Cell Biology Flashcards

Fill-in-the-blank flashcards covering major points from the lecture on cell biology, including cell structure, transport, organelles, specialization, division, and historical discoveries.

The smallest unit of living matter that can exist by itself is the __.

cell

Organisms such as bacteria consist of only a __ cell.

single

A micron is equal to about one __ of a meter.

millionth

The average human cell is roughly __ microns in diameter.

10

The branch of biology that studies cells is called __.

cytology

Living organisms are divided into two major cellular groups: __ and eukaryotes.

prokaryotes

Prokaryotic DNA is typically __-stranded and circular.

single

Eukaryotic DNA is enclosed in a membrane-bound structure called the __.

nucleus

Specialized membrane-bound structures in eukaryotes are called __.

organelles

Plant cell walls are composed mainly of __.

cellulose

Fungal cell walls are rich in __.

chitin

Bacterial cell walls are primarily made of __.

peptidoglycan

Plant cells have a large __ vacuole and chloroplasts.

central

The substance made of water, proteins, and other molecules inside the membrane is the __.

cytoplasm

The cell membrane is a bilayer of __ molecules.

phospholipid

Movement of molecules down their concentration gradient through the membrane is called __.

diffusion

Transport that requires energy to move substances against their gradient is __ transport.

active

Engulfing liquid droplets by the cell is termed __ ("cell drinking").

pinocytosis

Engulfing large particles or cells is called __ ("cell eating").

phagocytosis

The rigid structure that surrounds many cells and helps maintain shape is the __.

cell wall

According to the theory of __, mitochondria and plastids originated as free-living prokaryotes.

endosymbiosis

The green pigment in chloroplasts that captures solar energy is __.

chlorophyll

Mitochondria are often called the __ of the cell.

powerhouses

Rough endoplasmic reticulum is studded with __.

ribosomes

The __ apparatus modifies, stores, and packages proteins and lipids.

Golgi

Storage organelles in plant cells that help maintain volume are __.

vacuoles

Vesicles filled with digestive enzymes are called __.

lysosomes

Self-replicating organelles that break down peroxide are __.

peroxisomes

During mitosis, spindle fibers originate from the __.

centrosome

The protein network that maintains cell shape and aids movement is the __.

cytoskeleton

DNA wrapped around proteins and visible only when condensed is termed __.

chromatin

Somatic cell division that produces two identical daughter cells is __.

mitosis

Germ cells divide by __ to form gametes with half the chromosome number.

meiosis

Exchange of genetic material between homologous chromosomes during meiosis I is called __.

crossing over

A fertilized egg cell with a complete set of chromosomes is a __.

zygote

Red blood cells transport oxygen using the protein __.

hemoglobin

Sperm cells move using a tail called a __.

flagellum

Root hair cells have an elongated membrane to maximize __ absorption.

water and mineral

Guard cells regulate the opening and closing of __ on plant leaves.

stomata

Cells were first described in 1665 by the scientist __.

Robert Hooke

The first observations of living cells were made by __ van Leeuwenhoek.

Anthony

The statement that all cells arise from pre-existing cells was made by Rudolf __.

Virchow

Electron microscopes can magnify up to about __ times.

one million