Notes, summaries, assignments, exams, and exercises for Biology for University

A Minimal pair is a pair of words that vary by only A single sound, usually meaning sounds that may confuse English learners, like The /f/ and /v/ infanandvan, Or the /e/ and /ɪ/ indeskanddisk

Minimal Pairs /ɪ/ and /i:/sit Seat

Minimal Pairs /e/ and /ɪ/desk disk

Minimal Pairs /e/ and /eɪ/wet wait

Minimal Pairs /æ/ and /ʌ/bat but

Minimal Pairs /əʊ/ and /ɔ:/sosaw

Minimal Pairs /ɒ/ and /əʊ/not note

Minimal Pairs /æ/ and /e/bad bed

Minimal Pairs /ɑ:/ and /ɜ:/fast first

Consonant Sounds

Minimal Pairs /b/ and /v/berryvery

Minimal Pairs /b/ and /p/buypie

Minimal Pairs /n/ and /ŋ/thinthing

Minimal Pairs /l/ and /r/alive arrive

Minimal Pairs /ʧ/ and /t/catchcat

Minimal Pairs /s/ and /ʃ/seashe

Minimal Pairs /f/ and /v/fanvan

Minimal Pairs /f/ and /h/

Sensory Receptors and Sensory Nerves

Sensory Receptors

Information from the environment and internal organs is detected by sensory receptors. These receptors can be:

• Surrounded by cells (not neurons)
• Connected with a neuron (sensory nerve) in which they will generate action potentials
• Specialized to respond to one particular form of energy

There are many different types of sensory receptors:

• Mechanoreceptors - detect touch and pressure
• Thermoreceptors - detect cold and warmth
• Nociceptors - detect pain
• Electromagnetic receptors - detect light
• Chemoreceptors - detect taste, smell, blood O₂ and CO₂ concentration, blood glucose, amino acids, and fatty acids

A receptor can be excited by:

• Mechanical deformation - stretches the receptor, opening ion channels
• Application

Plant Photosynthesis: C3, C4, and CAM Pathways

C4 Plants

C4 metabolism has a higher energy cost than C3, requiring 5 ATP and 2 NADPH per CO2 fixed. C4 plants are adapted to tropical, subtropical, relatively dry environments with bright illumination and can withstand high and low relative humidity. They fix CO2 using PEP carboxylase and then pump it to the bundle sheath cells.

C3 Plants

C3 plants use 3 ATP and 2 NADPH and are adapted to temperate climates with moderate temperatures and high relative humidity.

Exogenous Factors Affecting Photosynthesis

• Light
• Concentration of CO2 and O2
• Temperature
• Availability of water and nutrients

Endogenous Factors Affecting Photosynthesis

Type of plant (C3, C4, or CAM), stomatal density, leaf area, leaf age, hormone...

Endoplasmic Reticulum

In all eukaryotes (animals and plants), a complex system of sacs and tanks exists in the cytoplasm, separated by a membrane. This system, the endoplasmic reticulum (ER), covers the entire cell and delimits two non-interconnected spaces: the inside of the ducts and the hyaloplasm. It is part of the cytoplasmic vacuolar system, which also includes the nuclear envelope and the Golgi apparatus.

The ER consists of a series of tubular cavities or tanks, isolated from the cytosol by a membrane. This membrane may or may not be covered with ribosomes, which are responsible for protein and phospholipid biosynthesis. The ER is composed of flattened, stacked vesicles. The rough endoplasmic reticulum (RER) has ribosomes attached to its...

Mendel's Laws of Inheritance and Genetic Crosses

Mendel's Laws of Inheritance

1. Law of Segregation: Each parent contributes only one of their two alleles for a specific trait to their offspring.
2. Law of Independent Assortment: Alleles for different traits are passed down independently of one another during gamete formation.
3. Law of Dominance: When an organism inherits two different alleles for a trait, the dominant allele will be expressed in the phenotype, masking the effect of the recessive allele.

Analyzing Monohybrid Inheritance

Case Study: Earlobes (Monohybrid Cross)

The results of the cross show:

• Mr. Jones: aa (Attached earlobes, recessive)
• Mrs. Jones: Aa (Free earlobes, heterozygous dominant)

Their children exhibit the following genotypes and phenotypes:...

Microbial Secretion Systems

Matching

Which secretion system:

• Moves protein from the periplasmic space to the exterior? 2, 4, 5
• Moves DNA from one cell to another through conjugation? 4
• Moves protein from cytoplasm to exterior (not into another cell)? 1, 3
• Relies on Sec to do the first step of transportation? 2, 4, 5
• Requires ATP? All
• A domain of the protein itself forms a beta-barrel that inserts into the outer membrane (i.e., forming a pore), allowing the rest of the protein to pass through? 5
• The protein being transported carries a C-terminal signal peptide? 1
• The preprotein (before final folding) being transported carries an N-terminal signal peptide? Sec

Viral Multiplication

Six Steps to Viral Multiplication:

1. Attachment to host cell
2. Entry
3. Uncoating of

Cell Membrane Dynamics

Plasma membrane phospholipids are labeled with a fluorescent tag and then the phospholipids in one area are bleached with a laser beam to eliminate the fluorescent signal. What would one observe after the cell is incubated for a few minutes? The bleached molecules would diffuse laterally through the membrane and intermix with unbleached molecules. Cellular membranes are mosaic and fluid. Glycosylated proteins and lipids within the plasma membrane are important for cell recognition and protection.

Passive Diffusion

Passive diffusion is a spontaneous process. Water diffuses through certain organs such as the kidneys and bladder much faster than would occur by passive diffusion through a lipid bilayer alone. What accounts for...

Fibers

• Ia: 10-20 μm / 80-120 m/s / Proprioceptors: Muscle spindles 1, 5, 6, 7, 9
• Ib: 10-20 μm / Proprioceptors: Golgi tendon organ 5-8, 7 - <9
• II: 6-2 μm / 50 m/s / Cutaneous mechanoreceptors + Proprioceptors: Muscle spindle 2º / 3-4, 7
• III: 1-5 μm / 5-30 m/s / Free nerve endings / 1.5, 6 - <9
• IV: 0.5-1.5 μm / 1 m/s / Free nerve endings, cutaneous and visceral / 2

Ascending Pathways of the Spinal Cord

• Posterior Pathway (PP): Integrates multiple segments of the spinal cord, surrounding the substantia gelatinosa.
• Posterior Column Pathway (CP): Fine touch information; Gracile (always) / Cuneate (T7 and above) - Ipsilateral - Medulla - Contralateral
• Spinothalamic Anterior Lateral Pathway (SAL): Crude touch information; Posterior horn - Contralateral

Forensic Aspects of Asphyxia

Carotid Artery Occlusion

Loss of consciousness typically occurs within 10-15 seconds of complete occlusion of the carotid arteries. This timeframe allows for the implementation of restraint mechanisms.

Differential Diagnosis at the Scene

Differential diagnosis is crucial and is made at the scene, considering:

• The victim's clothing state.
• Presence of extracervical lesions indicative of control or struggle.
• Severity of neck injuries.

The diagnosis of accidental etiology is based on a meticulous examination of the scene. A high blood alcohol level may explain the victim's low resistance or the possibility of accidental strangulation.

Forensic Pathology of Submersion (Drowning)

Definition and Types of Submersion

Death or pathological...

Acoustic and Articulatory Classification of Speech Sounds

Places of Articulation (Phonetic Classification)

Sounds are classified based on where the vocal tract is constricted:

• Labial (Lip): Severe and diffuse sound, articulated with the lips.
  • Voiced (Sonoro): (b, m)
  • Unvoiced (Sordo): (p, f)
• Dental: Acute and diffuse sound, articulated with the tongue on the teeth (anterior and coronal).
  • Voiced (Sonoro): (d)
  • Unvoiced (Sordo): (t, s [strident], c [mate])
• Velar (Soft Palate): Serious, thick sound, articulated by striking the tongue against the soft palate (velum).
  • Voiced (Sonoro): (g [as in 'gue'])
  • Unvoiced (Sordo): (k, x [j])
• Palatal: Acute and dense sound, articulated by rubbing the tongue against the hard palate (coronal).
  • Voiced (Sonoro): (ñ, y)
  • Unvoiced