BIOLOGY 1A03 Midterm 1 Test Questions and Answers Already Passed Latest Update 2025-
2026
Chloroplasts contain - Answers flattened and stacked thylakoid membranes, fiber-like. Contain
stacks of thylakoids within the bounds of the inner membrane called grana. Within thylakoids
there are pigments and enzymes that contribute to photosynthesis
How many cells are in the human body? - Answers ~3 trillion cells
Eukaryotic Cells - Answers organisms who have have a nucleus and other organelles inclosed
by a plasma membrane. are larger cells that are multi-cellular or unicellular and more complex.
Some structures that can be found are:
- nucleus (central organelle that stores DNA in cromatin form)
- nucleolus (part of the nucleus where rRNA is synthesized)
- membrane
- cytoskeleton
- ribosomes
- mitochondria
- cytoplasm + cytosol (cytoplasm is area contained within cellular membrane and cytosol is gel
like fluid that contains organelles)
- vacuoles and vesicles
- endoplasmic reticulum
Prokaryotic Cells - Answers Unicellular organisms that lack membrane bound organelles, most
noteworthy being the nucleus. Rather than membrane bound organelles, they contain distinct
regions.
Some of which include:
- nucleoid: central region of prokaryotic cell that contains all genetic information
- ribosomes
,- cell wall
- cell membrane
- capsule: some bacteria have a polysaccharide shell that surrounds the cell wall that allows
them to connect to other cells
- Fimbriae: hair-like projections that help with cell attachment
- Pili: pill-like structures that are involved with DNA synthesis and transfer
- Flagella: tail like structure that helps with movement
Microbiome - Answers a populaiton of microbiotic organisms within the body. ~10000 species
of microbes live within the human body
Where is DNA found in bacterial cells? - Answers In cicular chromosomes folded into many
loops. Also contain small circles of additional DNA called plasmids.
Streptococcus Salivarius - Answers a normal inhabitant of the upper respiratory tracts and oral
cavity. contribute to the formation of plaque
Staphylococcus Haemolyticus - Answers resides on our skin and contributes to skin flora of
humans. can be pathogenic when inside the body, can enter through cuts or wounds. can be
direct or indirect transmission*
Bacteroides Thetaiotaomicron - Answers Is a predominant intestinal bacteria - helps to
breakdown plant cells in the human body.
Cells - Answers A membrane bound structure containing macromolecules
4 classes of macromolecules - Answers 1. Nucleic Acids (ex. RNA/DNA)
2. Proteins (ex. structure, metabolic activities)
3. Phospholipids (ex. cellular membrane)
4. Polysaccharides (ex. plant cell wall)
Function of membranes - Answers Seperate an internal environment from the external
environment. Allows different environments to have different chemical compositions
What components form the structure of the cell membrane - Answers phospholipids: bilayer
composed of hydrophilic head (phosphate group + polar head) and hydrophobic hydrocarbon
chain. both respective sections mesh together. 16-18 carbons per chain.
, proteins: allow for movement of ions and larger molecules that would not be able to pass
through the bilayer through diffusion
What kind of barrier is the cellular membrane? - Answers semi-permeable
Saturated or Unsaturated Lipid? - Answers Saturated lipids contain only single bonds between
all carbon atoms in the hydrocarbon chain, "saturated" with H atoms. This allows for it to stack
nicely as structure is very uniform. Unsaturated lipids contain some double bonds between
carbon atoms which are seen as "kinks" in the chain. This prevents them from stacking nicely
which is why most unsaturated fats come in liquid form. ex. olive oil compared to butter.
Function of steroids in the membrane - Answers Steroids are a type of lipid (4 carbon ring
structure with a hydrophilic head and hydrophobic tail). Can either add to fluidity or take it away.
At warmer temperatues, its large structure prevents the cell membrane from being too fluid
decreasing fluidity but at low temperatues, prevents the cell membrane from freezing increasing
fluidity**
How do phospholipds adopt the membrane structure? - Answers Spontaneously, through the
use of chemical properties. Water molecules will interact with the head regions while the tails of
the phospholipds reject water and attract eachother. 2 main structures:
- bilayer (used for cellular membrane)
- micelles (important for the absorption of fat soluble vitamins)
Cell membrane fluidity - Answers phospholipds can move laterally within the cell membrane
lipid bilayer but they CANNOT flip from one layer to the other without a great use of energy as
that would involve pulling the heads away from eachother and away from water molecules.
Factors affecting fluidity - Answers 1. Unsaturated or saturated fatty acids - with the carbons
further apart in unsaturated they are more fluid + can't stack
2. Number of carbons in the fatty acid tail - more carbons = stronger intermolecular forces
between fatty acid tails which makes them more rigid
3. Temperature - as temp increases, vibrational frequency of atoms increases pushing their
distance further apart increasing fluidity
.4. The presence or absence of cholesterol
What is a lipid raft? - Answers microdomains of the cell membrane that assist with cell
functions. can have varying properties. ex. rafts holding macromolecules are significantly more
rigid.
Domain of cell membrane? - Answers cell membrane can be divided into different regions that
2026
Chloroplasts contain - Answers flattened and stacked thylakoid membranes, fiber-like. Contain
stacks of thylakoids within the bounds of the inner membrane called grana. Within thylakoids
there are pigments and enzymes that contribute to photosynthesis
How many cells are in the human body? - Answers ~3 trillion cells
Eukaryotic Cells - Answers organisms who have have a nucleus and other organelles inclosed
by a plasma membrane. are larger cells that are multi-cellular or unicellular and more complex.
Some structures that can be found are:
- nucleus (central organelle that stores DNA in cromatin form)
- nucleolus (part of the nucleus where rRNA is synthesized)
- membrane
- cytoskeleton
- ribosomes
- mitochondria
- cytoplasm + cytosol (cytoplasm is area contained within cellular membrane and cytosol is gel
like fluid that contains organelles)
- vacuoles and vesicles
- endoplasmic reticulum
Prokaryotic Cells - Answers Unicellular organisms that lack membrane bound organelles, most
noteworthy being the nucleus. Rather than membrane bound organelles, they contain distinct
regions.
Some of which include:
- nucleoid: central region of prokaryotic cell that contains all genetic information
- ribosomes
,- cell wall
- cell membrane
- capsule: some bacteria have a polysaccharide shell that surrounds the cell wall that allows
them to connect to other cells
- Fimbriae: hair-like projections that help with cell attachment
- Pili: pill-like structures that are involved with DNA synthesis and transfer
- Flagella: tail like structure that helps with movement
Microbiome - Answers a populaiton of microbiotic organisms within the body. ~10000 species
of microbes live within the human body
Where is DNA found in bacterial cells? - Answers In cicular chromosomes folded into many
loops. Also contain small circles of additional DNA called plasmids.
Streptococcus Salivarius - Answers a normal inhabitant of the upper respiratory tracts and oral
cavity. contribute to the formation of plaque
Staphylococcus Haemolyticus - Answers resides on our skin and contributes to skin flora of
humans. can be pathogenic when inside the body, can enter through cuts or wounds. can be
direct or indirect transmission*
Bacteroides Thetaiotaomicron - Answers Is a predominant intestinal bacteria - helps to
breakdown plant cells in the human body.
Cells - Answers A membrane bound structure containing macromolecules
4 classes of macromolecules - Answers 1. Nucleic Acids (ex. RNA/DNA)
2. Proteins (ex. structure, metabolic activities)
3. Phospholipids (ex. cellular membrane)
4. Polysaccharides (ex. plant cell wall)
Function of membranes - Answers Seperate an internal environment from the external
environment. Allows different environments to have different chemical compositions
What components form the structure of the cell membrane - Answers phospholipids: bilayer
composed of hydrophilic head (phosphate group + polar head) and hydrophobic hydrocarbon
chain. both respective sections mesh together. 16-18 carbons per chain.
, proteins: allow for movement of ions and larger molecules that would not be able to pass
through the bilayer through diffusion
What kind of barrier is the cellular membrane? - Answers semi-permeable
Saturated or Unsaturated Lipid? - Answers Saturated lipids contain only single bonds between
all carbon atoms in the hydrocarbon chain, "saturated" with H atoms. This allows for it to stack
nicely as structure is very uniform. Unsaturated lipids contain some double bonds between
carbon atoms which are seen as "kinks" in the chain. This prevents them from stacking nicely
which is why most unsaturated fats come in liquid form. ex. olive oil compared to butter.
Function of steroids in the membrane - Answers Steroids are a type of lipid (4 carbon ring
structure with a hydrophilic head and hydrophobic tail). Can either add to fluidity or take it away.
At warmer temperatues, its large structure prevents the cell membrane from being too fluid
decreasing fluidity but at low temperatues, prevents the cell membrane from freezing increasing
fluidity**
How do phospholipds adopt the membrane structure? - Answers Spontaneously, through the
use of chemical properties. Water molecules will interact with the head regions while the tails of
the phospholipds reject water and attract eachother. 2 main structures:
- bilayer (used for cellular membrane)
- micelles (important for the absorption of fat soluble vitamins)
Cell membrane fluidity - Answers phospholipds can move laterally within the cell membrane
lipid bilayer but they CANNOT flip from one layer to the other without a great use of energy as
that would involve pulling the heads away from eachother and away from water molecules.
Factors affecting fluidity - Answers 1. Unsaturated or saturated fatty acids - with the carbons
further apart in unsaturated they are more fluid + can't stack
2. Number of carbons in the fatty acid tail - more carbons = stronger intermolecular forces
between fatty acid tails which makes them more rigid
3. Temperature - as temp increases, vibrational frequency of atoms increases pushing their
distance further apart increasing fluidity
.4. The presence or absence of cholesterol
What is a lipid raft? - Answers microdomains of the cell membrane that assist with cell
functions. can have varying properties. ex. rafts holding macromolecules are significantly more
rigid.
Domain of cell membrane? - Answers cell membrane can be divided into different regions that
