Stage 1 Biology - Topic 1 Multicellular Organisms

Flashcards from Multicellular Organisms Lecture Notes

What is cell specialization?

When particular genes within a cell are switched on/off so that a cell can perform specific functions.

What is DNA?

A complex molecule containing the genetic information that makes up the chromosomes.

What are proteins?

Large, complex molecules made up of amino acids that play many critical roles in the body. They do most of the work in cells and are required for the structure, function, and regulation of the body's tissues and organs.

What is a gene?

A segment of DNA on a chromosome that codes for a specific trait.

What is a genome?

All of an organism's genetic material.

What is an amino acid?

Building block of protein

What is gene expression?

The process by which a gene produces a protein.

What is an embryo?

An organism in the earliest stage of development.

What is cell differentiation?

The process by which a cell becomes specialized for a specific structure or function.

What is a zygote?

Fertilized egg

What is mitotic division?

Cell division by means of mitosis

What is morphogenesis?

The process by which an organism takes shape and the differentiated cells occupy their appropriate locations.

What are tissues?

Groups of cells with a common structure and function.

What are organs?

Groups of tissues that work together to perform a specific function or related functions.

What are organ systems?

A group of organs that work together in performing vital body functions.

What is a stem cell?

Unspecialized cell that can differentiate to become one or more types of specialized cells.

What are multicellular organisms?

Organisms composed of many cells (Ex. tissue, humans, etc.)

What is epithelial tissue?

Tissue that covers the outside of the body and lines organs and cavities.

What is connective tissue?

Provides support for your body and connects all its parts.

What is nervous tissue?

A body tissue that carries electrical messages back and forth between the brain and every other part of the body.

What is muscle tissue?

A body tissue that contracts or shortens, making body parts move.

What is the nervous system?

The network of nerve cells and fibers that transmits nerve impulses between parts of the body.

What is the circulatory system?

Transports oxygen, waste, nutrients, hormones, heat, etc… around the body.

What is the skeletal system?

Protects and supports body organs and provides a framework the muscles use to support movement. Made up of bones and joints.

What is the digestive system?

Body system that breaks down food and absorbs nutrients

What is the excretory system?

Removes liquid wastes (urea) from the body

What is the respiratory system?

Gas exchange - Brings oxygen into the body. Gets rid of carbon dioxide.

What is the endocrine system?

Consists of glands that control many of the body's activities by producing hormones.

What is the reproductive system?

Reproduce offspring - produce male sex cells (sperm) and female sex cells (oocytes)

What is ventilation?

Movement of air in and out of the lungs.

What is inhalation?

The act of taking in air as the diaphragm contracts and pulls downward.

What is exhalation?

The act of breathing out.

What is the trachea?

Passageway for air to the bronchi (windpipe)

What are the bronchi?

Two short branches located at the lower end of the trachea that carry air into the lungs.

What are bronchioles?

Airways in the lungs that lead from the bronchi to the alveoli.

What are alveoli?

Tiny sacs of lung tissue specialized for the movement of gases between air and blood.

What is plasma?

Liquid part of blood - transport products of digestion, minerals, vitamins, carbon dioxide, urea and heat.

What are red blood cells?

Blood cells that carry oxygen from the lungs to the body cells.

What are white blood cells?

Cells involved in defense and immunity.

What are platelets?

Blood clotting

What are arteries?

Carry blood away from the heart.

What are capillaries?

Thin blood vessels through which exchanges take place between the blood and cells of the body.

What are veins?

Blood vessels that carry blood back to the heart.

What is pulmonary circulation?

Heart to lungs to heart

What is systemic circulation?

Circulation that supplies blood to all the body except to the lungs

What is an autotroph?

An organism that makes its own food

What is a heterotroph?

Organism that obtains energy from the foods it consumes; also called a consumer

What is mechanical digestion?

Physical breakdown of large pieces of food into smaller pieces.

What is chemical digestion?

Enzymes break down food into smaller molecules (monomers).

What is mastication?

The process of chewing.

What is peristalsis?

Involuntary waves of muscle contraction that keep food moving along in one direction through the digestive system.

What occurs during digestion in the mouth?

Mechanical: Teeth grind food. Tongue mixes food. Chemical: Saliva moistens food. Breaks down starches

What occurs during digestion in the stomach?

Mechanical: Churning. Chyme is formed. Chemical: Hydrochloric acid breaks down food and kills bacteria. Pepsin breaks down protein

What occurs during digestion in the small intestine?

Large SA from villi and microvilli that allow nutrient absorption. Pancreatic juices neutralise stomach acid. Bile (produced in liver) from gall bladder enters and emulsifies fats for digestion

What occurs during digestion in the large intestine?

Mechanical: Water and vitamins are absorbed

What is the function of the kidneys?

Filter blood from the renal arteries and produce urine as waste

What is the ureter?

A duct leading from the kidney to the urinary bladder.

What is the function of the bladder?

Stores urine

What is the urethra?

Tube leading from the urinary bladder to the outside of the body.

What is a nephron?

Functional unit of the kidney consisting of Bowman's capsule, glomerulus and tubule

What occurs during filtration in the nephron?

Removal of water, salt, urea, and glucose from the blood. RBCs and large proteins do not pass through to filtrate.

What occurs during reabsorption in the nephron?

Flow of water, ions, glucose, amino acids from filtrate to blood

What is the central nervous system?

Brain and spinal cord

What is the peripheral nervous system?

The sensory and motor neurons that connect the CNS to the rest of the body.

What is the function of the brain?

Controls nervous and hormonal systems. Made up of cerebrum, cerebellum and brain stem

What is the function of nerve cells (neurons)?

Involved in the generation and interpretation of electrical signals

What is a stimulus?

A change in environment that causes an organism to react

What are sensory receptors?

Sensory nerve endings that respond to stimuli

What is the stimulus-response model?

stimulus, receptor, sensory neuron, interneuron, motor neuron, effector, response

What is the function of sensory neurons?

Carry impulses from the sense organs to the spinal cord and brain

What is the function of inter-neurons?

Located in the brain and spinal cord - connect sensory and motor neurons.

What is the function of motor neurons?

Neurons that carry signals from the spinal cord to the muscles to produce movement

What is a reflex response?

Involuntary reaction to a stimulus that does not pass through the brain. stimulus, receptor, interneuron (spinal cord only), motor neuron, effector and response

What are the organs of the endocrine system?

pituitary, thymus, thyroid, parathyroid, adrenal, and pineal glands; ovaries, testes, and pancreas

What is a hormone?

A chemical released from cells of an endocrine gland that travels in the blood and binds to a specific receptor on a target cell

What is the pituitary gland?

The endocrine system's most influential gland; regulates growth and controls other endocrine glands

What is homeostasis?

The maintenance of a relatively constant conditions within an organism despite external changes - "a steady state"

What is a negative feedback loop?

A response that occurs to reduce a stimulus and thereby maintain homeostasis.

What is thermoregulation?

Process of maintaining an internal temperature within a tolerable range.

What is piloerection?

Condition of the hair standing straight up - Goose-bumps

What is vasoconstriction?

Constriction of a blood vessel

What is vasodilation?

Dilation of a blood vessel

What is a positive feedback loop?

A feedback loop in which change in a system is amplified

What are cartilage?

Connective tissue

What is striated muscle tissue?

Connective tissue