AQA GCSE Biology Cell Structure

animal cells have

nucleus, cytoplasm, cell membrane, mitochondria, ribosomes, nucleus

nucleus

controls all the activities of the cell

cytoplasm

liquid inside cell where chemical reactions take place

cell membrane

controls the passage of substances in and out of cell

mitochondria

where oxygen is used and most of the energy released during respiration

ribosomes

where protein is synthesised

cell wall

made of cellulose, strengthens plant cell

chloroplasts

green cells containing chlorophyll

vacuole

space in cytoplasm filled with cell sap, helps to keep plant cell rigid

plant cells have

nucleus, cytoplasm, cell membrane, cell wall, mitochondria, vacuole, chloroplasts

animal cells have

nucleus, cell membrane, mitochondria, ribosomes, cytoplasm

Prokaryotic

An organism, small simple cell, whose cells do not have an enclosed nucleus

Eukaryotic

Complex cells containing organelles with specific functions

Prokaryotic examples

Bacteria and Archaea

Eukaryotic examples

animals, plants, fungi, protists

Flagella

whiplike tails found in one-celled organisms to aid in movement

unicellur

one cell

an animal cell does not have

chloroplasts, vacuole or a cell wall

stem cells

undifferentiated cells which if given the right instructions can turn into any type of specialised cell

stem cells are mostly made of

bone marrow

stems cells can be found in

meristems

Benefits of stem cells

Treat cancer

Cure disease

Replace damaged organs

help preserve species

two main types of stem cells

Embryonic stem cells. Embryonic stem cells come from human embryos that are three to five days old.

Adult stem cells. These stem cells come from developed organs and tissues in the body. They're used by the body to repair and replace damaged tissue in the same area in which they are found.

how are stem cells used to grow meat in a lab

taken from skeletal muscle of cows. cell is injected with a chemical to become a muscle cell. then cells divide and grow in a petri dish to produce the tissue.

advantages of stem cells instead of embryos

embryos won't die

difference between stem cells and specialised body cells

sc: can be chemically changed into any cell

are undifferentiated

only found in embryos

sb: the potential to be any type of cell

are differentiated

renew slower than a stem cell

What is differentiation?

The process by which a cell changes to become specialised for its job

nerve cells

to carry electrical signals from one part of the body to another. long to cover more distance. branched connections to connect from one nerve cell to another

sperm cell

Male sex cell

muscle cell

long and slender and contains fibers that aid in contracting and relaxing

egg cell

female reproductive cell

phloem cell

transport sugar produced in photosynthesis. found in plants.

xylem cell

transport water and mineral ions from roots to leaves in plants, supports plant.

palisade cells

a specialised cell found in plants. carry out photosynthesis for the plant has many chloroplasts. tall thin shape

root hair cell

absorbs water and nutrients from the soil. sent from the root hair cell up through the roots to the rest of the plants. has long thin hairs

scanning electron microscope

a microscope that produces an enlarged, three-dimensional image of an object by using a beam of electrons rather than light. expoenisve

light microscope

An optical instrument with lenses that refract (bend) visible light to magnify images of specimens.cheaper

transmission electron microscope

An electron microscope used to study the internal structure of thin sections of cells. expensive

magnification equation

size of image divided by actual size of the object

Label the parts of a microscope

eyepiece

body tube

arm

cource adjustment knob

fine adjustment knob

base

revoulving nose piece

objective lens

stage clips

stage

diaphram

light source

what solution do you use in the onion experiment

iodine because it colours the different parts of a cell and you can see it under a microscope

What does the mitochondria do in sperm cells

to release energy for its journey