Notes, summaries, assignments, exams, and problems for Biology

Deoxyribonucleic Acid (DNA)

Composition and Structure

• Name: Deoxyribonucleic Acid
• Composition: Deoxyribonucleotides (nucleotides with deoxyribose: Adenine (A), Guanine (G), Cytosine (C), Thymine (T))
• Structure: Outer skeleton with pentose and phosphate, bonded by complementary bases.

Location and Functions

• Location: In the nuclei of eukaryotic cells and the cytoplasm of prokaryotic cells.
• Functions: Controls cell activities and carries genetic information.

Ribonucleic Acid (RNA)

Composition and Structure

• Name: Ribonucleic Acid
• Composition: Ribonucleotides (nucleotides with ribose: Adenine (A), Guanine (G), Cytosine (C), Uracil (U))
• Structure: Single chain of ribonucleotides.

Location and Functions

• Location: In the nucleus and cytoplasm of cells.
• Functions:

Neck Muscles

Longus Colli

O: C3-C5, anterior tubercles of the transverse process; C5-T3, anterior surfaces of bodies; C2-C6, anterior surfaces
I: C2-C6 anterior surface
A: Laterally flexes head and neck, rotates head and neck towards the same side

Sternocleidomastoid

O: Mastoid process
I: 1/3 medial clavicular head
A: Flexes head and neck, laterally flexes head and neck, rotates head and neck to the opposite side

Longus Capitus

O: C3-C6
I: Occipital bone
A: Flexes head and trunk bilaterally

Rectus Capitus Anterior

O: C2 atlas
I: Occipital bone
A: Flexes head and neck

Splenius Capitus

O: Ligamentum nuchae
I: Temporal bone, mastoid process
A: Rotates head to the same side, extends head and neck

Splenius Cervicis

O: T3-T6 spinous processes
I: C2-C3 posterior tubercles
A:

Sepsis Classification

According to Gates of Sepsis

Morphology of Sepsis

• Inflammatory Focus
• Microorganism Entering Bloodstream
• Systematic Change in Immune System

Bacteremic Toxic Shock

Syndrome induced by an abundant amount of toxins and biologically active substances released into the bloodstream by bacteria and injured tissue cells.

Morphological Features

• Disseminated Intravascular Coagulation
• Hemorrhagic Syndrome
• "Empty Heart"
• "Shock Kidney"
• "Shock Lungs"

Cyclic Infection

• Exoinfection (autonomous disease)
• Etiology: Obligatory Pathogenic
• Specific Immune Response
• Immunity Develops

The Cell Cycle

The cell cycle consists of two main phases: interphase and mitosis (M phase) [3].

Interphase

Interphase is further divided into three phases:

1. G1 phase (Gap 1): During this phase, the cell grows in size and carries out normal metabolic activities [4].
2. S phase (Synthesis): In this phase, DNA replication and chromosome duplication occur [4].
3. G2 phase (Gap 2): The cell continues to grow and prepares for cell division [4].

Mitosis (M phase)

Mitosis is the actual phase of cell division and is divided into four stages:

1. Prophase: Chromosomes condense, the nuclear envelope and nucleolus disappear, and spindle fibers start to appear [4].
2. Metaphase: Chromosomes align at the equatorial plate [4].
3. Anaphase: Centromeres divide, and chromatids move towards

Basic Concepts

Characteristics of Living Things

• Movement - motion where the organism will go from one place to the other
• Responsiveness - how any organism reacts
• Growth - an organism's ability to get bigger
• Reproduction - ability of an organism to produce offspring
• Respiration - the ability of an organism to gain oxygen from food
• Digestion - ability of an organism to break down food
• Absorption - ability of an organism to take in nutrients
• Circulation - ability of materials to go through the body
• Assimilation - food is taken in and changed to something essential
• Excretion - ability of our bodies to remove waste

Homeostasis and Regulation

How does Fixism explain the diversity of living things?

(4 marks) Fixism claims that species were created the way they are now, given that they do not change. Therefore, the diversity we find today is the diversity that has always existed. c.

Explain why two very different species such as birds and butterflies can have similar wings, responsible for the same function. Which evidence of evolution is it? (4 marks)

Given that both species must adapt to the same environment, they end up developing similar structures. It is an example of convergent evolution.

According to Darwin, why do individuals compete against each other? What are the consequences of this constant competition? (4 marks)

The cause is the lack of resources in an environment and the... Continue reading "Explaining Diversity of Living Things: Fixism, Evolution, and Ecological Factors" »

Eyes

Orbital Hematoma (Black Eye)

An orbital hematoma, commonly known as a black eye, results from a blow to the area surrounding the eye, which causes capillary bleeding.

Signs & Symptoms:

• Noticeable swelling and discoloration around the orbit.

Orbital Fracture

An orbital fracture is caused by a direct blow to the eyeball, forcing it posteriorly. This action compresses the orbital fat until a blowout rupture occurs to the floor of the orbit.

Signs & Symptoms:

• Diplopia (double vision)
• Restricted eye movement
• Downward displacement of the eye

Hyphema

A hyphema is a collection of blood in the anterior chamber of the eye, typically resulting from blunt trauma to the eye. This is a major eye injury that can lead to serious problems.

Signs & Symptoms: