Cells Flashcards
What are eukaryotes?
Organisms that are made up of eukaryotic cells.
Sub cellular structures
The different parts of a cell.
Nucleus
Contains genetic material that controls the activities of the cell.
Cytoplasm
gel-like substance where most of the chemical reactions happen. It contains enzymes that control chemical reactions.
Cell membrane
Holds the cell together and controls what goes in and out.
Mitochondria
these are where most of the aerobic respiration take place.
Ribosomes
these are where proteins are made in the cell
Cell wall
Made of cellulose. It supports the cell and strengthens it.
Permanent vacuole
Contains cell sap. It helps to give the plant cell shape.
Chloroplast
Where photosynthesis occurs. They contain a chlorophyll(green) which absorb the sunlight.
What bacteria does not have?
Chloroplast and mitochondria. Also it does not have a nucleus, instead single circular strand of DNA that floats in the cytoplasm.
Plasmid
Small rings of DNA in bacteria cell.
Cell differentiation
Is the process by which a cell changes to become specialized for its job. They develop different sub cellular structures and turn into different types of cells. This allows them to carry out specific functions.
Stem cell
Undifferentiated cell that can become any type of cell.
Differentiation trough out life of animal and plant
Most differentiation occurs as an organism develops. In most animal cells the ability to differentiate is lost in early stages of life. Lots of plant cells do not lose this ability.
Mature animals use differentiation to…..
repair and replace cells, such as skin or blood cells.
Sperm cell
- sperm cells-contain half of genetic info in nucleus.
- streamlined shape
- long tail to swim to the egg
- contains mitochondria to provide the energy needed
- contains enzymes, which digest cell membrane of egg.
Root hair cell
- absorbing water and minerals
- gives plant large surface area
- does not contain chloroplast(no sunlight)
- large permanent vacuole, speeds up the osmosis
Xylem is found in…
stem of the plant.
Eukaryotic cells
Have nucleus, containing genetic information. It includes animal and plant cells.
Prokaryotic cells
Genetic material is not in nucleus. Can be in form of plasmid or loop of DNA.
Prokaryotic cells properties:
- much smaller than eukaryotes
- have a cell wall (bacterial no plant)
Plant cell have a regular….
shape.
Muscle cell can…
contract.
- protein fibers which can change the length
- mitochondria provide energy
Muscle cell work together to…
from a muscle tissue.
Xylem transport…
water and dissolved minerals to leaves.
Xylem have very thick walls containing…
ligin, which provides support to plant.
Xylem has no…
internal structures, so water can easily flow.
Phloem carry…
dissolved sugars up and down the plant.
Phloem vessel cell have no…
nucleus only limited cytoplasm.
Algae
Simple aquatic organisms, making their own food and are similar to a plant cell.
Algae and plant cells have always…
a cell wall.
Fat cells form…
adipose tissue.
Fat cell adaptations
- a small amount of cytoplasm to store a large amount of fat
- few mitochondria as it does not need a lot of energy
- they can expand up to 1000 times its original shape
Cone cell (human eye)
- make possible for humans to see colours
- found in retina
Cone cell (human eye) adaptations
- the outer segment contains a special chemical, a visual pigment
- middle segement is packed full of mitochondria, provide energy needed to refrom visual pigment
- finall part is made of synpase that conect to a optic nerve
