biology 1
what are the two types of cells?
eukaryotic (plant and animal), prokaryotic (bacteria)
what are the differences between eykaryotic and prokaryotic cells?
prokaryotic are much smaller, eukaryotic contain membrane bound-organelles and a nucleus containing genetic material
what is the prokaryotic cell wall composed of?
peptidoglycan
how is genetic information stored in a prokaryotic cell?
found free within the cytoplasm as chromosomal DNA and plasmid DNA
what are plasmids?
small circular loops of DNA found free in the cytoplasm and separate from the main DNA and they carry genes that provide genetic advantages
what are chromosomes madeup of?
DNA molecules combined with proteins, they contain genes which provide the instructions for protein synthesis
what are the three main stages of the cell cycle?
1. replication of DNA and synthesis of organelles
2. mitosis
3. division of cell
what is a gene?
a section of DNA which codes for a protein
why is mitosis important?
it produces identical cells which all have the same genetic information and produces additional cells for growth and repair
how is a sperm cell adapted to its function?
has a tail and is very streamline, which helps it swim to the egg
what is therapeutic cloning?
producing an embryo that has the same genes as a patient
list two advantages of therapeutic cloning
helps when skin is damaged and replaces wounded cells, helps with condition such as paralysis and diabetes
list two disadvantages of therapeutic cloning
potential life is killed and there may be a shortage of donors/eggs
what is active transport?
the movement of substances from a dilute solution to a more concentrated solution with the use of energy from respiration
what is diffusion?
the spreading out of particles of any substance in solution, of particles of a gas, resulting in net movement from an area of higher concentration to an area of lower concentration
what is osmosis?
the diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane
what are all the parts of an animal cell?
nucleus, cytoplasm, cell membrane, mitochondria
what are all the parts of a plant cell?
nucleus, cytoplasm, cell membrane, mitochondria, cell wall, vacuole, chloroplasts
what is an adult stem cell?
a type of stem cell that can form many types of cells
what is cell differentiation?
the process where a cell becomes specialised to its function
what is the vacuole?
an organelle that stores cell sap
what is an organelle?
a specialised structure found inside a cell
what is the nucleus?
an organelle found in most eukaryotic cells that contains the genetic material of the cell and controls the activities of the cell
what is the cell membrane?
a partially permeable barrier that surrounds the cell
what is a cell wall?
an outer layer made of cellulose that strengthens plant cells
what are chloroplasts?
an organelle which is the site of photosynthesis
what is the concentration gradient?
the difference in concentration between two areas
what is the eyepiece lense?
the lens you look through that initially magnifies the specimen
what is the function of the objective lenses in a light microscope?
magnifies the lense further and allows the magnification to be changed
what is the purpose of the stage in a light microscope?
supports the slide with the specimen
what is magnification?
how much bigger an image appears compared to the original object
what is resolution?
the ability to distinguish two different points in a specimen
what is mitochondria?
an organelle which is the site of respiration
what is an embryonic stem cell?
a type of stem cell that can differentiate into many types of human cells
what are specialised cells?
cells that are adapted to perform a specific function
what is the cell cycle?
a series of stages preparing the cell for division
what are the three main stages of the cell cycle?
interphase, mitosis and cytokinesis
what happens during interphase?
the cell grows in size and synthesizes proteins and organelles needed for division, dna replication occurs, resulting in two identical copies of each chromosome then the cell continues to grow and prepares for mitosis
what happens during mitosis?
the division of the nucleus where the duplicated chromosomes are separated and distributed into two nee nuclei
what is mitosis further divided into?
prophase, metaphase, anaphase and telophase
what happens during prophase?
the DNA condenses, becoming visible as chromosomes and the nuclear envelope breaks down
what happens during metaphase?
the duplicated chromosomes line up along the center of the cell, also known as the equator or metaphase plate
what happens during anaphase?
sister chromatids, which are identical copied of chromosomes, separate and are pulled to opposite poles of the cell by splindle fibers
what happens during telophase?
the separated chromosomes reach the poles of the cell, a nuclear envelope reforms around each set of chromosomes and the cell begins to divide
what happens during cytokinesis?
this is the final stage where cytoplasm and cell membrane divide, resulting in two separate daughter cells.
what is the purpose of the cell cycle?
to enable cells to replicate themselves, producing two identical daughter cells
what is a stem cell?
an undifferentiated cell that can divide to produce many specialised cells of the same type
oxygen is taken into the cells by the process of?
diffusion
cells need oxygen for?
respiration
the parts of cells that use up the most oxygen are the?
mitochondria
some cells produce oxygen in the process of?
photosynthesis
list two examples of active transport
absorption of ions in plant roots and absorption of sugar in the small intestine