B1 Flashcards
Are animals and plant cells prokaryotes or eucaryotes?
Eucaryotes
Are bacteria cells eukaryotes or prokaryotes?
Prokaryotes
What type of cells are multicellular organisms?
Animal and plant cells have
What type of cells are unicellular organisms?
Bacteria cells
Name 5 sub cellular structures that are in Both an8mal and plant cells?
Cell membrane
Nucleus
Cytoplasm
Mitochondria
Ribosome
Name the 3 sub cellular structures that are in a plant cell but not an animal cell?
Cell wall
Permanent vacuole
Chloroplasts
Name the 7 sub cellular structures in a bacterial cell?
Cell wall
Cell membrane
Plasmids
Cytoplasm
Ribosome
Nucleoid
Flagellum
What is the function of a cell membrane?
Controls which substances can pass in and out of a cell
What is the function of a nucleus?
Contains the genetic material (DNA) and controls the functions of the cell
What is the function of cytoplasm?
It is where the chemical reactions take place
What is the function of mitochondria ?
Provides cells with the energy they need to function through aerobic respiration.
What is the function of the ribosomes ?
It is the site of protein synthesis
What is the function of a cell wall?
It is made of cellulose which is a very strong substance which gives the cell strength in structure.
What is the function of the permanent vacuole?
It contains the cell sap (mixture of sugars and salts)
What is the function of the Chloroplasts ?
It is the site of photosynthesis so it produces the sugars needed for the cell
What is the function of the nucleiod?
Contains the genes that the cell needs to survive +reproduce
What is the function of the plasmids?
It has extra genes (DNA) that is different to the nucleiod DNA
What is the function of the flagellum?
To propel the bacteria
How is the genetic information in a eukaryotic cell stored?
Within the nucleus arranged in chromosomes
Describe the structure of the cytoplasm?
Fluid component of the cell which contains organelles, enzymes and nutrients
When looking at chloroplasts under a light microscope why do they appear green?
They contain chlorophyll which is a green pigment
What is the prokaryotic cell wall made of ?
Peptidoglycan
What is a haploid cell?
A cell that contains a single copy of each chromosome (half the number of chromosomes).
e.g 23 chromosomes in humans
What is a diploid cell?
A cell that contains 2 copies of each chromosome ( a full set of chromosomes)
e.g 46 chromosomes in humans
What are gametes?
Reproductive cells ( they are haploid cells)
Explain sexual reproduction in terms of chromosome number ?
2 haploid gametes fuse resulting in an embryo that has 2 chromosomes for each gene and 2 copies of each allele
How are egg cells adapted for their function?
Cytoplasm contains nutrients for the developing embryo.
Cell membrane hardens after fertilisation to prevent any other sperm entering the egg
How are sperm cells adapted to their function ?
Tail enables movement.
Acrosome contains enzymes that digest the egg cell membrane
Where are ciliates epithelial cells found?
Found in the lining of structures such as the respiratory tract or the uterus.
Describe the function of ciliated epithelial cells lining the airway?
Move in synchronised waves to move mucus up to the back of the throat so it can be swallowed
What is magnification?
The number of times bigger an image appears compared to the size of the object
How can the total magnification of an image be calculated from lens powers?
Total magnification = eyepiece lens magnification x objective lens magnification
How do you calculate magnification of an image?
I A M
Image size, Actual size, Magnification
What is resolution?
The smallest distance between 2 objects that can be distinguished
How does a light microscope work?
Passes a beam of light through a specimen which travels through the eyepiece lens allowing the specimen to be observed
What are 4 advantages of a light microscope ?
Inexpensive
Easy to use
Portable
Observe both dead and living specimens
What are the disadvantages of a light microscope ?
Limited resolution
How does an electron microscope work?
It uses a beam of electrons which are focused using magnets. The electrons hit a fluorescent screen which emits visible light, producing an image.
Name the two types of electron microscope?
Transmission electron microscope (TEM)
Scanning electron microscope (SEM)
What are the advantages of electron microscopes?
Greater magnification and resolution
Why do electron microscopes have a greater magnification and resolution?
They use a beam of electrons which has a shorter wavelength than protons of light
How have electron microscopes enabled scientists to develop their understanding of cells?
• Allow small sub-cellular structures (e.g. mitochondria, ribosomes) to be observed in detail
• Enable scientists to develop more accurate explanations about how cell structure relates to function
What are the 4 disadvantages of electron microscopes?
Expensive
Not portable
Require training to use it
Only dead specimens can be observed
How do you convert from m to mm?
× 1000
How do you convert from m to ym?
× 1 000 000
How do you convert from m to nm?
× 1 000 000 000
How to you convert from nm to m?
÷ 1 000 000 000
How do you convert from m to pm?
× 1 000 000 000 000
