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Ch. 8, 9, 10/11, 12, 13, 15, 16/19

cell cycle

Gap 1, Synthesis, Gap 2, Mitosis/Cytokinesis

interphase

made up of G1, S, & G2; cell grows & synthesizes RNA, proteins, & other macromolecules
G1: cell enlarges & makes new proteins
S: cell replicates its DNA
G2: cell prepares to divide

G0

stage in cell cycle where cells don't divide, but perform their "assigned" function

restriction point

point of no return where cell commits to a full round of the cell cycle

phases of mitosis

prophase - nuclear membrane breaks down, chromosomes become visible, spindle begins to form; metaphase - sister chromatids still attached, line up; anaphase - sister chromatids separate & are pulled to opposite ends

cytokinesis

splitting of the cytoplasm that divides the cell into two cells after mitosis has occured

plant vs. animal cytokinesis

plant - cell plate forms b/w the dividing cells that becomes the cell wall
animal - cleavage furrow forms in same place that becomes cell membrane

cyclins

proteins that regulate progression through the cell cycle

tumor suppressor genes

genes that inhibit cell growth

proto-oncogenes

genes that promote cell division & initiate it to start

p53

enzyme that detects mismatches in DNA base pairs

purposes of mitosis

growth, replace dead/damaged cells, repair cells

structure of a chromosome

2 sister chromatids, each made with chromatin & containing genes, attached in the middle by a centromere

properties of DNA

-3D shape (double helix)
-monomer = nucleotides
-nucleotides = phosphate, deoxyribose (sugar), and nitrogen base
-bases = adenine (A), thymine (T), guanine (G), and cytosine (C)
-sides of "ladder" made up of phosphate & deoxyribose
-"rungs" made up of nitrogen bases

shape of double helix described in & by:

1953, by James Watson, Francis Crick, and Maurice Wilkins

DNA polymerase

enzyme that catalyzes the formation of new DNA strands

origin of replication

place where enzymes & proteins involved in DNA synthesis bond to regions on chromosomes

mutation

any change in a cell's sequence of DNA

excision repair

removes mutations (DNA repair): enzyme recognizes the mismatch, bonds to DNA, breaks the hydrogen bonds, removes damaged DNA, DNA polymerase fills in correct bases, enzyme fixes the bonds between them

cancer & metastasis

uncontrolled reproduction of cells; benign is noncancerous (tumor), malignant is cancerous;
-metastasis = tumor breaks off & spread throughout the body

3 parts of an RNA nucleotide

nitrogen base (uracil, adenine, guanine, or cytosine), phosphate group, & ribose (sugar)

replication

copying DNA; strand splits apart and complimentary bases are filled in, forming two new strands

transcription

the process of making mRNA (temporary copy) from DNA; takes place in the nucleus of the cell

translation

the process of adding amino acids to the growing chain of amino acids in the order specified by the mRNA; mRNA is fed through the ribosome and tRNA adds the amino acids according to what the mRNA says; takes place inside the ribosome

codons/how many/how many amino acids

a codon is an mRNA triplet, there are 64 but only 20 amino acids; start codon is AUG and stop codons are UAA, UAG, UGA

anticodons

tRNA triplet, bonds to complimetary codon on mRNA

RNA processing

primary transcripts of mRNA are processed - mG (5') cap is added to starting end, poly-A tail is added to opposite end, introns (noncoding stuff) is cut out (aka splicing) and exons (code for proteins) are linked back together by ligase

A site

the site where the charged tRNA sits while it adds its nucleotide to the sequence

P site

the site where the second tRNA bonds to the codon that's "waiting"; the tRNA is "waiting" to reach the A site & add its amino acid to the chain

initiation

the ribosome attaches at a specific site o the mRNA (start codon AUG)

elongation

peptide bonds join each amino acid with the next on the chain

termination

when stop codon reaches the A site, release factor binds to the stop codon in the A site & translation stops

frame shift mutation

sequence "shifts" b/c one nucleotide off, changes into different amino acids and the start/stop codons are at different places or gone altogether

structure of a virus

DNA/RNA coated in protein; have some characteristics of life, but not all

bacteriophage

virus that infects bacteria

lyctic vs lysogenic

--lyctic injects its genetic material into the cell, the genetic material enters the cell's DNA, the cell copies the DNA to RNA and some of it gets made into proteins, cell assembles virus, cell explodes, more viruses are relased
--lysogenic = viral DNA makes a circle & inserts itself into the host DNA, the cell's daughters have that viral DNA, & eventualy the virus becomes active & follows lyctic cycle

fertilization (animal)

union of 2 cells (egg & sperm)

gamete

sex cells (egg & sperm)

zygote

fertilized egg

embryo

widdul baby organism! aww :)

activation

egg's metabolism is turned on after fertilization; it then blocks fertilization by a second sperm & the zygote cytoplasm is rearranged by movements in the cytoskeleton (causes differences among cells when they divide)

differentiation

some genes in a cell are turned off & the rest are expressed, which guides the development of the embryo & forms specific cell types

morphogenesis

beginning of the shape / development of the structure of the organism

blastula

animal embryo after cleavage stage; hollow fluid-filled ball of cells (simplest embryos are solid)

gastrula

formed when the blastula folds in on itself; layered, cup-shape embryonic ball; inner cell mass becomes embryo, embryonic stem cells become placenta

primary germ layers

ectoderm: nails, skin, hair, nervous system
mesodern: heart, blood, bones, muscle, sex organs, notochord (backbone)
endoderm: digestive system lining, lungs, bladder, pancreas

cell specializaton/division of labor

cell specializes to perform a certain function in the body (determined by proteins)

symmetry

bilateral - fish
radial - sea anenome

neural tube

becomes spine, can cause sever defects if it doesn't close properly

metamorphosis

-egg --> larva --> adult
-complete also changes lifestyle (frogs)
-incomplete (most beetles)

segmentation

division of the body into a number of similar sections

homeotic genes

genes that say where to turn on gene & how long to turn it on for (where parts belong)

homeobox

homeotic genes in mammals; all are contained in this, & they turn on the transcription of other genes

blastocyst

human blastula

amnion/chorion

amnion = surrounds embryo
chorion = encloses all other membranes

villi/placenta

villi = fingerlike projections into the lining of the uterus
placenta = chorionic villi + uterine lining; exchanges wastes, nutrients, & oxygen

endosperm

tissue that surrounds the plant embryo and transfers nutrients to it from the mother plant

cotyledons

seeds leaves that carry on photosynthesis until the true leaves are developed

apical meristems

zones in the root & tip of undifferentiated cells (like stem cells, but in plants)

primary vs. secondary growth

primary = growth from the merisems present in embryo
secondary = growth in some older plants where the stem & roots grow horizontally in diameter

plasmid

circle of DNA present in bacteria

recombinant DNA

DNA that was cut from a human gene using restrcition enzymes & then inserted in a bacterial plasmid

genetic engineering in medicine & agriculturally

medicine = creates better, more effective medicines & vaccines
agriculture = creates better crops that are resistant to pesticides & disease

asexual reproduction

a single parent produces offspring that are genetically identical to it; binary fission, budding, fragmentating, mitosis, cloning

haploid

one set of chromosomes

diploid

double set of chromosomes

2n

diploid # for an organism

n

haploid # for an organism

daughter cells

cells resulting from mitosis (2, diploid, identical) or meiosis (4, haploid, different)

somatic cells

body cells; are diploid, reproduce by mitosis

gamete

sex cells; are haploid (male - sperm, female - eggs), reproduce by meiosis

sex chromosomes

determines the sex of offspring; X = female & Y = male, so XX = female & XY = male

meiosis

--Prophase I - homologous chromosmes pair up & cross over
--Metaphase I - tetrads (pairs of homologous chromosomes) line up
--Anaphase I - pairs of homologous chromosomes split up
--Telophase I/cytokinesis: 2 haploid cells form, chromosomes still are w/ sister chromatids
--Prophase II - 2 cells have separated
--Metaphase II - sister chromatids line up
--Anaphase II - sister chromatids separate
--Telophase II & cytokinesis - haploid daughter cells form

meiosis in males vs. females

male - proceeds as normal
female - forms one "big" egg with all of the cytoplasm and two polar bodies that are small cells containing chromosomes that eventually disintigrate

3 ways genetic diversity is generated in meiosis

-crossing over = homologous chromosomes exchange corresponding pieces of DNA
-distributes a random mixture of parent's maternal & paternal DNA to each gamete
-independent assortment =alleles for one characteristic divide up randomly b/w gametes independently of alleles for another characteristic

conjugation (in bacteria)

a tube of cytoplasm connects 2 bacteria and they are temporarily connected to pass DNA through the tube & promote variation

meiosis vs mitosis

in meiosis:
-cell divide twice, but chromosomes aren't duplicated after 1st division
-distributes a random mixture of maternal and paternal DNA to the gametes
-involves 2 nuclear divisions that produce 4 haploid cells

parts of a seed

seed coat - encloses endosperm & embryo
endosperm - gives seed nutrients from the mother plant
embryo - baby plant

parts of a seedling (germinated seed)

-primary root (main root); emerges out of the seed first
-secondary root (little roots that branch out)
-stem (called coleoptile in monocots)

germination

sprouting of the seed - needs favorable temperature, water, & O2; the seed begins to form into an adult plant

dormancy

period of time where the seed dries out and stops growing; cellular respiration slows to an extremely low rate & the seed can remain alive for years

pollination

the transfer of pollen from anther to carpel; the pollen travels to the stigma

fertilization (plants)

1 pollen grain meets with the ova, and one pollen gain meets with the two polar nuclei (forming the endosperm)

dispersal

seeds are spread & carried to different locations by humans, birds/animals, insects, wind, water, etc.

**monocot vs. dicot**

**LOOK IT UP**

parts of a flower

-petals
-female: pistil, ovule, style
-male: anther, filament, stamen

process of fertilization in plants

pollen grains land on style & form a pollen tube through the pistil and into the ovary

angiosperm vs. gymnosperm

angiosperm - flowering plant, seeds protected in flower
gymnosperm - "naked seed", seeds protected in cone (like a pine tree)

internal fertilization

male releases sperm into femal reproductive organ

external fertilization

gametes released into the environment (very inefficient)

menstrual cycle

1) estrogen & progesterone are at low levels, hypothalamus secretes GnRH
2) pituitary releases FSH & LH that act on ovary
3) FSH causes egg to start maturing inside follicle
4) LH & FSH stimulate the release of more E
5) E signals uterus lining to thicken
6) sudden increase in LH causes egg to release
7) follicle becomes corpus luteum & continues releasing E & P that further build up lining of uterus
8) FSH & LH slow down, P & E slow down
9) uterus lining declines

follicle & corpus luteum

follicle = fluid-filled sac where egg matures
corpus luteum = ruptured follicle that releases estrogen & progesterone

HCG

human pregnancy hormone released by placenta; signals the corpus luteum to continue releasing progesterone & estrogen

adrogens & testosterone

androgens - group of male hormones
testosterone - major androgen secreted by testes, controls development of 2ndary sex characteristics

Gergor Mendel

-monk & gardener
-concentrated on 7 traits that didn't "blend" when he studied pea plants

Mendel's principles

-segregation: separation of factors into the gametes; each gamete has one allele for a gene, not 2
-independent assortment: alleles for one characteristic divide into gametes independently of the alleles for another

monohybrid & dihybrid crosses

monohybrid - cross where parents differ in one trait
dihybrid - cross where parents differ in two traits

probability

the chance that an event will occur; # of successes over # of possible outcomes

geonotype

genetic makeup of an organism

phenotype

expression of the genotype; appearance/function; observed trait

dominant

allele that masks the presence of another allele of the same gene in a heterozygous organism

recessive

a trait whose expression is masked in a heterzygous organism

allele

one of the 2 (sometimes more) possible forms of a gene

homozygous

having 2 identical alleles for a given trait

heterozygous

having 2 different alleles for a given trait

P generation

parent generation; parents of the "original" generation in a cross

F1 & F2 generations

1st fillial - 1st generation of hybrid offspring
2nd fillial - 2nd generation of hybrid offspring from the interbreeding of the F1 generation

codominance

both alleles are expressed in heterozygotes (ex: calico cats)

incomplete dominance

the phenotype of a heterozygous organism is intermediate between the parents (ex: pink snapdragon)

multiple alleles

more than 2 alleles for a gene (ex: blood type)

sex-linked trait

carried on the x-chromosome, more often found in males because whatever allele on the the x-chromosome they have is the one that's expressed

monosomy & trisomy

monosomy = only 1 chromosome
trisomy = 3 chromosomes

Klinefelter's syndrome

XXY - tall, sexually underdeveloped males, slight mental disability

Down syndrome

extra 21st chromosome - short, severe mental disability, heart defects

Turner's syndrome

X0 - short, sexually underdeveloped, infertile females

translocation (chromosome mutation)

parts of the chromosomes break off and exchange positions

deletion (chromosome mutation)

large region of the chromosome is deleted

inversion (chromosome mutation)

part of the chromosome is "cut", flipped, and put back into place

addition (chromosome mutation)

part of a chromosome is added to another

Human Genome Project

-study genomes of humans & other organisms
-determine the sequence of about 3 billion base pairs of DNA on 24 different chromosomes
-study how genes function

functional genomics

the study of DNA sequence information to help explain cell functions

microarray

computer analysis of DNA segments using probes, can be used to examine the expression of genes

recombinant DNA technology

restriction enzymes cut out a gene from human DNA, cut a bacterial plasmid open, insert the recombinant DNA into the plasmid, and then the plasmidproduces the DNA (ie insulin)

PCR

polymerase chain reaction - makes many copies of a small sample of DNA

SNP

single nucleotide polymorphism - genetic variations in which alleles differ by only one or a few scattered nucleotides

RFLP analysis

restriction fragment length polymorphism analysis - compares lengths of fragments of DNA after restriction enzymes cut them apart, then are separated by size through electrophoresis

gel electrophoresis

DNA is inserted into the wells of a gel, the gel is placed inside a buffer solution (conducts electricity), DNA moves through holes in gel from negative to positive, short fragments move farther & longer don't go as far

microevolution

a change in the gene pool of a population over generations

macroevolution

evolutionary change on a large scale, including speciation, evolutionary trends, adaptive radiation, & mass extinction

population genetics

the sudy of the genetic of groups of interbreeding individuals

gene pool

all of the genes of a local population of organisms

Hardy-Weinberg model & assumptions

-model of gene pools
-p = dominant, q = recessive: p² + 2pq + q² = 1,
p + q =1
-assumes that: organism is diploid, generations don't overlap, large population with little mutation/ migration, no natural selection, sexual reproduction, & gametes unite at random

modern definiation of evolution

change in population over time

coevolution

the continuous adaptation of different species to each other

malaria & sickel-cell alleles

both high in the same areas b/c the sickle-cell allele protects against malaria

difference b/w theory and a law

theory is explanation supported by evidence that can be revised with new evidence, but law just states something; theory holds more weight b/c it has explanatory power

LaMark

use/disuse, organisms aquire adaptations in their lifetime & then pass them on to offspring

Darwin

natural selection, said that organisms already ahd their genes & that the organisms most adapted to their environment & thus able to leave the most offspring were the "fittest"

differences in amino acids chains of humans & gorillas

caused by a mutation

paleontology

the study of fossils

fossil/ "gaps" in fossil record

the fossilized remains of ancient organisms; impint or cast of the bones; "gaps" are there because very few organisms actually became fossils, & so some species do not have any existing fossils at all

Malthus, Lyell, & Wallace

Malthus - overpopulation, struggle for existance; Darwin wondered if this could apply to humans
Lyell - uniformitarianism
Wallace - same ideas as Darwin, but recognized that Darwin thought of them first

artificial vs. natural selection

artificial selection is controlled by the breeder, natural selection is controlled by nature

homolougous & analogous structures

homologous structures = have same structure in different species (human arm & bat wing)
analogous structures = similar function b/c they share the same purpose/environment

genetics provides evidence for evolution b/c...

-similar amino acid sequences
-DNA / molecular evidence
-similarities in development

isolation mechanisms

-behavioral: premating rituals differ
-geographic: separated by distance or geographic barrier
-seasonal: different times
-genetic: infertile offspring/incompatible

types of selection

-disruptive selection: extremes selected for
-stabilizing selection: middle selected for, curve becomes narrow
-directional selection: one side of the curve is selected for, curve shifts position

graudalism vs. puncutated equilibrium

gradualism: gradual changes over time
punctuated equilibrium: rapid periods of change followed by long periods of stasis

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