Cell Biology, Histology, Neurobiology, and Organismal Physiology Flashcards

Comprehensive fill-in-the-blank practice flashcards covering cell cycle regulation, mitosis, eukaryotic evolution, multicellularity, tissue architecture, cell junctions, neurophysiology, muscle contraction, and plant and fungal structures.

In prokaryotic cells such as bacteria and archaea, cell division to make two daughter cells occurs by __________.

binary fission

In eukaryotic cells, the division of the nucleus where chromosomes separate into two nuclei is called __________.

mitosis

In eukaryotic cells, the division of the cytoplasm into two separate cells is called __________.

cytokinesis

During the eukaryotic cell cycle, the DNA content of the nucleus is replicated during the __________ of interphase.

S phase

The gap phase between M phase and S phase where cell size and protein content increase is the __________.

G1 phase

Regulatory proteins whose levels fluctuate with a particular phase of the cell cycle are known as __________.

cyclins

Kinases that are always present within the cell but are active only when bound to their respective cyclin are __________.

CDKs

Proteins that inhibit cell division are known as __________.

tumor suppressors

Pairs of chromosomes of the same type carrying the same set of genes are called __________.

homologous chromosomes

Two double helix copies of a chromosome made by DNA replication are called __________.

sister chromatids

The first stage of mitosis, characterized by the appearance of visible, condensed chromosomes, is __________.

prophase

During the __________ stage of mitosis, the nuclear envelope breaks down and microtubules attach to chromosomes.

prometaphase

During metaphase, chromosomes are aligned in the __________ of the cell.

middle

Sister chromatids separate during the __________ stage of mitosis.

anaphase

The microtubule organizing center for animal cells is the __________.

centrosome

The ring of actin filaments that promotes division of one cell into two is the __________.

contractile ring

The cell wall in bacteria is made up of a complex polymer of sugars and amino acids called __________.

peptidoglycan

Through endosymbiosis, eukaryotic cells evolved from an ancestral __________.

archaeon

An organism structure where multiple cells stick together and cooperate, but most or all cells keep full reproductive and functional capacities with very little specialization, is called __________.

simple multicellularity

The three essential requirements that must be met for a lineage to evolve complex multicellularity are adhesion, communication, and __________.

differentiation

The movement of a fluid driven by pressure differences that allows complex bodies to overcome the distance limits of diffusion is __________.

bulk flow (also called bulk transport)

Animal cells are more vulnerable to osmotic lysis in a hypotonic environment than bacterial cells because animal cells lack a __________.

cell wall

A collection of cells that work together to perform a specific function is a(n) __________.

tissue

The most abundant and widely distributed tissue type in the human body is __________.

connective tissue

The most abundant protein in the human body, providing tensile strength through bundled fibers, is __________.

collagen

The specialized form of extracellular matrix supporting all epithelial tissues, also known as the basement membrane, is the __________.

basal lamina

Mutations in collagen's primary structure lead to a loss in tensile strength, causing cases of __________.

osteogenesis imperfecta

Glycosaminoglycans (GAGs) resist compression forces because their secreted negative charge attracts water and __________.

$$\text{Na}^+$$

Calcium-dependent adherence proteins used in the adhesion of animal cells are called __________.

cadherins

Transmembrane proteins on the surface of the cell that enable cells to adhere to the extracellular matrix are __________.

integrins

A junction in animal epithelium that seals adjacent membranes, preventing fluid leakage between cells, is a __________.

tight junction

Direct connections between cell membranes of adjacent animal cells allowing transport of small ions and molecules between cytosols are __________.

gap junctions

Connections between cell membranes of adjacent plant cells that allow transport of materials including RNA and proteins between cytoplasms are __________.

plasmodesmata

The fiberlike extensions from a neuron cell body that receive signals from other nerve cells are __________.

dendrites

The junction of a nerve cell body and its axon that initiates an action potential is the __________.

axon hillock

The steady resting membrane potential of an unstimulated neuron is about __________.

-70 mV

The critical depolarization voltage required for an action potential to occur is __________.

$$-55\,\text{mV}$$

To maintain concentration gradients, the $\text{Na}^+/\text{K}^+$ pump uses ATP to move $3\,\text{Na}^+$ out and __________ in.

2 K+

During an action potential, the rapid depolarization phase is caused by the rush of ions through voltage-gated __________ channels.

Na+

At the axon terminal, depolarization opens voltage-gated channels that allow __________ to flow in, triggering vesicle exocytosis.

Ca²+

A long rodlike structure in muscle fibers that contains parallel arrays of actin and myosin filaments is a(n) __________.

myofibril

The region of myofilaments within muscle myofibrils that spans from one Z disc to the next is a(n) __________.

sarcomere

The protein that moves tropomyosin away from myosin-binding sites on actin is __________.

troponin

A modified form of the endoplasmic reticulum surrounding the myofibrils of muscle cells that stores calcium is the __________.

sarcoplasmic reticulum

Upon death, the lack of ATP synthesis prevents the release of actin from myosin heads, causing __________.

rigor mortis

The stage in the muscle cross-bridge cycle in which the myosin head pivots and generates a force is the __________.

power stroke

Plasma membrane invaginations that connect calcium channels to release channels in muscle cells are called __________.

T-tubules

The outward pressure that a cell's contents exert against its cell wall when the cell takes in water is called __________.

turgor pressure

A small plant with a high surface area to volume ratio that lacks vascular tissue is a(n) __________.

bryophyte

In vascular plants, water transport is primarily performed by xylem, while carbohydrate transport is performed by __________.

phloem

The cell walls of fungi are made up of a modified polysaccharide containing nitrogen called __________.

chitin

A network of branching hyphae in fungi is called a(n) __________.

mycelium

In plant cell walls, compression resistance and charged ion attraction are provided by pectin jellies and __________ ropes.

cellulose