science test

alveoli

small air baloons in your lungs, that are the primary site for gas exchange in the respatory and circulatory system.

amylase

an digestive enzyme that breaks down complex carbohydrates

anaphase

- centromeres split as spindle microtubules pull single chromosomes to opposite poles

Interphase

- dna replicates

- cell grows

- longest phase of the cell cycle ( 90% )

- cell performs life functions

- nuclear membrane appears

prophase

- chromosomes condense and become more visible

- centrioles move to opposite poles

- nuclear membrane disappears

- spindle fibres form at each pole from the centrioles

telophase

- single chromosome arrive at poles

- spindle fibres disappear

- centrioles replicate

- nuclear membrane reforms

- single chromosomes decondense, becoming chromatin again

aorta

The largest artery, located in your heart

cytokenesis

- the final physical stage of cell division

- cell membrane divides into daughter cells

when are the cell cycle checkpoints

- during mitosis

- during G1 of interphase ( before dna replication )

- during G2 of interphase ( just before mitosis )

why are theyŕe cell checkpoints

to check if...

- there is enough nutrients to support cell growth

- dna has been replicated

- dna has been damaged

what happens if problems are found during cell checkpoints

the cell cycle will stop and the cell is repaired or destroyed

apoptosis

programmed cell death that is essential for development. This happens to remove unnecessary, aged, or damaged cells without causing inflammation

cancer

a group of diseases led by uncontrolled growth and spread of abnormal cells

what are characteristics of a ¨normal¨ cell

- division of cells is controlled

- new cells are only formed for only growth and replacement of damaged cells

what are characteristics of an ¨abnormal" cells

- cancerous cells divide when they are not needed

- cancerous cells crowd out normal cells and function abnormally

- surrounding body tissues are destroyed

tumours

a mass of cells with no apparent function

generalists cells

- unicellular organisms, e.g., amoeba

- have many tasks, e.g., break down food, eliminate waste

specialists cells

- multicellular organisms e.g. skin, tissue, muscles

- have one or particular functions e.g. skin cells providing protection

tissues

groups of similar specialized tissues

dermal tissue

forms a barrier between plants and the external environment

ground tissue

performs photosynthesis and provides structual support

vascular tissue

xylem - transports water and dissolved minerals

phloem - transports sugars

what are the characteristics of xylem

- no end walls between cells

- outer cells are not living

- one - way only

- transports water and minerals

what are the characteristics of phloem

- end walls

- two - way movement

- cells are living, but need support

what are the four types of animal tissue

- epithelial

- connective

- nervous

- muscular

epithelial tissue

examples - skin, lining of digestive system

functions - protection, lining, exchange of minerals

connective tissue

can stretch, be a fluid and have mineral deposits

examples - blood, bones, fat, cartilage

functions - insulation, connects organs

nervous tissue

made of cells called neurons

examples - brain, nerves, spinal cord

functions - sensory, communication, coordination

muscle tissue

examples - cardiac muscle ( heart ), skeletal muscle ( biceps, hamstring ), smooth ( organs )

functions - movement

what are the characteristics of benign cells

- abnormal cells remain at the original sites

- can eventually become a malignant cell

what are the characteristics of malignant cells

- has the potential to spread to other parts of the body

- carried by blood and lymph system to other tissues

- able to start more tumours or metastastize

how does cancer develop

Cancer develops after a cell experiences a mutation in the DNA

( mutation can be triggered by...smoking, UV radiation, age, genetics )

what is the biological hierarchy of a cell

cell - tissue - organ - organ system - organism

organ

a combination of several types of tissue that work together to perform specific functions

organ system

a group of tissue and organs that work together to perform specific functions e.g. circulatory, disgetion, respiratory system

what are the functions of the digestive system

- converts foods into molecules that can later be used by the body

- get rid of waste

what is the path of food throughout the digestive system

1. mouth

2. esophagus

3. stomach

4. small intestine

5. large intestine

6. rectum and anus

mechanical digestion

your mouth and tongue breaking up food into smaller pieces

chemical digestion

- enzymes ( amylase ) breaks up food into smaller pieces

- amylase break down complex carbohydrates into simple sugars

bile

a digestive fluid produced by the liver, and stored in the gall bladder

red blood cells

- make up half of our blood by volume

- bright red and lack nuclei

function - contain hemoglobin protein that picks up oxygen and carbon dioxide

white blood cells

- make up 1% of our blood by volume

functions - destroy disease causing bacteria and viruses

platelet

- small cells that make up less than 1% of our blood

functions - help blood clot, seal wounds, and stop bleeding

plasma

protein rich liquid in which blood cells float

functions - carries blood cells dissolved, waste, nutrients, and hormones

bronchi

the two branches of the trachea, each connect to a lung

capillaries

small and delicate blood vessels in which gas exchange takes place between blood and the bodies cells and tissues

centrioles

microtuble based organelles found in animal cells, usually located in the nucleus

centromere

the region of a eukaryotic chromosome that connects sister chromatids

chemotherapy

drugs that are used to stop dna replication, mitosis, and blood vessel growth

chromatid

one of the two identical halves of a chromosome when joined at the centromere

chromatin

a complex of DNA and protein

functions - condensing long DNA molecules into compact structures within bacterial and eukaryotic cells

chromosomes

a package of dna that contains part or all of the genetic material of an organism

functions - they carry an organisms blueprint and ensure that DNA and properly copied and distributed during cell division

diaphragm

a dome shaped sheet of muscle below the lungs

- contracts and moves down during inhalation

- relaxes and moves up during exhalation

DNA

the molecule that carries genetic instructions for the development, function, growth, and reproduction of organisms

enzyme

usually proteins that contain amino acids e.g. aspartate

functions - speed up chemical reaction in living things without being consumed

epiglottis

a small cartilage flap located in the throat, behind the tongue

function - acts as a valve that covers the trachea during swallowing in order to prevent liquid from entering the lungs

esophagus

a muscular tube in the digestive tract that connects the pharynx to the stomach

functions - pushes food ( bolus ) to stomach using a muscular wave ( peristalsis )

gall bladder

a pear shaped organ located in the upper abdomen, beneath the liver

functions - stores bile produced by the liver to aid in digesting fats

genes

the basic, functional units composed of DNA sequences that instruct cells to produce or regulate

hemoglobin

a protein that picks up oxygen and carbon dioxide

intercostal muscles

the three layers of muscles that are situated in the ribs

- external

- internal

- innermost

large intestine

the last step of the digestive tract

functions - absorbs water, digests beneficial bacteria that we absorb as vitamins, forms feces with indigestible parts of chyme

chyme

fluid mass of partly digested food, water, and digestive enzymes e.g. hydrochloric acid, and bile

liver

the organ located in the upper abdomen

main functions - blood detoxification, stores bile, breaks down toxins e.g. alcohol

lungs

primary organ involved in the respatory system

functions - exchange of oxygen and carbon dioxide

what is the function of microvilli

increasing surface area for nutrient uptake, fluid transport, and absorption in the kidneys and digestive tract

mitosis

a process of cell division in which a eukaryotic cell replicates its chromosomes and divides them into identical daughter cells

nuclear membrane

a double layer that encloses the cells nucleus

functions - protects dna, seperates nucleus from cytoplasm

peristalsis

the wave like contraction and relaxation of muscles in the digestive tract that moves food through the body

pancreas

a large gland that is known for its production of enzyms that help chemically digest fodo

salivary glands

produce saliva which initiates digestion

small intestine

the part of the digestive system that performs majority of the food digestion and nutrient absorption

functions - breaks down food into small molecules

- absorbs vitamins, minerals, fats, carbohydrates, proteins and water

small intestine ridges

deep permanent ridges in the small intestine

function - spiral chyme to slow its movement and maximize nutrient absorption

spindle microtubles

structures from dynamic microtubles

function - separate chromosomes to newly formed daughter cells

systemic circuit

a part of your cardiovascular system that transports oxygenated blood from the left ventricle to the aorta, arteries, and blood tissues

trachea

a tube that connects the larynx to the bronchi which allows air to pass through the lungs

veins

blood vessels in the circulatory system

functions - return deoxygenated blood to the heart and lungs to be re - oxygenated

pharyx

the common passageway for food and air

what are the functions of nasal and oral cavities

- nasal cavity is lined with hairs, cillia, and mucus that trap and filter dust and airborne particles

- prevents damage to delicate internal respiratory membranes

prokaryotes

single celled organisms that include bacteria, and lack a nucleus and membrane bound organelles

cell membrane

a barrier surrounding all living cells, separating the cytoplasm from the extracellular environment

cytoplasm

the water based substance that fills cells, enclosed by the cell membrane and containing cytosol and organelles

mitochondria

membrane bound organelles located in the cytoplasm of almost all eukaryotic cells

functions - generates over 90% of the cells chemical energy ( stored as ATP )

chloroplast

specialized organelles found in plants that conduct photosynthesis which converts solar energy into chemical energy to fuel the organism

vacuole

a membrane bound organelle found in plant and animal cells

function - stores water, nutrients, and waste

lysosome

membrane bound organelles that acts as a cells garbage disposal and recyling center

centrosome

a non membrane bound organelle in animal cells

functions - the main mictrotubles organization centre, regulates the cell cycles progression

genome

the complete set of genetic instructions, found in an organism containing all the information it needs to develop, function and reproduce

metastastize

the process in which cancer cells break away from the primary tumour, travel through the bloodstream or lymphatic system, and form new secondary tumours

mutagen

a physical or chemcial agent that permanently changes genetic material in an organism e.g. uv radiation, x - rays

deoxygenated blood

oxygen poor

carbon dioxide rich

oxygenated blood

oxygen rich

carbon dioxide poor

arteriosclerosis

the thickening of the walls of arteries, which narrows blood passageways

how are strokes caused

occurs when a blood clot reaches the brain and blocks a vessel

hypertension

high blood pressure ( one of the main causes of heart disease )

pepsin

a primary digestive enzyme

function - breaks down food proteins into smaller amino acids

pneumonia

- inflammation of the air sacs in the lungs ( alveoli ).

- inflammation can be caused by infection but also by inhalation of foreign particles

- alveoli fill up with fluid and dead white blood cells, making it hard to breathe

- symptoms include fever, chills, coughing, and chest pain

- can be treated by antibiotics

asthma

- a respiratory disorder caused by the inflammation and narrowing of the bronchial tubes

- an asthma attack can be triggered by bacteria, viruses, and certain foods

- the mucus membrane lining the tubes swells up and produces excess mucus which causes coughs and difficulty breathing

what are the 3 reasons for cell division

growth, asexual reproduction, and repair, replacement

kidneys

the bodies primary filteration system

functions - filter blood to remove toxins, regulate water levels and balance minerals