bio ch 6+7 test

what is the longest phase of the cell cycle

interphase

what is the first step of the cell cycle

G1

what happens to the cell during G1 phase

the cell increases in volume

what is the second phase of the cell cycle

s phase

what happens to the cell during s phase

DNA replication and copying of chromosomes

what is a holder

where a cell stays before moving to the next phase of the cycle until it has what it needs for cell division

what is an example of a holder

G0

what are two example of cells that never get past g1/g0

brain and cardiac muscle cells

what is the third phase of the cell cycle

g2

what happens in g2 phase

final step of preparation, organalles and DNA are checked

what is the last phase of the cell cycle

mitosis

what is the shortest phase of the cell cycle

mitotic phase

what happens during mitosis phase

cell undergoes division and two identical daughter cells are formed

what is the acronym for mitosis steps

PMAT

during prophase what happens to the nuclear membrane

it starts to break down

during prophase what happens to the centrioles

they begin to move to opposite sides

during prophase what happens to the spindle fibers

they start to appear

during prophase what happens to the chromosomes

they become denser and more visible

during prophase what do the chrosomes look like

the letter x held together by a dot in the middle

what are two chromosomes together called during mitosis

sister chromatids

during prophase what holds the sister chromatids together

centromeres

what make sister chromatids visible under microscropes

their centromeres

during metaphase where are the chromosomes

lined up in the middle of the cell

during metaphase what happens to the spindle fibers

one side attaches to the centromere of the chromatids and the other to the edge of the cell

during anaphase what happens to the chromosomes

the spindle fibers pull the chromosomes apart and bring each to opposite sides of the cell

during telophase of an animal cell what happens

the cytoplasm is pinched by cleavage furrow until the cell splits into two

during telophase of a plant cell what happens

a cell plate forms and splits the cell into two

what does cytokinesis mean

dividing the cytoplasm

after PMAT what happens to the two identical daughter cells

the chromosomes unravel DNA and protein and turn back into chromatin

what is the longest phase in interphase

G1

what is the primary checkpoint in interphase

G1

what is telomerase

an enzyme that replicated DNA

when is telomerase active

in utero and in cancer

what is cancer

uncontrolled cell growth

what does benign mean

non cancerous

what does malignant mean

cancerous and metastasis

what does metastasis mean

has the ability to spread

what is apoptosis

programmed cell death

T/F cancer does not go through apoptosis

True

what is contact inhibition

the ability for cells to divide when they come in contact with each other

T/F tumor cells are constantly repairing and producing telomerase

true

what are proto-oncogenes

controls cell division

what are tumor suppressor genes

regulate cell division and reproduction

T/F asexual reproduction does not lead to offspring identical to parent organism

False

what is different about asexual reproduction

only one cell is needed

what is binary fission

when a single bacteria cell splits itself into two identical daughter cells

how long does it take approx. for each bacteria cell to divide

20 minutes

what is a karytoype

a chart showing the chromosomes of an individual from largest to smallest

what does an odd number of chromosomes mean

down syndrome

T/F the acrosome of sperm contains digestive enzymes

True

how many times does pmat occur in meiosis

twice

what does meiosis produce

gametes/sex cells

what is synapsis

the fusion of chromosome pairs at the start of meiosis

during prophase 1 what happens to the nuclear membrane

it starts to break down

during prophase 1 what happens to the spindle fibers

they start to form

during prophase 1 what happens to the chromosomes

the homologous chromosomes start to pair up

how many pairs of chromosomes as a result of meiosis

23

what is a tetrad

two pairs of chromosomes together

when does crossing over occur in meiosis

prophase 1

what is crossing over

when homologous chromosomes exchange genetic information

during metaphase 1

after the first PMAT in meiosis is it haploid or diploid

haploid

during prophase II what happens to the spindle fibers

they are all over the cell

during metaphase II what happens to the chromosomes

they are in the middle attached to the spindle fibers

during anaphase II what happens to the chromosomes

the pairs are pulled apart to either side of the cell by the spindle fibers

what happens during telophase II

the cleavage furrow starts to pinch

what is left after PMAT II of meiosis

four genetic diverse haploid diploid daughter cells

what is oogenesis

the process in a female body that produces eggs

what are the end products of oogenesis

one big egg cell and three nonviable little polar bodies

what is independent assortment

the possibilities of how chromosomes align them self, combination possibilities of genes

how many possible combinations are there for any given egg or sperm, not including crossing over

64 trillion

T/F eggs contain lots of cytoplasm

True

what is nondisjunction

the failure of chromosomes to pull apart through meiosis I and II

what is the result of nondisjunction

down syndrome, uneven chromsomes

what is turner female syndrome

women only have one x sex chromosome and are non fertile

what is a characteristic of turner female syndrome

underdeveloped external and internal sexual characteristics

what is klinefelter syndrome

males born with one y and two x sex chromosomes

what is a characteristic of klinefelter syndrome

enhanced sexual characteristic development, more like female development

what is the most severe form of down syndrome

trisomic 21

what is trisomic 21

an extra chromosome on karyotype 21

what is gene translocation

part of a chromosome (one gene) relocates to different chromosome

what is gene deletion

when an entire gene is deleted

what is gene duplication

exact copy of the same gene is duplicated

what is p53

a protein that checks the DNA for any mutations and either repairs or induces cell death, apoptosis

where does p53 take place

G1

what are histones

proteins that allow the DNA to be wrapped tightly to form chromosomes

what are chromatin

loose DNA in the nuclear envelope, during interphase, unable to see chromosomes at this point

what is encapsulated cancer

noninvasive, does not spread

what is cytokinesis

splitting of the cytoplasm at the end of telophase

during interphase what is inside of the nuclear envelope

chromatin

what is a genome

the entire DNA 6-8 ft long wrapped around histone proteins

what does the DNA look like in prokaryotic cells

circular

what is the order of asexual reproduction

replication of DNA and then cell division

are proto-oncogenes a positive or negative cell cycle regulator

positive

what is the purpose of mitosis cell division

procreation of somatic cells

what is the purpose of meiosis cell division

recreate reproductive cells

how many and what type of cells are produced from meiosis

23 haploid, 1 cell to 2 identical cells

how many and what type of cells are produced from mitosis

46 diploid, 1 cell to 4 different cells