provide information about body position, movement, and balance.

What distinguishes general senses from special senses?

General senses are scattered throughout the body and provide information about touch, pressure, pain, temperature, and body position, while special senses are clustered in specialized head organs and provide detailed information about vision, hearing, balance, smell, and taste.

What are the main structures of the eye and their functions?

The eye contains protective structures (eyebrows, eyelids, eyelashes), three main layers (fibrous layer, vascular layer, inner layer), and processes visual information rapidly.

How does sound travel through the ear?

Sound waves are collected by the pinna, travel through the auditory canal, vibrate the eardrum, and are amplified by the ossicles before reaching the cochlea.

What structures in the vestibule detect linear acceleration and head position?

The utricle and saccule.

What do the semicircular canals detect?

Rotational movement.

How does the nose detect smell?

Airborne molecules dissolve in mucus, bind to olfactory receptors, and send signals via the olfactory nerve to the brain.

What are the five basic tastes?

Sweet, salty, sour, bitter, and umami.

What are common vision disorders?

Myopia, hyperopia, presbyopia, nyctalopia, astigmatism, conjunctivitis, and color blindness.

What are common ear disorders?

Otitis media and types of deafness (conductive and sensorineural).

What are the disorders related to smell and taste?

Anosmia/dysosmia (loss/distortion of smell) and dysgeusia (altered taste).

What is genetics?

The study of genes, their inheritance, and variation, which drives biological diversity.

Who is known as the father of genetics?

Gregor Mendel.

What is a chromosome?

The largest unit of genetic material.

What does ploidy refer to?

The number of chromosome sets in a cell.

What is the difference between diploid and haploid cells?

Diploid cells have two sets of chromosomes, while haploid cells have one set.

What is a gene in Mendelian genetics?

A heritable trait.

What is an allele?

A different form of the same gene.

What does genotype refer to?

The full hereditary information of an organism.

What does phenotype refer to?

The observable physical trait of an organism.

What does Mendel's Law of Dominance state?

A dominant allele produces a visible phenotype with one copy, while a recessive allele requires two copies.

What is the purpose of a pedigree?

To analyze how traits are inherited through multiple generations.

What do Punnett squares illustrate?

All possible genotype combinations in offspring.

What does Mendel's Law of Segregation state?

Each parent contributes one allele to their offspring.

What is genetic linkage?

When genes are on the same chromosome and inherited together.

What is the significance of crossing over during meiosis?

It can separate linked genes, creating new combinations of alleles.

What are sex-linked traits?

Traits carried on the X chromosome, affecting males more often due to their single X chromosome.

What is the structure of DNA?

DNA is a double-stranded, antiparallel molecule forming a double helix, with a sugar-phosphate backbone and nitrogenous bases (A, T, C, G) held by hydrogen bonds.

What does Chargaff's Rule state about DNA base pairing?

Chargaff's Rule states that in DNA, the quantity of adenine (A) equals thymine (T), and guanine (G) equals cytosine (C).

What are proteins composed of?

Proteins are composed of amino acid chains (polypeptides) that fold into specific 3D structures, determining their function.

What is the Central Dogma of Biology?

The Central Dogma of Biology describes the flow of genetic information: DNA → RNA → Protein.

What is the process of DNA replication?

DNA replication is a semiconservative process where each new DNA strand consists of one old and one new strand.