Cells Flashcards
What are cells?
Cells are the building blocks of all living things
Every organism on the planet is made of cells but different organisms have different cell structures
Cells are the smallest unit of life
What is in an animal cell-this includes humans as well?
Cell membrane controls movement of substances into and out of the cell
Nucleus controls all activities of the cell - contains the genes on chromosomes
Cytoplasm-chemical reactions needed for life occur in this liquid gel
Ribosomes-all the proteins needed for the cell are synthesised here
Mitochondria - where oxygen is used and most of the energy is released during respiration
What is in a plant cell?
Cell membrane
Cell wall - made of cellulose forms rigid non-living box around cell to strengthen and provide support
Chloroplast - contains chlorophyll, green substance that absorbs light energy to make food by photosynthesis
Vacuole -large space containing cell sap - helps keep cells rigid to support the plant
Cytoplasm
Ribosomes
Mitochondria
Nucleus
What are root hair cells?
On the surface of plant roots
Specialised to absorb water and minerals
Grow into long hairs that stick out into the soil
Gives plant big surface area to absorb water and mineral ions from soil
What are sperm cells?
Specialised cells get the male DNA to the female DNA - reproduction
long tails
Streamlined head to help it swim to the egg
Lots of mitochondria to provide energy to do this
Contains enzymes in its head to digest through egg cell membrane
What are nerve cells?
Specialised for Rapid signalling
Send out electrical signals from one part of body to another
Very long
Branched connections at ends to connect to other nerve cells to form a network throughout the body
What are muscle cells?
Specialised for contracting quickly
Quite long
Lots of Mitochondria in them to transfer energy to contract
What are prokaryotes?
Small simple cells e.g. Bacteria
It is a single called organism
What are eukaryotes?
Complex cells including all animal and plant cells
They are organisms made up of eukaryotes
What is a bacterial cell?
Bacteria are prokaryotes
Cytoplasm
Cell membrane
Cell wall
No true nucleus
A single strand of DNA floating freely in the cytoplasm
One or more small thing of DNA called plasmids
What is a specialised cell?
One that performs a specific function
Most cells in an organism are specialised
A cell structure helps it to carry out its special function and can look very different
What is cell differentiation?
The process by which a cell changes to become specialised to do one job
As cells change they develop different sub cellular structures and turn into different types of cells
Mostly occurs as organism develops
In most animal cells the ability to differentiate is lost once they are specialised
What is a phloem and xylem cells?
Specialised for transporting substances
Form phloem and xylem tubes to transport substances e.g. Food and water around plants
To form tubes cells are long and joined end to end
Xylem are hollow in centre
Phloem have very few sub cellular structures so substances can flow through them.
Describe a palisade cell?
A palisade cell has many chloroplasts for photosynthesis
