Cell Biology

Muscle fiber

Fungal hypha

Chlamydomonas

Virus

The genome is completely rewritten

Specific genes are activated while others are silenced

Half of the chromosomes are discarded

The DNA is converted into RNA permanently

Millimeters ($mm$)

Centimeters ($cm$)

Nanometers ($nm$)

Meters ($m$)

Metabolism

Nutrition

Response

Excretion

Stage A

Stage B

Stage C

Stage D

It decreases the total surface area to minimize the risk of water loss.

It increases the $SA:V$ ratio, allowing for a more efficient exchange of materials and waste.

It keeps the total volume constant while significantly decreasing the metabolic demand of the cytoplasm.

It allows the cells to bypass the need for a plasma membrane by increasing internal volume.

The ability of a single cell to synthesize proteins.

The movement of a whole organism resulting from the coordination of muscle and nerve tissues.

The process of osmosis across a plasma membrane.

The replication of DNA before cell division.

X increases because the higher external salinity triggers an increase in the metabolic rate and waste production.

X increases because the cell must actively pump out salt ions that diffuse in from the environment.

X decreases because the reduced osmotic gradient results in a lower net influx of water into the cell.

X remains constant because the cell membrane is completely impermeable to water molecules.

Stage B is pluripotent; certain genes required for extra-embryonic development have been epigenetically silenced.

Stage B is totipotent; the cell has activated specific transcription factors to allow for any tissue type to form.

Stage B is multipotent; the cell has lost half of its total genome through selective DNA degradation.

Stage B is unipotent; the cell can now only express genes related to a single, specific functional role.

They both lack a nucleus.

They both challenge the idea that cells are small and simple.

They are both multicellular organisms.

They both consist of many individual cells fused together.

They are the main genomic DNA

They are membrane-bound organelles

They are small, circular pieces of extra-genomic DNA

They are found inside the nucleus

To store water

To produce ATP

To maintain cell shape and assist in movement

To synthesize proteins

Transmission electron microscope

Scanning electron microscope

Compound light microscope

Phase-contrast microscope

Cytoplasm

Nucleolus

Rough ER

Golgi apparatus

A glandular animal cell

A photosynthetic plant cell

A bacterial cell

A root hair cell

Transmission electron microscope

Scanning electron microscope

Compound light microscope

Atomic force microscope

Mitochondria : Grana

Chloroplast : Cristae

Golgi apparatus : Cisternae

Nucleus : Peptidoglycan

A solid layer of proteins with liquid lipids on top.

A bilayer of phospholipids with proteins embedded and able to move laterally.

A fixed structure of lipids and proteins held together by covalent bonds.

A series of protein channels surrounded by a carbohydrate shell.

$1 mm$

$10 mm$

$100 mm$

$0.1 mm$

Site of protein synthesis.

Increase surface area for respiration or cell wall synthesis.

Storage of genetic information.

Attachment to other cells.

Bipolar

Amphipathic

Ambivalent

Hydro-sensitive

Light microscopy

Freeze-fracture electron microscopy

Scanning tunneling microscopy

Simple magnifying glass

It allows tails to pack tighter

It makes the membrane more rigid

It prevents close packing, increasing fluidity

It makes the membrane thicker

Facing the outside of the cell

Facing the cytoplasm

Pointing toward each other in the center

Interacting with the phosphate heads

In the hydrophobic gap between the two leaflets of the phospholipid bilayer

In the region of the membrane that interacts with the aqueous environment

At the very center of the lipid bilayer, oriented away from the phosphate heads

Covalently bonded to the hydrophobic tails of adjacent integral proteins

Glycoproteins

Cholesterol

Peripheral proteins

Saturated fatty acids

The lipid bilayer changes its thickness to accommodate different proteins.

The proteins determine the specific functions of that membrane.

Each cell type has a unique genetic code for the lipid bilayer.

Some cells do not have enough energy to produce integral proteins.

Cholesterol fills the gaps created by the kinks, increasing the density and reducing permeability.

Cholesterol removes the kinks by saturating the double bonds.

Cholesterol increases the number of kinks to make the membrane more fluid.

Cholesterol binds covalently to the kinks to prevent them from moving.

A region with a high density of glycoproteins.

The hydrophobic interior of the lipid bilayer lacking integral proteins.

The presence of a thick layer of peripheral proteins.

A region where the membrane has been completely destroyed by freezing.

Regulating the movement of water via aquaporins.

Acting as a precursor for the synthesis of integral proteins.

Maintaining membrane integrity and fluidity across a range of temperatures.

Determining the cell's blood type markers.

Diffusion

Against the concentration gradient

Down the concentration gradient

Osmosis

Simple diffusion

Exocytosis

Osmosis

Endocytosis

It makes the cell too heavy

It makes transport of materials into the cell less efficient

It increases the energy produced by the cell

It prevents the cell from ever dividing

It increases

It decreases

It stays the same

It fluctuates

From the extracellular fluid to the cytoplasm via active transport

From the extracellular fluid to the cytoplasm via facilitated diffusion

From the cytoplasm to the extracellular fluid via simple diffusion

From the cytoplasm to the extracellular fluid via facilitated diffusion

The polar phosphate heads.

The hydrophobic hydrocarbon tails.

The peripheral proteins.

The glycoproteins.

Steroid hormones — Facilitated diffusion

Glucose — Simple diffusion

Protons ($H^+$) — Active transport via pumps

Large proteins — Simple diffusion

The concentration gradient of the solute

The number of available transport proteins in the membrane

The amount of ATP available in the cell

The thickness of the cell wall

The uptake of glucose via facilitated diffusion

The secretion of hormones like insulin

The osmosis of water into the cell

The diffusion of oxygen into the cell

It consists of a permanent open pore that allows specific ions through

It has specific binding sites for the solute and undergoes a change in shape

It is always a peripheral protein that does not span the membrane

It only moves molecules from the extracellular fluid to the cytoplasm

It was rich in oxygen and very stable

It was a reducing environment that could form organic compounds

It was devoid of any gases

It was exactly the same as it is today

Self-replication of molecules

Development of a nucleus

Catalysis of chemical reactions

Assembly of organic molecules into polymers

Nitrogen gas ($N_2$)

Ammonia ($NH_3$)

Nitric acid

Nitrate

Cells have been shown to arise only from pre-existing cells

It was never a popular theory

All life is now known to be made of inorganic matter

DNA was found to be the only way life can start

The inner membrane has a chemical composition similar to bacterial membranes.

Both membranes are identical in structure and protein content.

The outer membrane is composed of peptidoglycan like a bacterial cell wall.

The space between the membranes contains the cell's main DNA.

Acting as an enzyme to facilitate chemical reactions.

Forming the structural framework of the cell wall.

Providing the energy required for active transport.

Maintaining the osmotic balance of the protocell.

It may have originated from an endosymbiotic relationship with spirochete bacteria.

It evolved as an extension of the cell's cytoskeleton to catch food.

It was developed from the same ancestral bacterium as the mitochondrion.

It is an outfolding of the nuclear envelope that became motile.

Because Tetrahymena is not considered a living organism.

Because the differences are very minor and clearly derived from the standard code.

Because Tetrahymena uses RNA instead of DNA as its genetic material.

Because the genetic code is not actually used by ciliates.

A fossilized prokaryote found in ancient rocks.

An abiotic precursor of a living cell that had a membrane-like structure and maintained an internal chemistry.

A type of virus that only infects bacteria.

The first multicellular organism to appear in the fossil record.

Only once (primary endosymbiosis).

Dozens of times in different environments.

Every time a cell divides.

Once for every different pigment type (chlorophyll a, b, and c).

They begin to uncoil

They continue to shorten

They replicate immediately

They are ejected from the cell

To produce more white blood cells to fight infection

To replace damaged or dead cells with new identical cells

To change the DNA of the damaged cells

To shrink the wound through muscle contraction

They are used to build the cell wall

They break down and disappear

They replicate for the next division

They pull the nucleus to the side of the cell

Interphase is the shortest part of the cycle

Interphase is the longest part of the cycle

Mitosis does not happen in most cells

The microscope kills cells in mitosis

$G_1$ and $G_0$ phases

S phase only

$G_1$ and S phases

$G_2$ and Mitosis

Prophase

Metaphase

Anaphase

Telophase

The ratio increases, making the cell more efficient and less likely to divide.

The ratio decreases, making the cell less efficient and triggering division.

The ratio stays the same, so it has no effect on division.

The ratio decreases, and the cell stops all metabolic activity.

The process where a benign tumor remains localized to one tissue.

The movement of cells from a primary tumor to other parts of the body to form secondary tumors.

The mutation of a proto-oncogene into an oncogene.

The programmed death of a cell after its telomeres have shortened.

2 cells with 6 chromosomes each.

2 cells with 12 chromosomes each.

2 cells with 24 chromosomes each.

4 cells with 6 chromosomes each.

It is the site where the new cell wall is deposited.

It is an invagination of the plasma membrane that eventually pinches the cell into two.

It is the structure that pulls the chromosomes to the poles.

It is the gap that forms between homologous chromosomes during prophase.

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