Biology 1020: Zanzot Exam 3

the key roles of cell division

the ability of organisms to produce more of their own kind best distinguishes living things from nonliving matter

reproduction of cells, or cell division

What is the continuity of life based on?

one cell reproduces the entire organism

How do unicellular organisms divide?

development from a fertilized cell, growth, repair

multicellular eukaryotes depend on cell division for what?

genetically identical daughter cells

Most cell division results in what?

meiosis

What is the exception to cell division making genetically identical daughter cells?

meiosis

a special type of division that can produce sperm and egg cells

cellular organization of genetic material

all the DNA in a cell constitutes the cell's genome

chromosomes

What are DNA molecules in a cell packaged into?

a single DNA molecule (prokaryote) or a number of DNA molecules (eukaryote)

What can a genome consist of?

chromatin

unpacked, more functional form of DNA

chromosme

condensed, and neatly coiled up to travel to new cells

somatic cells

nonproductive cells (2n)

gametes

reproductive cells; sperm and egg (n)

n=23

Human # of paired chromosomes

chromosome (labeled)

between # of chromosomes and organism's complexity

What is there no correlation between?

the chromosome of DNA for that new cell

When sister chromatids separate to 2 new nuclei, they become what?

mitosis and cyokinesis

What does Eukaryotic cell division consist of?

mitosis

the division of the genetic material in the nucleus

cyotkinesis

the division of the cytoplasm

non-identical daughter cells that have half as many chromosomes as the parent cell

Meiosis yields what?

mitotic (M) phase, interphase, cytokinesis

What does the cell cycle consist of?

mitotic (M) phase

mitosis and cytokinesis

interphase

cell growth and copying of chromosomes in preparation for cell division

90%

About how much of a cell's life is spent in interphase?

G1, S, G2

What are the 3 stages of interphase?

S phase

DNA is replicated

cleavage furrow

cytokinesis in animal cells

cell plate

cytokinesis in plant cells

prokaryotes (bacteria and archaea)

Who perform binary fission?

binary fission

the chromosome replicates (beginning Athens the origin of replication), and the two daughter chromosomes actively move apart

mitosis

What can prokaryotic cells not undergo?

binary fission

Where do people think mitosis evolved from?

certain protists exhibit types of cell division that seem intermediate between binary fission and mitosis

Why do people think mitosis evolved from binary fission?

molecular control system

The eukaryotic cell is regulated by what?

the usual controls of the cell cycle

What do cancer cells escape?

frequency of cell division

What varies with the type of cell?

G1 checkpoint, G2 checkpoint, M checkpoint

What are the three checkpoints of the cell cycle?

the cell cycle control system

the cell cycle appears to be driven by specific chemical signals present in the cytoplasm

experiments in which mammalian cells at different phases of the cell cycle were fused to form a single cell with 2 nuclei

What is evidence from to support the hypothesis of the cell cycle control system?

cyclins and cyclin dependent kinases (CDKs)

What are the two types of regulatory proteins involved in cell cycle control?

rises and falls

The activity of a CDK __________ and _________ with changes in the concentration of its cyclin partner

maturation promoting factor

What does MPF mean?

MPF

a cyclin-CDK complex that triggers a cell's passage past the G2 checkpoint into the M phase

endogenous

cells can receive signals to divide from within the cell

exogenous

cells can also be signaled to divide by chemical factors outside the cell

growth factors

What are released by certain cells and stimulate other cells to divide?

platelet derived growth factor

What does PDGF mean?

PDGF

made by blood cell fragments called platelets

crowded cells will stop dividing

What happens in density-dependent inhibition?

anchorage dependence

in order to divide, cells must be attached to a substratum

check the growth of cells at an optimal density

What do density dependent inhibition and anchorage dependence do?

neither

What type of regulation do cancer cells have?

cancer cells

may not need a growth factor to grow and divide; they make their own growth factor; they may convey a growth factor's signal without the presence of a growth factor; they may have an abnormal cell cycle control system

transformation

By what process is a normal cell converted to a cancerous cell

benign tumor

abnormal cells remain at the original site

malignant tumor

invade surrounding tissues and can metastasize, exporting cancer cells to other parts of the body, where they may form additional tumors

high energy radiation

What can localized tumors be treated why?

genetics

the scientific study of heredity and variation

heredity

the transmission of traits from one generation to the next

variation

demonstrated by differences in appearance that offspring show from parents and siblings

genes

the units of heredity; made up of segments of DNA

gametes

genes are passed to the next generation via ___________

locus

specific location of a gene on a chromosome

mother

Who do you get your mitochondria from?

asexual reproduction

a single individual passes genes to its offspring without the fusion of gametes

clone

sexual reproduction

2 parents give rise to offspring that have unique combinations of genes inherited from the 2 parents

depends on the way you measure

What is the largest organism in the world?

somatic cell

any other cell than gamete (body cell)

23 pairs

How many pairs of chromosomes do somatic cells in humans have?

homologous chromosomes (homologs)

the 2 chromosomes in each pair

length; genes

chromosomes in a homologs pair are the same _________ and carry ________ controlling the same inherited characteristics

karyotype

an ordered display of the pairs of chromosomes from a cell

X and Y

sex chromosomes

human females

XX

human males

XY (heterologs)

autosomes

Any chromosome that is not a sex chromosome

somatic cells

autosomes are NOT

gametes

sex chromosomes are NOT

cells

Chromosomes are NOT

diploid

2 sets of chromosomes (2n)

haploid

a single set of chromosomes (n)

23

What is the haploid number for humans?

22 autosomes and a single sex chromosome

Each set of 23 consists of:

X

In an unfertilized egg (ovum), the sex chromosome is

X or Y

In a sperm cell, the sex chromosome may be either

fertilization

the union of gametes

zygote

What is a fertilized egg called?

from each parent

A zygote has one set of chromosomes from _________

mitosis

Zygote produces somatic cells by ________ and develops into an adult

meiosis and fertilization (and mitosis)

the 3 main types of sexual life cycles differ in the timing of:

diploid to haploid

Meiosis reduces the number of chromosome sets from:

2 sets of cell divisions

Meiosis consists of:

4 daughter cells

What does meiosis result in?

half

The daughter cells in mitosis have ________ as many chromosomes as the parent cell

meiosis I (reductional division)

homologs pair up and separate resulting in 2 haploid daughter cells with replicated chromosomes

meiosis II (equational division)

sister chromatids separate

comparison of mitosis and meiosis

-mitosis conserves the number of chromosome sets, producing cells that are genetically identical to the parent cell
-meiosis reduces the number of chromosomes sets from 2 to 1, producing cells that differ genetically from each other and from the parent cell