Stage 1 Biology - Topic 1 Multicellular Organisms

Flashcards from Stage 1 Biology - Topic 1 Multicellular Organisms lecture notes.

Cell specialisation

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

DNA

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

Protein

Large, complex molecules made up of amino acids that play many critical roles in the body.

Gene

What is a segment of DNA on a chromosome that codes for a specific trait?

Genome

all of an organism's genetic material

Amino acid

Building blocks of protein

Gene expression

process by which a gene produces a protein

Embryo

An organism in the earliest stage of development

Cell differentiation

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

Zygote

fertilized egg

Mitotic division

Cell division by means of mitosis.

Morphogenesis

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

Tissues

Groups of cells with a common structure and function.

Organs

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

Organ systems

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

Stem cell

unspecialised cell that can differentiate to become one or more types of specialised cells

Multicellular organisms

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

Epithelial tissue

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

Connective tissue

provides support for your body and connects all its parts

Nervous tissue

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

Muscle tissue

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

Nervous system

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

Circulatory system

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

Skeletal system

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

Digestive system

body system the breaks down food and absorbs nutrients

Excretory system

Removes liquid wastes (urea) from the body

Respiratory system

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

Endocrine system

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

Reproductive system

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

Ventilation

movement of air in and out of the lungs

Inhalation

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

Exhalation

the act of breathing out

Trachea (windpipe)

passageway for air to the bronchi

Bronchi

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

Bronchioles

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

Alveoli

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

Plasma

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

Red blood cells

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

White blood cells

cells involved in defense and immunity

Platelets

blood clotting

Arteries

carry blood away from the heart

Capillaries

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

Veins

Blood vessels that carry blood back to the heart

pulmonary circulation

heart to lungs to heart

systemic circulation

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

Autotroph

An organism that makes its own food

Heterotroph

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

Mechanical digestion

Physical breakdown of large pieces of food into smaller pieces

chemical digestion

Enzymes break down food into smaller molecules (monomers)

Mastication

the process of chewing

Peristalsis

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

Digestion in the mouth

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

Digestion in the stomach

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

Digestion in the smal l intestines

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 digeston

digestion in large intestine

Mechanical: Water and vitamins are absorbed

Kidneys

Filter blood from the renal arteries and produce urine as waste

ureter

A duct leading from the kidney to the urinary bladder.

bladder

stores urine

urethra

tube leading from the urinary bladder to the outside of the body

Nephron

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

Filtration in the nephron

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