b1 cells

Created by

bibi

Cards (99)

What is the basic unit of life?
Cells
What can be seen with a normal light microscope?
Cells and possibly the nucleus
What does an electron microscope allow us to see?
Finer details of subcellular structures
How do we calculate the actual size of a cell?
By dividing the image size by the magnification
What are the two main groups of cells?
Eukaryotic and prokaryotic cells
What characterizes eukaryotic cells?
They have a nucleus containing DNA
Where is DNA found in prokaryotic cells?
In a ring called a plasmid
What are the functions of the cell membrane and cell wall?
Cell membrane: Keeps everything inside the cell and is semi-permeable
Cell wall: Provides a rigid structure, found in plant cells and most bacteria
What is the cytoplasm?
The liquid that makes up the cell where most chemical reactions occur
Where does respiration take place in a cell?
In the mitochondria
What is the role of ribosomes in a cell?
They assemble or synthesize proteins
What do chloroplasts contain and what is their function?
They contain chlorophyll and are where photosynthesis takes place
What is a permanent vacuole in plant cells used for?
To store sap
How do bacteria multiply?
By binary fission
If we start with one bacterium, how many would we have after one hour?
64 bacteria
What is the formula to calculate the number of bacteria after a certain time?
Number of bacteria = \(2^n\), where \(n\) is the number of divisions
What is the purpose of using aseptic technique in culturing bacteria?
To prevent contamination of the culture
How do we incubate the culture after preparing it?
At 25°C
How do we calculate the area of a circle in the context of bacterial growth?
Using the formula \(A = \frac{\pi d^2}{4}\)
What is the genetic material in eukaryotic cell nuclei?
DNA stored in chromosomes
How many pairs of chromosomes do humans have?
23 pairs
What are gametes and how many chromosomes do they have?
Gametes have 23 chromosomes, not in pairs
What is the process by which new cells are made for growth and repair?
Mitosis
What are the steps of mitosis?
Genetic material is duplicated
Number of ribosomes and mitochondria doubles
Nucleus breaks down
Chromosome pairs are pulled to opposite sides
New nuclei form around copied chromosomes
Two identical cells are produced
What are stem cells?
Cells that haven't yet specialized
Where are stem cells found in humans and animals?
In embryos and bone marrow
How can stem cells be used in medicine?
To combat conditions like diabetes and paralysis
What is cloning in the context of stem cells?
Making clones to harvest stem cells that won't be rejected
What are the ethical considerations of cloning?
Potential for misuse in humans
Concerns about identity and individuality
Risks of genetic defects
Impact on biodiversity
What is diffusion?
The movement of molecules from high to low concentration
What is osmosis?
The diffusion of water across a semi-permeable membrane
What happens to a cell in a hypertonic solution?
Water moves out, decreasing its mass
What factors can increase the rate of diffusion and osmosis?
Increasing concentration difference, temperature, or surface area
What is the practical procedure for investigating osmosis using potatoes?
Cut equal-sized cylinders from a potato
Weigh them and place in sugar solutions
After a day, weigh again
Calculate percentage change in mass
Plot results against sugar concentration
Determine concentration with no change in mass
What is active transport?
Movement of substances against a concentration gradient using energy
How do carrier proteins function in active transport?
They use energy to move substances through the membrane
What are the two types of cells in living organisms?
Prokaryotic and eukaryotic
What type of cells are animal and plant cells?
They are eukaryotic cells
What are the main components of eukaryotic cells?
Cell membrane
Cytoplasm
Nucleus containing DNA
What type of cells are bacterial cells?
Prokaryotic cells