Chp 9: The Continuity Of Life

Front 1

Cells reproduce by ________

Back 1

cell division. pg-145

Front 2

In cell division a parent cell gives rise to two _________

Back 2

daughter cells. pg-145

Front 3

In typical cell division, _______

Back 3

each daughter cell receives a complex set of hereditary information, usually identical to the hereditary information of the parent cell, and about half of the cytoplasm. pg-145

Front 4

The genetic information of all living cells is called ________

Back 4

deoxyribosome or DNA. pg-146

Front 5

Deoxyribosme or DNA is contained in one or more

Back 5

chromosomes. pg-146

Front 6

A single molecule of DNA consists of a long chain composed of smaller subunits called

Back 6

nucleotides. pg-146

Front 7

A single nucleotide consists of a

Back 7

phosphate, sugar (deoxyribose), and one of the four bases, adenine(A), Thymine(T), Guanine(G) or Cytosine(C). pg-146

Front 8

The units of inheritance are called ________, and are the segments of DNA ranging from a few hundred to many thousands of nucleotides long.

Back 8

genes. pg-146

Front 9

The structure of DNA

Back 9

(a) A nucleotide consists of a phosphate, a sugar, and one of the four bases - adenine(A), thymine(T), guanine(G), or cytosine(C). A single strand of DNA consists of a long chain of nucleotides held together by bonds between the phosphate of one nucleotide and the sugar of the next. (b) Two DNA strands twist around one another from a double helix. pg-146

Front 10

The familiar form of cell division in the eukaryotic cells, in which each daughter cell is genetically identical to the parent cell, is called ________

Back 10

mitotic cell division. pg-146

Front 11

After cell division, the daughter cells may grow and divide again, or they may _________, becoming specialized for specific functions, such as contraction (muscle cells), fighting infections (white blood cells), or producing digestive enzymes (cells of pancreas, stomach, and intestine).

Back 11

differentiate. pg-146

Front 12

The repeating pattern of divide, grow, and (possibly differentiate), then divide again is called the

Back 12

cell cycle. pg-146

Front 13

Two important characteristics of stem cells are

Back 13

self-renewal and the ability to differentiate into a variety of cell types. pg-146

Front 14

Most of the daughter cells formed by the first few cell division of a fertilized egg, and a few cells in adults, including cells in heart, skin, intestine, brain and bone marrow are

Back 14

stem cells. pg-146

Front 15

Stem cells self-renew because ______________

Back 15

they retain the ability to divide. pg-146

Front 16

Most of the cells in your heart and brain cannot divide because they are

Back 16

permanently differentiated cells. pg-147

Front 17

Sexual reproduction in eukaryotic organisms occurs when offspring are produced by the fusion of

Back 17

gametes(sperm and eggs) from two adults. pg-147

Front 18

Reproduction in which offspring are formed from a single parent, without having a sperm fertilize egg, is called

Back 18

asexual reproduction. pg-147

Front 19

Paramecium(commonly found in pounds), and Hydra, can both

Back 19

reproduce asexually. pg-147

Front 20

Both eukaryotic and prokaryotic cells have life cycles that that include,

Back 20

growth, metabolic activity, DNA replication, and cell division. pg-148

Front 21

What occurs in the prokaryotic cell cycle?

Back 21

The DNA of a prokaryotic cell is contained in a single, circular chromosome.

Prokaryotic chromosomes are not contained in a membrane-bound nucleus.

Cell replicates it's DNA followed by a type of cell division called binary fission ("splitting in two").

(1). During the growth phase of the prokaryotic cell cycle, the DNA is replicated producing two identical chromosomes that become attached to the plasma membrane.

(2). As the cell grows, new plasma membrane is added between the attachment sites of the chromosomes, pushing them apart.

(3). When the cell has approximately double in size, the plasma membrane around the middle of the cell grows inward between the two attachment sites.

(4). Fusion of the plasma membrane along the equator of the cell completes binary fission, producing two daughter cells, each containing one or more chromosomes.

(5). Because DNA replication produces two identical DNA molecules, the two daughter cells are genetically identical to one another and to the parent cell. pg-148

Front 22

The principal features of a eukaryotic chromosome during cell division.

Back 22

(a). Before DNA replication, each chromosome consists of a single DNA double helix. Genes are segments of DNA, usually hundreds to thousands of nucleotides in length. Then ends of chromosomes are protected by telomeres.

(b). The two sister chromatids of duplicated chromosome and are held together by the centromere.

(c). The sister chromatids separate during cell division to become two independent, genetically identical chromosomes. pg-150

Front 23

At the end of DNA replication, a ___________ consists of two identical DNA double helices, now called sister ___________.

Back 23

duplicated chromosomes, chromatids pg-150

Front 24

Homologous chromosomes, or homologues are __________

Back 24

chromosomes that contain the same genes. pg-150

Front 25

Cells with pairs of homologous chromosomes are called

Back 25

diploid. pg-150

Front 26

The changes in the sequence of nucleotides in DNA are called _________, and will make one homologue be a little different genetically, than its pair.

Back 26

mutations. pg-151

Front 27

A typical human cell has _____ pairs of chromosomes, for a total of _____.

Back 27

23, 46 pg-151

Front 28

Chromosomes which have similar appearance, similar(but probably not identical) DNA sequences, and are paired in diploid cells of both sexes are called _________.

Back 28

autosomes. pg-151

Front 29

The cell also has two __________: either two X chromosomes(in females) or an X and a Y chromosome(in males).

Back 29

sex chromosomes. pg-151

Front 30

Cells that contain only one of each type of chromosome are called ______, and contain one each of the 22 autosomes, plus either an X or Y sex chromosome, for a total of 23 chromosomes.

Back 30

haploid. pg-151

Front 31

The eukaryotic cell cycle is usually divided into two major phases:

Back 31

interphase and (mitotic)cell division. pg-151

Front 32

During ______ the cell acquires nutrients from it's environment, grows, and duplicates its chromosome.

Back 32

interphase. pg-151/152

Front 33

Interphase contains three subphases:

Back 33

G1, (the first gap in DNA synthesis and the first growth phase), S (DNA synthesis), and G2 (the second gap in DNA synthesis and the second growth phase). pg-152

Front 34

Mitotic and Meiotic are

Back 34

two types of cell division in eukaryotic cells. pg-152

Front 35

1._________ cell division consists of nuclear division called (2._________) followed by cytoplasmic division called (3.__________).

It takes place in all types of eukaryotic organisms.

It is the mechanism of asexual reproduction in eukaryotic cells.

It allows organism to maintain its tissue.

It is the mechanism whereby stem cell reproduce.

Back 35

1.Mitotic
2.Mitosis
3.Cytokinesis
pg-152

Front 36

1.______ cell division is a prerequisite for sexual reproduction in all eukaryotic organisms.

In animals, it occurs only in ovaries and testes.

It process involves a specialized nuclear division called 2.________ and two rounds of cytokinesis to produce four daughter cells that can become gametes (eggs and sperm).

Back 36

1.Meiotic
2.Meiosis
pg-152

Front 37

1._______ is the first phase of mitosis. During this phase three major events occur: (1). _____________, (2). ___________, and (3). _____________.

Back 37

1.prophase

1. The duplicated chromosomes condense, 2. the spindle microtubules form, and 3. the chromosomes are captured by the spindle microtubules. pg-153

Front 38

Growth factors stimulate cell division.

Back 38

Progress through the cell cycle is under overall controll of cyclin and cyclin-dependent kinases(Cdks). In most cases, growth factors stimulate synthesis of cyclin proteins, which activate Cdks, starting a cascade of events that lead to DNA replication and cell division. pg-158

Front 39

Progression through the cell cycle is regulated primarily by two interacting processes:

Back 39

(1). production of, and responses to, growth factors that generally speed up the cell cycle; and (2). intracellular checkpoints that stop the cell if problems such as mutation in DNA or misalignment of chromosomes have occurred.

Most cancers develop because one or both of these processes goes awry. pg-160

Front 40

Any gene whose protein product tends to promote mitotic cell division is called ___________.

It is also the gene for growth factors, growth factor receptors, and some of the cyclins and Cdks are __________.

It is also essential to the normal control of the cell cycle.

Back 40

proto-oncogene. pg-160

Front 41

Meiosis (Greek word meaning "diminish")

Back 41

reduces the number of chromosomes in a diploid cell by half. pg-162

Front 42

During Meiosis

Back 42

the cell undergoes one round of DNA replication followed by two nuclear divisions.

One round of DNA replication produces two chromatids in each duplicated chromosome.

pg-162

Front 43

Meiosis halves the number of chromosomes

Back 43

(a). Both members of a pair of homologous chromosomes are replicated prior to meiosis. (b). During meiosis I, each daughter cell receives one member of each pair of homologues. (c). During meiosis II, sister chromosomes, and each daughter cell receives one of three chromosomes. pg-163

Front 44

Meiotic cell division is essential for sexual reproduction.

Back 44

In sexual reproduction specialized reproductive cells undergo meiosis to produce haploid cells. In animals, these cells become gametes (sperm and eggs). When an egg is fertilized by a sperm, the resulting fertilized egg, or zygote, is one again diploid. pg-162

Front 45

Haploid life cycle

Back 45

meiosis usually occurs soon after fertilization.

Most fungi and unicellular algae spend most of their time in the haploid life cycle.

pg-167

Front 46

Diploid life cycle

Back 46

meiosis usually occurs just before fertilization.

Virtually the entire animal life cycle is spent in diploid life cycle.

pg-167

Front 47

Alternation of generations life cycle (plants)

Back 47

meiosis occurs at the transition between diploid and haploid. pg-167