Cells

Question 1

The cell was first discovered by * in 1665, One observation was from very thin slices of bottle cork. He discovered a multitude of tiny pores that he named “cells”. This came from the Latin word Cella, meaning ‘a small room’ like monks lived in and also Cellulae, which meant the six sided cell of a honeycomb. However

Answer 1

Robert Hooke

Question 2

• is another scientist who saw these cells soon after Hooke did. He named these “*,” which included protozoa and other unicellular organisms, like bacteria. He also found for the first time the sperm cells of animals and humans. Once discovering these types of cells, Leeuwenhoek saw that the fertilization process requires the sperm cell to enter the egg cell.

Answer 2

Anton van Leeuwenhoek

animalcules

Question 3

In 1839, * suggested that every structural part of a plant was made up of cells or the result of cells. In 1839, * states that along with plants, animals are composed of cells or the product of cells in their structures. From these conclusions about plants and animals, two of the three tenets of cell theory were postulated.

Answer 3

Schleiden

Theodor Schwann

Question 4

In 1855, * added the third tenet to cell theory. In Latin, this tenet states Omnis cellula e cellula “every cell originates from another cell.

Answer 4

Rudolf Virchow

Question 5

• are cells that lack a membrane-bound nucleus, mitochondria or any other membrane-bound organelle. Their genetic material is organized into single circular molecule of DNA concentrated in an area of the cell called nucleoid region.

Answer 5

Prokaryotic cells “before nut/kernel”

Question 6

Prokaryotes are divided into two domains:

Answer 6

archaea and bacteria

Question 7

• are prokaryotes that constitute a domain of single-celled microorganism. They were initially viewed as extremophiles living in harsh environments, such as hot springs and salt lakes, but they have since been found in a broad range of habitats, including soils, oceans, and marshlands. They are also part of the human microbiota, found in the colon, mouth, and skin. Archaea in plankton may be one of the most abundant groups of organisms on the planet. Archaea are a major part of Earth’s life and may play roles in both the carbon cycle and the nitrogen cycle - *

Answer 7

Archaea

Methanogen

Question 8

Archaea
Cell membrane: *
Reproduction: * (binary fission, fragmentation, or budding); horizontal gene transfer

Answer 8

ether-linked lipids, pseudopeptidoglycan

Asexual

Question 9

• , any of a group of microscopic single-celled organisms that live in enormous numbers in almost every environment on Earth, from deep-sea vents to deep below Earth’s surface to the digestive tracts of humans. Most bacteria are harmless and are beneficial ecological agents whose metabolic activities sustain higher=life forms. Some bacteria are * (both benefit from the relationship), where they carry out important fuctions for the host such as nitrogen fixation and cellulose degradation. Other bacteria are * , disease-causing organism. DNA acquired from external sources may also be carried on smaller circular structures called *

Answer 9

Bacteria

symbiotes

pathogens

plasmids

Question 10

Individual bacteria can assume one of three basic shapes: * (coccus), * (bacillus), or * (vibrio, spirillum, or spirochete)

Answer 10

spherical, rodlike, curved

Question 11

cell wall of bacteria

Answer 11

ester-linked peptidoglycan

Question 12

The * forms the outer barrier of the cell. The next layer is the cell membrane (plasma membrane), which is composed of phospholipids. Together, the cell wall and the cell membrane are known as the *.

Answer 12

cell wall, envelope

Question 13

• allow cells to attach to surfaces and to each other.

Answer 13

Pili

Question 14

• provide prokaryotic cells with a way to move, also called motility

Answer 14

Flagella

Question 15

The primary function of the nucleus is the protection, organization , replication and expression of the genetic material. The nucleus is surrounded by the nuclear membrane or envelope, a double membrane that maintains a nuclear environment separate and distinct from the cytoplasm. Nuclear pores in the nuclear
membrane allow for selective two-way exchange of material between the cytoplasm and the nucleus; RNA exits the nucleus through these pores. In the nucleolus is where rRNA is transcribed and the subunits of the ribosomes are assembled.

Answer 15

read

Question 16

The genetic material (DNA) contains coding regions called *. Linear DNA is wound around organizing proteins known as *, and is then further wound into linear strands called * . The complex formed between DNA and proteins is *.

Answer 16

genes, histones, chromosomes, chromatin

Question 17

• , the power plants/house of the cell. They have their own circular DNA, with no histones and nucleusomes, that replicates independently from the eukaryotic cell. Also, they replicate independently through binary fission. In addition to keeping the cell alive by providing energy, the mitochondria are also capable of killing the cell by release of enzymes from the electron transport chain. This release kick-starts a process known as apoptosis, or programmed cell death

Answer 17

Mitochondria

Question 18

The mitochondrion contains two layers: the outer and inner membranes. The outer membrane serves as a barrier between the cytosol and the inner environment of the mitochondrion. The inner membrane, which is thrown into numerous infoldings or invaginations called cristae, contains the molecules and enzymes necessary for the electron transport chain. The cristae are highly convoluted structures that increase the surface area available, the site where ATP is made. The space between the inner and outer membranes is called the intermembrane space; the space inside the inner membrane is called the mitochondrial matrix.

Answer 18

read

Question 19

• (ph 4.8) are membrane-bound structures containing acid hydrolase such as proteases, lipases, nucleases and glycosidases (hydrolytic enzymes that are capable of breaking down every major macromolecule within the cell). They fuse with endocytotic vesicles and digest their contents. Under certain conditions, lysosomes will rupture and release their contents into the cytosol, killing the cell in a process called autolysis. Lysosomes come from the Golgi

Answer 19

Lysosomes

Question 20

The * is a series of interconnected membranes that are actually contiguous with the nuclear envelope. The single membrane of the endoplasmic reticulum is folded into numerous invaginations, creating complex structures with a central lumen.

Answer 20

endoplasmic reticulum (ER)

Question 21

The * is studded with ribosomes, which permit the translation of proteins destined for secretion directly into its lumen.

Answer 21

rough ER “granular” (RER)

Question 22

On the other hand, * lacks ribosomes and is utilized primarily for lipid synthesis (cholesterol, steroids, phospholipids) and the detoxification of certain drugs and poisons (oxidization of foreign substances). The SER also transports proteins from the RER to the Golgi apparatus.

Answer 22

the smooth ER “agranular” (SER)

Question 23

• “site of modification, sorting, and secretion of lipids and proteins”

Answer 23

Golgi Apparatus

Question 24

The Golgi apparatus consists of stacked membrane-bound sacs. Materials from the ER are transferred to the Golgi apparatus in vesicles. Once in the Golgi apparatus, these cellular products may be modified by the addition of various groups, including carbohydrates, phosphates, and sulfates. The Golgi apparatus may also modify cellular products through the introduction of signal sequences, which direct the delivery of the product to a specific cellular location. After modification and sorting in the Golgi apparatus, cellular products are repackaged in vesicles, which are subsequently transferred to the correct cellular location. The end product of the Golgi is a * full of proteins.

Answer 24

vesicle

Question 25

• are vesicles in the cytosol involved in the production and breakdown of hydrogen peroxide. * inactivate toxic substances such as alcohol, regulate oxygen concentration and participate in the synthesis and breakdown of phospholipids.

Answer 25

Peroxisomes

Question 26

The * is a network of filaments that provides structure to the cell and helps it to maintain its shape. In addition, the cytoskeleton provides a conduit for the transport of materials around the cell. There are three components of the cytoskeleton: microfilaments, microtubules, and intermediate filaments.

Answer 26

cytoskeleton

Question 27

Microtubules are long, hollow, cylindrical polymers of tubulin proteins. The major microtubule-organizing center (MTOC) in animal cells is * . Within the centrosomes are the *, a conspicuous pair of structures arranged perpendicular to each other

Answer 27

centrosome, centrioles

Question 28

protein synthesis

Answer 28

ribosomes

Question 29

convert light energy—typically from the Sun—into the sugar glucose, a form of chemical energy, in a process known as photosynthesis

possess a circular chromosome and prokaryote-like ribosomes

Answer 29

Chloroplasts

Question 30

• of a mature plant cell typically takes up most of the room in the cell. The vacuole, a membranous bag, crowds the cytoplasm and organelles to the edges of the cell. The central vacuole stores water, salts, sugars, proteins, and other nutrients. In addition, it stores the blue, red, and purple pigments that give certain flowers their colors. The central vacuole also contains plant wastes that taste bitter to certain insects, thus discouraging the insects from feasting on the plant.

Answer 30

Central vacuole

Question 31

• surrounds and protects the plasma membrane. Its pores enable materials to pass freely into and out of the cell. The strength of the wall also enables a cell to absorb water into the central vacuole and swell without bursting. The resulting pressure in the cells provides plants with rigidity and support for stems, leaves, and flowers. Without sufficient water pressure, the cells collapse and the plant wilts.

Answer 31

Cell wall

Question 32

prokaryotic cell has no * but has ribosomes

Answer 32

mitochondria

Question 33

Steps in cellular respiration

Answer 33

glycolysis - Kreb’s cycle/citric acid cycle - Electron transport chain (ETC)

Question 34

ATP produced
Glycolysis
Kreb’s cycle
ETC

Answer 34

2, 2, 34

Question 35

copies of the same chromosome

Answer 35

sister chromatids

Question 36

chromosomes having the same genes at the same loci but possibly different alleles

Answer 36

homologous chromosomes

Question 37

complete set of chromosomes in a species or in an individual organism

Answer 37

karyotype

Question 38

Mitosis and meiosis
Cell:
Division:
Purpose:
Product:

Answer 38

somatic (body) cells, sex cells (gametes)
equational division, reproductional division
for growth and development, for reproduction
produces diploid (2n) cells, produces haploid (n)

Question 39

Stage of mitosis

Answer 39

Prophase - Metaphase - Anaphase - Telophase

Question 40

Where does crossing over occur?

Answer 40

Prophase

Question 41

is the differentiation of the ovum (egg cell) into a cell competent to further development when fertilized

Answer 41

oogenesis

Question 42

process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis

Answer 42

spermatogenesis

Question 43

central dogma

Answer 43

Replication (DNA - DNA)* DNA [polymerase]
Transcription (DNA - RNA) *RNA [polymerase]
Translation (RNA - protein) {ribosomes}

Question 44

DNA as the genetic material is capable of transmitting biological information from a parent cell to its daughter cells and, in a broader perspective, from one generation to another. The information stored in its base sequence is copied accurately by * .

Answer 44

replication

Question 45

• is a process of faithfully copying a DNA to produce two DNA molecules identical to the parent DNA. These DNA molecules are then passed on to the daughter cells via the chromosomes during cell division.

involve

Answer 45

Replication

DNA polymerase

Question 46

The central dogma of molecular biology consists of three general processes namely: replication (DNA synthesis), transcription (RNA synthesis) and translation (protein synthesis). The transfer of information from cell to cell or from generation to generation is achieved by replication. On the other hand, the transfers of information from the DNA to the proteins involve two processes: * . Generally, all organisms follow this mode of transfer except for some viruses that undergo *

Answer 46

transcription and translation

reverse transcription

Question 47

states that the alleles in a gene pair separate cleanly from each other during meiosis.

Answer 47

Law of Independent Segregation

Question 48

states that the alleles of the different genes separate cleanly from each other and randomly combining during meiosis.

Answer 48

Law of Independent Assortment