Biology Revision S3 Flashcards
Cell Organelles: What is the function of the nucleus in both animal and plant cells?
It controls the cell and contains DNA.
Cell Organelles: What is the function of the Cell Membrane in both animal and plant cells?
It controls exit and entry of substances.
Cell Organelles: What is the function of the Cytoplasm in both animal and plant cells?
Chemical reactions happen here.
Cell Organelles: What is the function of the Ribosomes in both animal and plant cells?
Produces proteins.
Cell Organelles: What is the function of the Mitochondria in both animal and plant cells?
Where respiration happens and energy is released.
Cell Organelles: What is the function of the Cell wall in plant cells?
helps support the plant cell
Cell Organelles: What is the function of the Chloroplasts in plant cells?
Absorb light for photosynthesis.
Cell Organelles: What is the function of the Vacuole in plant cells?
stores water and supports the cell.
What is the function of the cytoplasm?
The cytoplasm contains enzymes which control reactions in the cell.
What is differentiation in plant and animal cells?
As an organism develops cells differentiate to form different types of specialised cells. As a cell differentiates it gets different sub-cellular structures that enable it to carry out a particular function.
What are stem cells and where are they found in animal and plant cells?
Human stem cells can be found in embryos, the umbilical cord and bone marrow.
Stem cells can differentiate into other cell types.
Stem cells from embryos are the most useful to scientists because they are capable of turning into any cell type.
How does bacteria multiply?
DNA including plasmids replicate. DNA moves to each end of the cell and a new cell wall begins to form.
The cell splits and two new daughter cells are formed.
What are stem cells used for?
Medicine uses adult stem cells to cure disease.
Embryonic stem cells could be used to replace faulty cells in sick people.
What are eukaryotic and prokaryotic cells?
Eukaryotic cells are complex and include animal and plant cells.
Prokaryotic cells are much smaller and simpler and include bacteria.
What is a chromosome and where they are found within the cell?
Chromosomes are found in the cell nucleus. They are made from DNA.
What is diffusion and osmosis?
Diffusion is the random movement of a substance form a high to low concentration.
Osmosis is the movement of water from an high area concentration to an area of low water concentration.
How are leaves adapted for exchange?
Leaves have exchange surfaces underneath them that are covered in little holes called stomata.
The flattened shape of the leaf helps with a large surface area.
What is the function of the cell membrane?
the cell membrane controls the entry and exit of substances in the cell.
What is the function of the Chloroplasts?
The Chloroplasts absorb light for photosynthesis.
What is the function of the nucleus?
The nucleus contains the genes.
Where does respiration takes place- mitochondria
Respiration takes place in the mitochondria.
Name three types of specialised cells.
Three specialised cells are, Sperm Cell, Palisade Cell and Nerve Cell.
What part of a cell can only be found in Plant cells?
Chloroplasts.
Name two things that light microscopes use to form an image.
Light and lenses.
Describe what an electron microscope uses to form an image.
They use electrons instead of light.
Give two advantages of an electron microscope to a light microscope.
They have a higher magnification and a higher resolution.
Define the term resolution.
Resolution is the ability to distinguish between two points.
Name 2 cell parts that can be seen with an electron microscope but not with a light microscope.
Ribosomes and plasmids
Write down the formula for magnification.
magnification= image size divided by the real size.
What is the symbol for micrometers?
um.
Explain why standard form is useful.
It uses less zeros.
What are chromosomes made from?
DNA.
How many chromosomes does a human body cell have?
46.
How many chromosomes does a human gamete have?
23.
Give the name for the part of the cell cycle when cell division happens.
Mitosis
Give 2 uses of mitosis in multicellular organisms.
Grow cells and replace damaged cells.
How many cells are produced at the end of the cell cycle?
2
Name the 2 main stages of the cell cycle.
Growth and DNA replication and Mitosis.
Describe the appearance of DNA in a cell which is not dividing.
The DNA is spread out in long strings.
Describe what must happen in a cell before it divides.
It has to grow and increase the amount of sub-cellar structures.
Explain why DNA needs to be duplicated.
DNA needs to be duplicated so there’s one copy for each new cell.
Describe the appearance of a chromosome after the DNA has duplicated.
It is an X- shape.
Describe the main stages of mitosis.
Chromosomes line up at the centre of the cell
Cell fibres pull the chromosomes apart and the two arms go to opposite ends of the cell.
Membranes form around each set of chromosomes. These become the nuclei of 2 new cells.
The cytoplasm and cell membrane divide.
The cell has produced two new daughter cells that are identical to each other and the parent cell.
What type of cell makes proteins?
Ribosomes.
