biology y9 topic 1 (cell biology)

put these in order of size: Organ, Tissue, Organelle, atom, organism, cell, molecule, organ system

atom, molecule, organelle, cell, tissue, organ, organ system, organism

what is an organelle?

small sub-cellular structures

what is a cell?

basic unit of life

what is a tissue?

A group of cells that work together to perform a specific function

what is an organ?

groups of tissues that work together to perform a specific function

what is an organ system?

Organs and tissues that work together to perform a specific function

What is an organism?

Organ systems that work together to enable life

name MRSHGREN

Movement Reproduction Sensitivity Homeostasis Growth Respiration Excretion Nutrition

What is Homeostasis?

Keeping the body system stable and balanced

Name 6 organ systems

Skeletal, Nervous, Circulatory ,Gas exchange ,Digestive, Muscular

Circulatory system function?

to transport nutrients and oxygen round the body

Reproductive system function?

to reproduce the next generation

Excretory system function?

to get rid of metabolic waste mase by the body

Gas exchange function?

To obtain oxygen and get rid of co2

Digestive system function?

To convert large insoluble molecules into small soluble ones

Skeletal/muscular system function?

To support the body and allow movement

nervous system function?

To respond very quickly to change in the surroundings and control vital body processes

immune system function?

To protect the body from microbes and disease

hormonal system function?

To respond to internal changes and control vital body processes. transports chemical signals through blood

is anything smaller than a cell alive?

nope

what are cells made up of?

Organelles (however they cannot survive alone)

What organelles are part of a plant cell?

Nucleus, Mitochondria, cytoplasm, vacuole, cell wall, cell membrane, ribosomes, chloroplasts

Nucleus function?

contains DNA

mitochondria function?

carries out respiration

Cytoplasm function?

chemical reactions take place here

Cell membrane function?

controls what enters/exits the cell

Ribosome function?

where proteins are made

cell wall function?

made of cellulose which gives support/strength to the cell

vacuole function?

storage area which contains cell sap. water pressure in here helps to support the cell

chloroplasts function?

makes food (by photosynthesis) using green chlorophyll

Organelles in an animal cell?

Nucleus, cytoplasm, cell membrane, mitochondria

What is an Eukaryote?

something that has a nucleus

What is a unicellular organism?

organisms that are made of just one cell

Features of a prokaryote?

Have no nucleus (DNA in cytoplasm), Have ribosomes+ cell membrane+ cell wall, Have no mitochondria or vacuole, carries out binary fission

What is Binary Fission?

the process through which asexual reproduction happens in bacteria

feature of an eukaryote?

have a true nucleus, have all the usual structures+ organelles, carries out mitosis

What does a microscope do?

produces a magnified image of an object that are too small to be seen via the naked eye

total magnification equation?

mag of eyepiece x mag of objective lens

what is the eyepiece lens mag?

x10

low/med/high power objective lens mag?

x4, x10, x40

what are the different types of microscopes?

light microscope, scanning electron microscope, transmission electron microscope

features of a light microscope?

max mag = x2000, 2d shape, resolving power = 200nm, object could be alive

features of a scanning electron microscope?

max mag = x500,000, resolving power = 10nm, 3d image, object has to be dead

feature of a transmission electron microscope?

max mag = x1,000,000, resolving power = 0.2 nm, 2d image

microscope magnification definition?

how many times larger an image is compared to real life

resolution definition?

the ability to distinguish between two separate points. the amount of detail that can be seen.

what is the SI (standard) unit for measuring length?

metres

magnification equation for actual size?

I(mage) = A(ctual size) x M(agnification)

specialized cell definition?

cells that have a special adaptation to help them carry out a specific function

what is differentiation?

when cells become specialized they can can change shape and gain/lose specific organelles

differentiation definition?

the production of specialized cells in plants+animals to enable them to carry out specific functions

differentiation in animal cell…

tends to happen at an early stage

differentiation in plants…

happens throughout their life

characteristics of stem cells?

they are unspecialized, they are undifferentiated, replicate themselves for long periods of time to form clones, can differentiate into lots of different types of cells

what are clones?

genetically identical cells

stem cell deffinition?

simple cell which is able to divide and produce many more of the same type. can also produce many differentiated specialized cells.

what are the two types of stem cell found in mammals and humans?

embryonic stem cells and adult stem cells

what are embryonic stem cells?

can differentiate and become any of the specialized cells, tissues and organ of an embryo. can produce a complete organism

what is an adult stem cell?

cells found in adult tissues. they act as a repair system for the body, they replace cells that are lost through normal wear/tear, injury or disease.

how can you get embryonic stem cells?

taken from human embryos

how can you get adult stem cells?

(cannot differentiate into any cell type) mostly used from bone marrow - these can differentiate into any type of blood cell and a few other cell types only.

problem with stem cells in medication?

some say it is unethical and shouldn`t be done.

name for plant stem cells?

meristematic cells (used to produce clones quickly)

uses of stem cells in plants?

medical treatment and disease resistant crops can be cloned (for food)

what are chromosomes?

found in the nucleus-thread like strands of DNA

numbers of chromosomes

you have 46 (23 mum 23 dad)

pairs in males and females

23 pairs in total (46individual) - 22 are the same in males and females however the 23rd is xy in males and xx in females

what is a gene

genes carry the instruction for making proteins within the cell. genes determine the characteristics and features of an organism.

what is DNA ?

Dna is a very long molecule, double helix shape, composed of bases and a sugar phosphate backbone

what are the bases in dna

C-G (remember Car in a Garage)

A-T(Apple in a Tree)

what is the sugar in the sugar phosphate backbone?

deoxyribose

gene definition

as hort section of DNA that codes for proteins.

name some proteins

Enzymes - control chem reactions

antibodies - protect us from diseases

Haemoglobin - carries oxygen round the body

hormones - chemical messages

RUBISCO - essential for photosynthesis

cell cycle?

three stages that a cell in an organism goes through during their life

what are the stages in a cell cycle?

1 - interphase

2- mitosis

3- cytokinesis

cell cycle - what happens

1 - G1 (the cell grows)

2- S (synthesis, cell copies its DNA)

3- G2 (cell gets even bigger)

4 - M (mitosis, cell division (has 4 parts)

what are the stages of mitosis?

Prophase, Metaphase, Anaphase, Telophase

Mitosis definition

a form of nuclear division which produces genetically identical copies of cells. (bacteria cannot because there is no nucleus)

mitosis means that…

each daughter cell has the same number of chromosomes as the parent cell. this is called a diploid number of chromosomes (in humans its 46)

when does mitosis occur?

during growth, repair, and asexual reproduction (in dome organisms)