Bio Exam 4 Chapter 9

michelleburkee2's version from 2015-11-16 12:32

Section 1

Question Answer
if a protein is made from 30 amino acids, how many nucleotides are needed?90
in eukaryotes, translation is done in the ________ by the _____cytoplasm by the ribosome
what always occurs before cell division starts?DNA replication
daughter cells receive exactly half the genetic information of their parent cells as a result of meiosis
whats a gamete?a sex cell with haploid number of chromosomes
cells reproduce through_______ which usually produces _____cell division which usually produces two daughter cells
Each cell receives what from the parent cell?a complete set of identical DNA and about half of its cytoplasm
DNA is organized in a chromosome
segements of DNAgenes
when a cell divides it does whatit replicates its DNA to make two IDENTICAL copies and gives each daughter cell one of the two copies
why do cells divide? 2 reasonsgrowth and development and sexual or asexual reprodution
is required for asexual and sexual reproductioncell division
from a single parent; offspring is clonal (identical to parent)asexual reproduction
who reproduces through asexual reproductionbacteria
from fusion of gametes from two parents; offspring are a mix of the two parentssexual reproduction

Section 2

Question Answer
what is required for growth and development of an organism?cell division
mitotic cell divisioncell division by eukaryotic cells by which organisms gros or incease in number
differentiatebecoming specialized for specific functions
when can diffrentiation happen?after cell division the daughter cells can diffrentiate
the repeating pattern of divide, grow, and differentiate, then divide again is calledcell cycle
stem cellscan continue to divide for the life of the organism
other cells capable of dividingcells that can divide once or twice to become a specific type of cell (i.e. liver cell)
permanently differentiated cellscells that are fully differentiated and wil never divide again (i.e. neuron)
asexual reproduction traitsfrom a single parent; offspring is clonal
offspring are a mix of the two parentssexual reproduction
variants of the same genesalleles

Section 3

Question Answer
DNA of prokaryotes is cirular
5 stages of prokaryotic cell cycle1.) start of growth phase: circular DNA attatched to plasma membrane 2.)DNA replicated. Now both circular DNA are attatched to plasma membrane in seperate locations 3.) cell increases in size and the duplicated chromosomes are pushed apart 4.) the plasma membrane moves inward seperating DNA 5.) the cell splits--> two identical daughter cells
3 differences between DNA in Eukaryotic chromosomes and prokaryotic chromosomes1.) eukaryotic chromosomes are seperated from the cytoplasm by the nucleus 2.) eukaryotic cells have multiple chromosomes 3.) eukaryotic chromosomes are longer and have more DNA
what two things are chromosomes made out of? (eukaryotes)chromatin (DNA and histone proteins)
Prokaryotic DNAsingle circular piece of DNA
are homologous chromosomes usually identical?No they usually are not
enduring mutations inherited generation after generationalleles
allelesnucleotide changes in genes
homologous chromosomes _________ alleles of genesthe same or different

Section 4

Question Answer
in eukaryotes, what happens to DNA during mitosis?it condenses
open reading frames(a gene) has a translation start and a translation end
locithe coding regions
how many genes per locus?one
telomeresthe ends of chromosomes- for DNA stability
centromere it holds two daughter DNA double helices together after DNA replication and it is the attatchment site for the microtubules that move the chromosome during cell division
protect the DNA from unravelingtelomeres
sister chromatidsduplicated chromosomes (two DNA double helices)
when are they sister chromatids?before DNA replication
independent daughter chromosomes after after DNA replication
independent daughter chromosomes each haveone identical DNA double helix
seperated sister chromatids becomeindependent chromosomes
is there a limit on how many times a cell divides?yes
everytime the cell divides, what happens to the telometers?they get shorter
how do we create chromosomes?chromosomes duplicate then they seperate
chromosomes with the same geneshomologous chromosomes
duplicated chromosomes before seperationsister chromatids
diploidcells with pairs of homologous chromosomes
how many chromosomes do human cells have?46
how many chromosomes do sex cells have?23
22/23 chromosomes are autosomes
23 pair of chromosomessex chromosomes. different in male and female
mitotic cell division =nucleur division and cytoplasmic division
mitosisdivision of the nucleus and DNA
cytokinesisdivision of the cytoplasm
mitotic cell division is what type of reproduction?asexual
3 purposes of miotic cell division1.) makes all the specialized cells of an organism 2.) it allows organisms to maintain, repair, and regernate body parts 3.)it is the mechanism whereby stem cells reproduce

Section 5

Question Answer
sex cells are diploid or haploidhaploid
haploiddo not contain pairs of chromosomes but only single set of chromosomes
______ cells contain half the number of _____ cellshaploid cells contain half the number of diploid cells
how are gametes made? By meoisis or mitosis?by meosis
haploid cells fuse to form a diploid zygote
zygotefertilized egg
eukaryotic cell cycle interphase+mitosis
interphasegrowth and DNA duplication
mitosiseach daughter cell gets 23 pairs of chromosomes and half of the cytoplasm and organelles.
three phases of interphaseG1, S, and G2
most eukaryotic cells spend most of their time ininterphase
part of interphase where get nutrients and growthG1
part of interphase when DNA synthesis (replication)S
part of interphase when completion of cell growth and preperation for mitosisG2
how do stem cell reproduce?through miotic cell divisions
what type of eukaryotic organisms endure miotic cell division?all eukaryotic organisms
in mitosis, each chromosome hastwo sister chromatids attatched at the centromere
the five stages of mitosis in orderprophase, metaphase, anaphase, telophase, and cytokinesis
five major events of prophase:1.) duplicated chromosomes condense 2.)spindle microtubules form 3.)nucleur envelope breaks down 4.)nucleolus dissipates 5.)chromosomes are captured by the spindle microtubules
spindle microtubules capture chromosomes howspindle microtubules from the centrioles at the poles extend out and capture chromosomes at their centromeres
how does not have centrioles?plants and fungi
metaphase:the chromosomes line up along the equator of the cell
anaphase:sister chromatids seperate and are pulled to opposite poles of the cell. The spindle elongates and poles move apart
telophase:a nucleur envelope around each group of chromosomes forms
cytokinesis:the cytoplasm is divided between two daughter cells. in animal cells, microfilaments form a ring around the equator of the cell. Divides the cell in two.

Section 6

Question Answer
what drives the cell cycle?CDKs
kinasesenzymes that add a phosphate group to other proteins. This usually turns the protein on or off
CDKs are only active whenthey bind to other proteins called cyclins
what leads to cyclin synthesis?growth factors
what binds to and activates CDKs?cyclin
what stimulates all aspects of cell cell cycle progression?*CDKs*
what are the three major checkpoints in eukaryotic cell cycle?1.) G1-->S (is DNA ready for replication?) 2.) G2-->mitosis (is DNA replicated ok?) 3.)metaphase-->anaphase(are all chromosomes properly alligned at the metaphase place)
mitosis does not happen in what type of cell?neurons

Section 7

Question Answer
what is the key to sexual reproduction in eukaryotes?meiotic cell division
converts cells from ______ to ________diploid to haploid
meiotic cell division producesgametes (sperm or egg) with haploid number of chromosomes
Each gamete receives _________ chromosome(s) from a pair of homologous chromosomesone
meiosis Iseperates the pairs of homologous chromosomes
meoisis IIseperates the chromotids
after meosis II=4 haploid cells
sex=egg+sperm=zygote=diploid fertilized ell
prior to meiosischromosome replication
what three things cause genetic variability?1.) random segregation of homologous chromosomes 2.) crossing over creates chromosomes with novel combinations of genes 3.)fusion of gametes adds further genetic variability to the offspring