BIOLOGY TEST

cell theory

1. All living organisms are composed of one or more cells.

2. The cell is the basic unit of structure and organization in organisms.

3. Cells arise from pre-existing cells.

Animal cell organelles

nucleus, endoplasmic reticulum, cytoplasm, vacuole, golgi body, cell membrane, vesicle, cytoskeleton, mitochondrion, ribosome

cell membrane

separates the inside of the cell from the external enviroment; controls the flow of materials into and out of the cell, semi-permeable membrane

Cytoplasm

includes the cytosol, the organelles, and other life-supporting materials, such as sugar and water, all contained by the cell membrane, mostly water

Mitochondria

(singular: mitochondrion) where energy is released from glucose to fuel activities through process called cellular respiration

Ribosomes

help to produce proteins, which make up much of a cell's structure and are required for activities necessary for the cell's survival; some ribosomes float in the cytoplasm, and others are attached to the endoplasmic reticulum

Endoplasmic Reticulum

a network of membrane-covered channels that transport materials made in the cell; is connected to the nucleus, three-dimensional network of branching tubes and pockets, extends throughout cytoplasm from the nuclear membrane, fluid-filled tubes transport materials i.e proteins, thru cell

vesicles

membrane-covered sacs that transport and/or store materials inside the cell and sometimes help these materials cross the cell membrane to enter or exit the cell

Golgi body

sorts and packages proteins and other molecules for transport out of the cell, make and secrete mucus (cells secrete a lot, i.e intestine cell have many of golgi)

Nucleus

Control center of the cell, has chromosomes that contain your DNA, separated by rest of cell by nuclear membrane

Vacuoles in animal cell

contain water and other materials and are used to store or transport small molecules; plant cells tend to have one large vacuole; animal cells may have several smaller vacuoles.

How many cells are humans made of

100 trillion cells

celullar metabolism

Set of chemical reactions occur in living organisms to mantain life, processes carried out by the individual cells that make up the organism

what essential tasks do all cells have to do for cellular metabolism

obtain food and energy, convert energy for use inside the cell

construct + mantain cell structures

carry out chemical reactions

eliminate wastes

reproduce, keep blueprints for constructing cell structures (chromosomes)

Unicellular

A single celled organism

Multicellular

Made up of more than one cell.

what two groups are all living things categorized into based on features of cells

prokaryotes and eukaryotes

vacuole in plant cell

usually have one large vacuole take up all space, when full of water, tugor pressure keeps cells plump which keep plant stem + leaves firm

Organelle

specialized cell structure that has a specific function, usually enclosed within its own membrane

Prokaryotes

cells w/ very simple cell structure, do NOT have nucleus or membrane-bound organelles, free floating, unicellular, most have cell wall, smaller than eukaryotic, rhymes with NO, no mitochondria, no ER, no Golgi Apparatus

Eukaryotes

rhymes with DO, more complex internal organization, contain nucleus and membrane-bound organelles like mitochondria, ER, golgi apparatus, can form both unicellular and multicellular, larger than prokaryotes

example of prokaryote

Bacteria and Archaea (single-celled life forms)

Examples of eukaryotic cells

Amoeba (single-celled), whales and trees (multi-cellular)

Relationship between prokaryotes and eukaryotes chart

chloroplast

found only in plant cells; trap energy from the Sun to make glucose, which is broken down in the mitochondria to power cell activities (animals must get glucose from the food they eat), contain chlorophyll (give leaf green color)

name two diff. in plant and animal cells

cell wall and chloroplasts

purpose of cell division

allows organisms to reproduce, allow organisms to grow, allows organisms to repair damage

what are the two types of reproduction

asexual reproduction and sexual reproduction

asexual reproduction

one parent, genetically identical to parents

sexual reproduction

offspring gets genetic info from 2 parents, each parent contribute one gamete which fuses with other

gamete

come from normal body cell, contain half of DNA found in cell, to make, some parent cell go thru meiosis,

why do the size of cells not increase

bc too large chemicals, water and waste cannot be transported quickly enough

how to chemicals in a cell move by

diffusion

diffusion

a transport mechanism for moving chemicals into and out of the cell, from an area of higher concentration to an area of lower concentration

concentration

the amount of a substance (solute) present in a given volume of solution

osmosis

the movement of a fluid, usually water, across a membrane toward an area of high solute concentration

how much cell division for skin cells

every day, millions of cells must be replaced

how much cell divide in red blood cells

each cell is replaced every 120 days

How cell divide when broken bones, cuts and blister

new cells needed to fill in gaps

DNA, and structure of DNA

Holds genetic code for your body to develop, survive and produce. Chromatin is a thread-like material inside the nucleus, material contains genetic info called DNA (deoxyribonucleic acid) a substance that chromosomes are composed of that make up the genetic code

lysosomes

membrane bound organelles who have digestive enzymes to process energy

photosynthesis equation

carbon dioxide + water —> glucose, oxygen and energy

cellular respiration equation

glucose + oxygen —> water and carbon dioxide

what are the stages of the cell cycle

interphase, mitosis (cell division of nucleus) cytokinesis (cytoplasm division)

how long does embryonic cells take to divide

long time

how long does it take for adult nerve cells to divide

may never divide

Interphase

Longest stage of cell cycle, perform normal functions and prepare for cell division by duplicating genetic material (DNA) strands, first stage, also doubles centrosomes

order of mitosis

PMAT, prophase, metaphase, anaphase telophase

what happens when something goes wrong in interphase

copying errors are detected and fixed by special proofreading and repair proteins

prophase

replicated chromosomes coil in various ways until they are condensed and thick enough to be visible under microscope. membrane around nucleus breaks down and nucleolus disappears. each chromosome are joined together by centromere. chromosome contain two strands called sister chromatids. the two centrosomes (part of cytoskeleton) begin to form spindle fibers and go to opposite ends. As prophase progress, spindle fibres extend away from centrosomes to each centromere on chromosome

metaphase

Longest phase in mitosis, centrosomes reach end of cell, chromosomes move to line up in centre of cell. spindle fibres stretched to centromeres. each centromere becomes attached to two spindle fibres-one from each end of cell

anaphase

one of shortest stage, centromere holding two chromatids together break apart as the spindle fibres stretch to chromosomes pull back said chromatid, then chromatid become daughter chromosomes as their own, this point cell has twice as many chromosomes

telophase

spindle fibres disappear, and membrane form around new daughter chromosomes and in the membrane, a nucleolus appears, chromosomes uncoil become harder to see. Mitosis, the division of one nucleus into two identical nuclei is now complete, rest of cell is ready to divide

cytokinesis

final stage of cell division, division of everything else except nuclei, specifically of the cytoplasm though

cytokinesis in animal cells

start in anaphase end in telophase, where ring of specialized proteins around middle of cell start to contract, pinches cell membrane until divided into two daughter cells

cytokinesis in plant cell

cell wall makes cytokinesis different. golgi body make new vesicles (tiny vacuoles) which carry material needed to make a new cell wall. The vesicles line up between two nuclei in a line forming a cell plate. cell plate grows outwards and joins cell wall which makes new cell walls on each side

two types of ways cells get destroyed

cell death and cell suicide

cell death

contents leaks out, often irritating surrounding cells, causing swelling and redness in that body part.

cell suicide

breaks down in organized way, contents packaged + distributed for other cells usage, this is pre-programmed into cells, determind by suicide genes

cancer cell

continues to divide ignoring stop signs in the cell cycle, so instead of dying, they divide repeatedly and excessively, forming a tumor

where does cancer occur usually give examples

in cells that are rapidly dividing like skin, lung, breath, and cells lining intestinal tract

benign tumor

a tumour that does not affect surrounding tissues other than by physically crowding them. not cancerous but can affect function of other tissues when crowding

malignant tumor

a tumour that interferes with the functioning of surrounding cells; a cancerous tumour. interferes with function of cell like ability to produce hormones or enzymes, and can destroy cells

metasis

the process of cancer cells breaking away from the original (primary) tumour and establishing another (secondary) tumour elsewhere in the body

metastatic (cancerous) cells

leave the tumour and start a secondary tumour elsewhere

causes of cancer

mutation, or mutagens and carcinogens

How does mutation happen

normal cell do 20-30 rounds, any more make mutation. most suicide but many cancer cell mutation been found make enzyme called telomerase which signals don’t stop dividing. also mutate so dont have to divide on surface like normal cell. take at least 4 mutations

mutation

a change in the DNA sequence of an organisms

Mutagen

substance of agent that induces heritable change in cells or organisms

carcinogen

any environmental factor that causes cancer

what are some well-known carcinogens

x-rays, UV radiation, smoking, organic solvents, viruses (human papilloma virus HPV)

steps of a secondary tumor formation

step one: primary tumor develops as a group of cells that are growing out of control

step two: the tumor gets bigger and stimulates blood vessels to supply it from the surrounding tissues

step three: tumor cells squeeze into blood and lymph vessels and move to other parts of the body, this is called metasis

step four: as tumor cells reach other parts of body, form secondary tumors.

cancer screening

tests detect cancer even if there are no symptoms so detect at early stage so it can be treated more effectively

PAP test

named after Dr. George Papanicolaou, who invented it, it is done routinely as physical checkup, remove small sample of cells from woman’s cervix then examined for abnormalities. for adult women, around 18 and higher, check for cervical cancer.

genetic screening

important for people who have family history of cancer, determine if you inherited DNA linked to cancer

different types of cancer screening

PAP test, testicular self-examination, PSA test, breast self examination, mole observation, blood test for colon cancer

PSA test

blood test, screen for prostate cancer and NOT wildly used for men under 50 bc chances for them are low

mole observation, skin checks

check own skin using ABCD, Asymmetry, Border, Color, and Diameter

how to reduce risk of cancer

no smoking, healthy diet, exercise

ways to diagnose cancer

imaging tech like endoscopy, x-rays, ultrasounds, CT scanning, and MRI, OR taking a sample of cells under a microscope,

endoscopy, endoscope

used to screen for colon cancer, a tiny camera + fibre-optic light attached to flexible tube find diagnosis. Can have forceps attached to get small sample. ex. Can see stomach ulcer (hole in protective mucous lining of stomach/intestine)

x-ray, specialized example, and damaging effects

produced by transmitting wavelength of electromagnetic radiation through body to expose photographic film on other side (ex. mammogram specialized x-ray technique imaging breast tissue).but can also cause DNA damage, and harmful to rapidly dividing cells (i.e growing fetus).

Ultrasound imaging

Directing high-frequency sound waves at part of body from a microphone attached to computer, create digital image, real-time movement of body parts so good for watching organ function

CT/ CAT scan

computerized axial tomography, take multiple x-rays of thin ‘slices’ of a body part, then images assembled by computer make 3D images.

MRI

magnetic resonance imaging, produced using radio signals in magnetic field create images more detail than CT scan, then computer make three-dimensional models

biopsy

sample of tumor cells removed surgically, tested

Treatments for cancer

chemotherapy, surgery, radiation therapy, biophotonics

chemotherapy

treat cancer using drugs, slows/stops cancer cells from stopping. can be taken orally and side effects include hair loss, nausea, fatigue bc chemo attack all rapidly dividing cells. often first stages to shrink tumor for surgical removal or radiation treatments. Can detect small tumours

radiation

energy from gamma rays or x-rays, cancer cells easily damaged by ionizing radiation bc they divide quickly. DNA of daughter cells damaged by the radiation, so cells cannot divide. can be directed at tumor using focus beam or implanting radioactive source into tumour

biophotonics

use light beams detect + treat cancer. sensitive allowing early detection, fewer side effects and more accurate. pioneered at UOFT

what cells divide quickly and why

skin cells, blood cell, hair cells, stomach cells because they are constantly getting harmed and if they don’t divide that will harm the body and give it less layers of protection

Levels of organization in organisms

cell, tissue, organ, organ system, organism

four major types of tissues

epithelial tissue, connective tissue, muscle tissue, and nerve tissue

epithelial tissue, where found, function, and descript.

skin, lining of digestive system, protect from dehydration, low-friction surfaces, thin sheets of tightly packed cells covering organs lining internal organs

connective tissue, found where, descript, function

Makes up bones and tendons, support, insulate, connects cells + tissues, cells in extracellular matrix range from liquid (in blood) to elastic materials can stretch (ligaments) to mineral deposits (bone)

types of epithelial tissue

skin epithelia (thin flat cells form sheets, the skin) and columnar epithelia (lining small intestine, stomach + glans, may secree mucus, cilia and absorb materials

muscle tissue found where, function, descript.

Muscle make bones move, surrounding digestive tract, the heart, for movement, designed to change shape by shortening/lengthening

How many types of cells is the body made up of where do they come from

200 different types, come from pool of stem cells from early embryo

cellular differentiation

the process by which a cell becomes specialized to perform a specific function

Stem cell

an undifferentiated cell that can divide to form specialized cells