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

Levels of Biological Organization

• Atom: The smallest component of chemical elements that make up living things (bioelements), primarily Carbon (C), Oxygen (O), Hydrogen (H), Nitrogen (N), Phosphorus (P), Sulfur (S), Calcium (Ca), Magnesium (Mg), and Sodium (Na).
• Molecule: A group of two or more atoms joined together chemically.
• Organelles: A group of biomolecules that work together to form cell structures, such as membranes, ribosomes, and mitochondria.
• Cell: A group of organelles and structures. A cell is the simplest level of life.
• Tissue: A group of specialized cells that work together to perform a specific function.
• Organ: A group of different tissues that work together to carry out a specific function.
• Organ System: A group of similar or different

1) Singer and Nicolson's fluid mosaic model of the membrane proposed that membranes consist of protein molecules embedded in a fluid bilayer of phospholipids

2) Which component is a peripheral protein?

D

3) Which component is cholesterol?

D

4) Which component is a protein fiber of the extracellular matrix?

A

5) Which component is a microfilament (actin filament) of the cytoskeleton?

C

6) Which component is a glycolipid?

B

7) Which of the following most accurately describes selective permeability?

Only certain molecules can cross a cell membrane.

8) Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly?

CO2

9) Which of the following allows water to move much faster across cell membranes?

aquaporins

10) Diffusion... Continue reading "Understanding Cell Membrane Components and Functions" »

What is Cytology?

Cytology is the study of the internal structure and function of individual cells.

What is Histology?

Histology is the study of the microscopic structure of tissues.

What is Anatomy?

Anatomy is the study of the structure and relationship between body parts. There are several sub-disciplines within anatomy:

Surface Anatomy

Surface anatomy is the study of the external features of the body.

Regional Anatomy

Regional anatomy is the study of anatomy based on regions of the body. It involves the study of the superficial and internal features in a specific area of the body.

Pathological Anatomy

Pathological anatomy is the medical specialty concerned with the diagnosis of disease based on the gross and microscopic examination of tissues.

What

Fundamentals of Ecology

Ecology is the scientific discipline in which the relationships among living organisms and the interactions they have with their environments are studied.

Key Concepts

The biosphere consists of all life on Earth and all parts of the Earth in which life exists, including land, water, and the atmosphere. A habitat is an area where an organism lives.

Ecosystem Components

Abiotic factors are nonliving factors in an organism’s environment, while biotic factors are living factors in an organism’s environment.

Levels of Ecological Organization

Ecological studies focus on several levels:

• Organism
• Population
• Community
• Ecosystem
• Biome
• Biosphere

Energy Flow in Ecosystems

Producers and Consumers

Autotrophs (producers) make their own food, while... Continue reading "Ecology Essentials: Interactions, Energy Flow & Cycles" »

Understanding Key Biological Systems and Health Concepts

Intestines

The intestines are a long, continuous tube running from the stomach to the anus. Most absorption of nutrients and water happens in the intestines. The intestines include the small intestine, large intestine, and rectum.

Excretory System

The excretory system is a passive biological system that removes excess, unnecessary materials from the body fluids of an organism.

Liver

The liver's main job is to filter the blood coming from the digestive tract before passing it to the rest of the body. The liver also detoxifies chemicals and metabolizes drugs.

Double Circulation

Double circulation describes the process where blood is first pumped into the lungs, where it becomes oxygenated, and... Continue reading "Key Biological Systems and Health Concepts Explained" »

Digestive System Diseases

Oral Cavity

• Tooth Decay

  Tooth enamel is destroyed by acids produced by bacteria that break down food fragments stuck between teeth. Tooth decay causes cavities to form, and bacteria in the cavities can then destroy the teeth.

• Gingivitis

  Inflammation of the gums caused by vitamin deficiencies or poor dental hygiene.

Stomach

• Gastroenteritis

  An infection affecting the stomach or intestine, caused by bacterial toxins. Symptoms include diarrhea, vomiting, abdominal pain, and fever.

• Gastritis

  Irritation of the gastric mucosa causing pain, acidity, and a burning sensation. Often caused by smoking, drinking alcohol, eating spicy foods, or taking medicine.

• Stomach Ulcer

  Damage to the gastric mucosa which causes the stomach cavity to come

Unit 3: Lessons 1

Bioelements

Atoms are linked together to form elements. A chemical element is formed by similar atoms.

Biomolecules

Atoms are linked together to make molecules. There are two types of molecules: inorganic and organic.

Cell

This is the smallest unit of living matter that can exist freely in a medium, as it can carry out all the functions of living beings.

Multicellular Levels

• Tissue: A group of cells similar in structure that work together to perform a specific function.
• Organ: Several tissues grouped together to make a structure with a specific function.
• Organ System: A group of organs with closely related functions.
• Organism: The complete unit of the living being.

Unit 3: Lesson 2

Enzymes

Most chemical reactions in living beings would... Continue reading "Essential Building Blocks of Life: From Atoms to Organisms" »

The Pulmonary Circuit

The pulmonary circuit begins in the right ventricle where deoxygenated blood is pumped through the pulmonary artery to each lung. The artery branches, finally becoming a network of capillaries that carry deoxygenated blood to the alveoli where gas exchange occurs. After gas exchange, oxygenated blood travels through the venous capillaries, the venules, and finally the pulmonary veins to the left atrium.

The Systemic Circuit

The systemic circuit begins in the left ventricle. Oxygenated blood is pumped through the aorta to the upper and lower body. It travels through the arteries, arterioles, and finally arterial capillaries to reach the cells. There, during cellular metabolism, nutrients and oxygen are collected while carbon... Continue reading "The Pulmonary and Systemic Circuits: Functions and Diseases" »

Anatomical Changes in Human Evolution

Anatomy is the scientific study of the structures of living things, including their systems, organs, and tissues.

Bipedalism: The Upright Stance

Bipedalism first appears with Australopithecus. Due to a climate change, the jungle turned into grassland, necessitating walking upright to see over the grass. This process required many transformations:

• The legs became longer.
• The arms became shorter.
• The hands were freed.
• The pelvis became narrower.

Encephalization: Brain Enlargement

Encephalization is the progressive enlargement and increasing complexity of the hominid brain. This change is due to the expansion of the cranial cavity.

Changes in Hand Structure

The palm became shorter and the fingers became longer. Hominids... Continue reading "Key Evolutionary Changes: Anatomy, Physiology, and Social Development" »

1. In DNA structure, A always pairs with T. TRUE
2. In DNA structure, cytosine always pairs with adenine. FALSE
3. How many stop codons are there in the genetic code? 3
4. In the genetic code, how many start codons are there? 1
5. In the genetic code, how many naturally occurring amino acids are there? 20
6. Dominant genes are about three times more common than recessive genes. FALSE
7. In this class, Peigler's policy on handheld devices is that they should be turned off and kept out of easy reach. TRUE
8. The traits we studied in the ear of corn were: seed color and plumpness
9. If you cross a white mouse and a black mouse and get gray mice, this is an example of: incomplete dominance
10. Which of the following genotypes is called homozygous dominant? BB
11. Gregor Mendel was a monk