Biology Exam 2: Photosynthesis, Mitosis, Meiosis, Genetics

Which products of the light reactions are used in the Calvin cycle

ATP and NADPH

What type of plant has adapted to minimize the cost of photorespiration by incorporation co2 into 4 carbon compounds which is then transported to the bundle sheath for processing

C4 plants

prophase mitosis

Chromosomes condense, nuclear envelope breaks down

At the conclusion of mitosis, each daughter cell has ____.

DNA identical to the parent cell

somatic cells (non reproductive cells) gametes (reproductive cells: sperms and eggs)

- have two sets of chromosomes (2n) -have half as many chromosomes as somatic cells (n)

Progeria

-Autosomal dominant - accelerated aging

chlorophyll a chlorophyll b

-absorbs most blue-violet light and red -only pigment that makes up a reaction center -absorbs most in blue and red -neither a or b absorb in green chlorophyll a to b ratio 6:1 plants in shade have more chlorophyll b

Random Fertilization

-adds to genetic variation because any sperm can fuse with any ovum (unfertilized egg) -fusion of two gametes produces a zygote with any of about 70 trillion diploid combinations

Cystic Fibrosis

-common lethal genetic disease caused by recessive allele -impaired transport of Cl- in lung cells -does not move Cl- outside of the cell -accumulation of mucus -digestive problems

thylakoids

-connected sacs in the chloroplast which compose a third membrane system -may be stacked in columns called grana -location of chlorophyll

heterotrophs

-consumers of the biosphere -obtain their organic material from other organisms -depend on photoautotrophs for food and o2

ABO blood groups: multiple alleles and co dominance

-controlled by one gene -encodes 3 alleles -only two of the many different alleles for each trait

autosomes

-diploid cell has two sets of chromosomes -two chromosomes in each pair are called homologous chromosomes -46 chromosomes in a human somatic cells are two sets of 23 one from mother and one from father -a homologous pair are the same length and shape carry genes controlling same inherited characters -humans haploid number n=23 diploid is 2n=46

family pedigree-mendels principles

-earlobe attachment -tongue rolling -dimples -handedness -freckles -curly-straight hair -hairline shape -PTC tasting -reg-green color blindness

eukaryotic cell cycle is regulated by a molecular control system

-frequency of cell division varies with type of cell -optimal condition bacteria 20 mins embryo cells 8 mins mouse 3 hrs frog 30 min heart and nerve cells do not divide after maturity liver cells retain ability to divide-important for liver transplantation

cyclic cycle electron flow

-generate ATP using proton gradient -does not produce O2 or NADPH -occurs when high levels of NADPH are present -balance ATP/NADPH energy budget -protects PS2 against photinhibition (light induced damage to ps 2, reduction in photosynthesis capacity)

independent assortment of fertilization

-homologous pairs of chromosomes orient randomly at metaphase 1 and of meiosis -in this, each pair of chromosomes sorts maternal and paternal homologs into daughter cells independently of the other pairs -number of combinations possible is 2^n where n is the haploid number -more than 8 million combinations of chromosomes -two gametes never have the same combination of chromosomes

Distribution of Chromosomes

-in prep for cell division, DNA is replicated and the chromosomes condense -each duplicated chromosome has two sister chromatids attached along their lengths by cohesins -centromere: narrow waist of the duplicated chromosome where the two chromatids are most closely attached -kinetochore is the centromere and protein attachment

Dominant Disorders: Huntingtons

-involuntary movement -faulty gene for a protein called huntington -causes degeneration in many regions of the brain and spinal cord especially basal ganglia -is one is a carrier you have 50% chance of getting it -symptoms manifested at middle age=creates family planning problems

nondisjunction

-members of a chromosome pair fail to seperate at anaphase, producing gametes with an incorrect number of chromosomes -ND can occur during meiosis 1 and 2 -more frequently in females (maternal age effect)-prolonged arrest of oocytes in prophase 1=loss of cohesion in meitotic sister chromatids=incorrect MTB-kinetochore attachment and chromosome segregation error -M 1: all abnormal they fail to seperate in the first stage M2: half abnormal half normal

chemiosmosis in chloroplasts and mitochondria

-mitochondria: protons are pumped to the inter membrane space and drive atp synthesis as they diffuse back into the mitochondrial matrix -chloroplasts: proton are pumped into the thylakoid space and drive ATP synthesis as they diffuse back into the stroma

Light Independent/Calvin Cycle

-occurs in the stroma -forms sugar from co2, using ATP and NADPH from light reaction -begins with carbon fixation: incorporating co2 into organic molecules -products= glucose + NADP + ADP

PKU

-phe hydroxylase: enzyme needed to convert essential amino acid -phenylacetate accumulation=progressive intellectual disabilities or mental retardation until puberty -seizures -tremors or jerky hand and leg movements -hyperactivity, stunted growth, eczema -distinct odor in breath, skin, urine -avoid Phe

autotrophs

-producers of the biosphere - produce organic molecules from: CO2, h20, other inorganic molecules and sunlight -sustain themselves without eating anything derived from other organisms -almost all plants are photo-autotrophs

Genetics

-scientific study of heredity -heredity: the transmission of traits from one generation to the next

Many human traits

-show simple inheritance patters -are controlled by single genes on autosomes

Variations on mendels laws

-some patterns of genetic inheritance are not explained by mendels law -incomplete dominance -codominance -multiple alleles -polygenic inheritance -plieotropy

When Meiosis goes Awry

-such mistakes can result in genetic abnormalities that range from mild to fatal

Neurofibromatosis (autosomal dominant)

-tumor disorder -non-cancerous tumors along nervous system -scoliosis -learning disabilities -visual disorders -epilepsy not the same as Proteus syndrome-mutation in neurofibromin

chloroplasts

-two membranes surrounding a dense fluid called the stroma

key to cancer

-understanding control of cell division -hayflick limit: concept-normal cells divide 40-60 times before it cannot divide anymore-programmed cll death cancer cells=uncontrollable growth

Your father is heterozygous for a recessive disorder. You know your mom has two "good" alleles. What is the probability that you will have the disorder?

0%

Trace the path of a single electron through the noncyclic electron pathway by putting the following in order:

1) The electron is released from water and added to the photosystem. 2)The electron is excited in photosystem II. 3)The electron is passed to the plastoquinone pool. 4) A proton gradient is generated by the cytochrome complex as the electron arrives and then departs 5) The electron is excited in photosystem I. 6) The electron is transferred to NADP+.

8 steps to the linear electron flow

1, PS2 chl absorbs sunlight, light energy causes e excitation which is passed from chl molecule to chl molecule. chlorophyll reaction center caused a pair of chlorophyll molecules to become excited, get passed to the primary electron acceptor (pheophytin) 2. the electrons become so energized they leave the PS2 to nearby electron acceptor to the ETC 3. to replace lost electrons, h2o is split by enzymes releasing o2, 2h+, 2 electrons 4. each electron falls down an etc from the primary electron acceptor of PS2 to PS1 5. energy released by the electron fall drives the creation of a proton gradient across the thylakoid membrane, higher conc of h+ in thylakoid space, lower conc of h+ in stroma diffusion of H+ across membrane drives ATP synthesis using ATP synthase 6. in PS1 light energy excites chlorophyll (P700) electrons are energized, escaping PS1 and moving down a second ETC to an electron acceptor 7.each electron fats down an ETC from the primary electron acceptor of PS1 to the protein ferredoxin (Fd) 8. the H+ and electrons are then transferred to NADP+ and reduces it to NADPH, electrons of NADPH available for Calvin cycle -light reactions generate energy by producing: ATP and NADPH

Mendels four observations from the monohybrid cross

1. alternative versions of genes are called alleles 2. organism inherits two alleles, one from each parent homozygous: for that gene if both alleles are identical heterozygous: for that gene if alleles are different 3. one determines the organism's appearance and is called dominant allele and one with no noticeable affect is a recessive allele 4.each organism contains two alleles for each trait and alleles segregate during the formation of gametes: law of segregation -half carry one allele and the other half carries the other allele -fertilization= two alleles for each trait one from each parent

Law of Segregation Law of independent assortment

1. gamete formation, alleles of each gene segregate from each other so each gamete carries only one allele for each gene 2. law of independent assortment: genes for different traits can segregate independently of the other genes during the formation of gametes

Regeneration of RuBP (Calvin Cycle)

1. use 3 ATP to regenerate RuBP

Embryonic development begins with a single egg fertilized by a single sperm forming a zygote. The zygote then undergoes mitosis; how many cells would be present at the conclusion of 4 mitotic divisions?

16

A haploid cell in human has how many chromosomes

23

If a species has 42 pairs of chromosomes, which value represents the number of combinations of maternal and paternal chromosome combinations that will be sorted to the poles?

2^42

The first carbon fixation product in C3 plants is:

3 phosphoglycerate

Reduction (Calvin Cycle)

6ATP invested to make 6 1,3-bisphosphoglycerate 6NADH converts them to six G3P one of these is removed

photosynthesis equation

6CO2 + 6H2O + light energy --> C6H12O6 + 6O2

how many ATP does the Calvin cycle use to make one G3p molecule

9ph

Recessive Disorders

Most human genetic disorders are recessive. (rr) Individuals who have the recessive allele but appear normal are carriers of the disorder (Rr)

If you put chloroplasts in the dark, they can continue to make sugar if provided with

NADPH, ATP, CO2

difference between noncyclic and cyclic

NCP: -formation of ATP and NADPH -electrons flow from H2O o PS2 to PS1 to NADPH -makes O2 from splitting H2o -makes ATP from H+ gradient CP: -use only PS1 -only some ATP is produced -no splitting of water -electrons come only from light harvesting complex

animal cells vs plant cells

a. cleavage of an animal cell b. cell plate formation in a plant cell (TEM)

Lethal Recessive Lethal dominant

aa=affected Aa=carrier AA=normal pku, sickle cell, tay Sachs, cystic aa=normal Aa=affected AA=affected huntingtons, marfans

The molecule of chlorophyll a in photosystem II's reaction center is known as P680 because

absorbs wavelength of 680 nm

genome

all the dna in a cell constitutes the cells -can contain a single dna molecule or a number of them -chromosomes: dna molecules in a cell are packaed into -eukaryotic chromosomes consist of chromatin: a complex of DNA and histones (nucleosomes) that condenses during cell division -drosophilia: 8 human: 46

Sister chromatids are best described as two chromosomes having

an identical DNA sequence

karyotype:

an image that reveals an orderly arrangement of chromosomes -homogolous chromosomes: are matching pairs of chromosomes that can possess different versions of the same genes (alleles) example: flower color

Rules of probability

apply to the inheritance of single gene traits, if parents are known you can establish chances for inheriting a particular genotype Punnett square predicts: probability of a trait happening -four possible combos of gametes -four possible offspring in f2 generation

During which of the following periods does a CAM plant take in atmospheric carbon dioxide for photosynthesis?

at night

Marfan syndrome

autosomal dominant -range of symptoms and progressive -disorder of human connective tissue -defects of heart valves and aorta=cardiovascular problems=early death -affect lungs, eyes, skeleton, dural sac surrounding spinal cord -tall, long limbs, thin fingers -scoliosis -flat feet -crowded teeth -misfolded protein fibrillin-1

Sex influenced traits

autosomal traits that are influenced by sex. If a male has one recessive allele, he will show that trait, but it will take two recessive for the female to show that same trait -example is male pattern baldness

Photosynthetic bacteria

bacteria that produce their own food through photosynthesis -leaves are the major locations of photosynthesis -chloroplasts are found mainly in cells of the mesophyll, interior tissue of the leaf -each mesophyll cell contains 30-40 chloroplasts -co2 enters and o2 exits the leaf through microscopic pores called stomata

why do we see chlorophyll as green

because it reflects green light

cytokinesis

begins during anaphase or telophase and the spindle eventually disassembles

if abnormal cells remain at the original site

benign

Calvin cycle

carbon enters the cycle as CO2 and leaves as a sugar named glyceraldehtse 3 phosphate -c3 plants: use the Calvin cycle for fixing co2 directly from the air -regenerates its starting material (RuBP) after molecules enter and leave the cycle

Calvin cycle has 3 phases

carbon fixation: catalyzed by rubisco, most abundant enzyme on earth reduction: formation of G3P regeneration of the CO2 acceptor RuBP

MPF (maturation-promoting factor)

cdk/cyclin complex that forms from increased cyclin production and when at peak, indicates to cell to continue on from G2 to M phase -phosphorylates proteins during cell division -promotes spindle formation -promotes condensation of chromosomes -contributes to degradation of nuclear envelop, ER and golgi

A somatic cell divides to form two genetically identical daughter cells during mitosis. Prior to mitosis occurring, which of the following must occur?

cell must replicate its DNA

density dependent inhibition

cells divide to fill a gap then stop

Mutations

changes in an organisms DNA -the original source of genetic diveristy -average of 64 new mutations when they occur: -due to instability of purine and pyrimidine bases -errors during DNA replication -exposure to environmental factors e.g. UV light chemical cacinogens

in meiosis

chromosomes duplicate during terphase -sister chromatid cohesion: resulting sister chromatids are closely associated along their lengths -sorted into 4 haploid daughter cells

metaphase mitosis

chromosomes line up across the center of the cell

telephase and cytokinesis

cleavage furrow nucleolus forming -nuclear envelope forming

in photosynthesis

co2 becomes reduced and h20 becomes oxidized

In the human ABO blood typing system, an individual with A and B alleles will express both A and B phenotypes on their red blood cells. This is an example of

codominance

crossing over and synapsis during prophase 1

cohesins: after interphase the sister chromatids are held together by proteins synaptonemal complex: holds the homologs together tightly DNA breaks are repaired, joining DNA from one non sister chromatid to the corresponding segment of another

anaphase

cohesion's (Linking sister chromatids together) are cleaved by an enzyme called separase -shorten by depolymerizing at their kinetochore ends non kinetochore microtubules from opposite poles overlap and push against each other elongating the cell

Family pedigrees

common mistake: dominant traits are not always common wild type traits: typical form as it occurs most often in nature, not necessarily specified by dominant alleles -inbreeding increases chance of offspring that are homozygous for a harmful recessive trait

mitosis

conserves the number of chromosome sets, producing cells that are genetically identical to parent cell (2n)

Problem with photorespiration

consumes o2 and releases co2 without producing ATP or sugar, in photosynthesis co2 is taken in, work against each other

mechanisms contribute to genetic variation

crossing over independent assortment of chromosomes 8 million random fertilization 70 trillion mutations 64/gen natural selection

During the light reactions, there are two possible routes for electron flow

cyclic: involves mainly PS1, produces ATP, no NADPH, no oxygen linear electron flow: the primary pathway, involves both PS 1 and 2, produces ATP, NADPH, and O2 using light energy

About 4% of those of Northern European descent are carriers for ____, an autosomal recessive genetic disorder where a defective membrane transport protein leads to abnormal chloride levels in extracellular fluids and hard to clear mucus.

cystic fibrosis

a testcross is used to

determine if a parent with a dominant trait is heterozygous or homozygous

Meiosis 2 (sister chromatids)

difference is that in anaphase 2 the sister chromatids separate, telophase 2 and cytokinesis makes haploid daughter cells (no crossing over)

menders law of independent assortment

dihybrid cross: mating of paternal varieties differing in two characters -two hypotheses are possible from this -dependent assortment -independent assortment

kinetochore:

disc shaped protein at the centromere for MTB attachment

In humans an extra copy of chromosome 21 typically leads to moderate to severe mental retardation and sterility, as well as a greater likelihood of heart defects and other problems. This disorder is known as ____.

down syndrome

kinetochore fibers

during pro metaphase, some spindle microtubules attach to the kinetochores of chromosomes and begin to move the chromosomes -nonkinetochore microtubules are not connected to centromeres -kinetochores are protein complexes associated with centromeres and MTB attachment sites -at metaphase, the chromosomes are all lined up at the metaphase plate, a plane midway between the spindles two poles

light dependent reaction

electrons are removed from water and passed through PS2 and PS1 and finally to NADP making NADPH -makes ATP

Cyclic electron flow to produce ATP

electrons cycle back from Fd to cytochrome complex and back to the PS1 reaction center -only ps 1 and ATP (called cyclic photophorsphorylation) -no nadph and no oxygen -shifts to this when ATP levels drop and NADPH rises, without sufficient ATP, Calvin cycle drops

photosynthesis is a __ reaction meaning it ---- energy

endergonic, requires

C3 plants problem

excessive loss of water and co2 through stomata on hot days when in hot areas, the rubisco acts as an oxygenate instead of carboxylase -lowers productions of sugars advantage: PR reduces buildup of O2 without opening stromata

Nondisjunction refers to

failure of homologous chromosome pairs or sister chromatids to separate during meiosis.

In a diploid organism, daughter cells resulting from mitosis are haploid.

false

It takes one turn of the Calvin cycle to generate one molecule of glucose.

false

Photophosphorylation is more efficient at producing glucose than photosynthesis.

false

Presence of the maturation promotion factor prevents entry into mitosis.

false

True or false: A carrier of a genetic disease or disorder is generally considered to be affected by the that disease or disorder.

false

asexual reproduction involves the fusion of gamete

false

Calvin cycle (the sugar factory)

for every 3 molecules of Co2 that energy the cycle the net output is 1 G3P G3p is a raw monomer for making glucose, cellulose, starch most of G3p is used to regenerate RuBP 2 molecules of G3p are required to make 1 glucose -needs to make 6 turns to make 1 glucose -uses 18 ATP and 12 NADH to produce 1 glucose

Nature of sunlight

form of electromagnetic energy -travels in rhythmic waves -distance between the crests is a wavelength -wavelength is a type of electromagnetic energy

meiosis results in the generation of

four haploid cells

electromagnetic short to long

gamma to radio waves -visible light is the fraction of the spectrum that our eyes see as different colors -sunlight "consists" of discrete packets of energy called photons -when sunlight shines on a pigment, certain wavelengths are absorbed

Linked genes are

genes that do not sort independently due to their being physically near each other on the same chromosome.

telophase

genetically identical daughter nuclei form at opposite ends of the cell

absorption spectrum

graph plotting a pigments light absorption vs wavelenth -violet and red light are absorbed -action spectrum: profile the relative effectiveness of different wavelengths of radiation in driving a process (photosynthesis)

c4 and CAM plants

have adaptations that allow them to survive in hot and dry areas c4 minimize the cost of photorespiration by incorporating co2 into 4-carbon compounds two distinct types of cells in the leaves: -bundle sheath cells: tightly packed around the veins -mesophyll cells: loosely packed between bundle sheath and leaf surface 4 carbon compounds are exported to bundle sheath cells, within these the 4C compounds release CO2 that is then used In the Calvin cycle CAM: to fix carbon, night they open their stomata, day the co2 is released from organic acids and used in the Calvin cycle

meiosis 1 (homologous chromosomes)

homologous chromosomes separate haploid cells with duplicated chromosomes -phrophase 1: (crossing over) all the things are around the cell, sister chromatids, centrosome with centriole pair, spindle, chiasmata (sites of crossing over), fragments of nuclear envelope, homologous chromosomes. 55x in males, 75x in females -metaphase 1: line up in the middle of the cell, microtubules attached to kinetochore, metaphase plate, centromere with kinetochore -anaphase 1: sister chromatids remain attached, homologous chromosomes separate telophase 1 and cytokinesis: cleavage furrow

sex chromosomes

influence the inheritance of certain traits, any gene located on sex chromosomes is called a sex-linked gene, most sex linked are found on the X chromosome, they exhibit unusual patterns of inheritance ex: color blindness, hemophilia, Duchenne muscular distrophy

Carbon fixation

input of 3 co2 entering one per cycle,

cell cycle control system is regulated by both

internal (cyclin and cyclin dependent kinases) external controls (growth factors) cancer cells manage to escape usual controls on the cell cycle

Which sequence of the cell cycle is correct?

interphase, prophase, prometaphase, metaphase, anaphase, telophase

What is the role of MPF in the cell cycle?

it causes the cell to move past the G2 checkpoint and enter the M phase

The microtubules making up the mitotic spindle attach to specialized structures called _________ that are found in the centromere region of the chromosome.

kinetochore

porphyrin ring

light absorbing head of molecule, magnesium is at the center (CH3 is chlorophyll a ) (CHO is chlorophyll b)

two stages of photosynthesis is

light reactions (photo part) and the Calvin cycle (light independent)

packing ratio

linear dna 1 nucleosome 6x nucleosome around 30 nm fiber 1000x mitotic chromosome 10000x

Which of these is a contradiction of Mendel's law of independent assortment?

linked genes

Linked genes

located close together on a chromosome and tend to be inherited together -Thomas hunt morgan -used fruit fly to determine that some genes were linked based on the inheritance patterns of their traits

sex linked genes are genes that are

located on sex chromosomes

chlorophyll a is the

main photosynthetic pigment -accessory pigments (chlorophyll b, carotenoids): -work in conjunction with chlorophyll a which broadens the spectrum used in photosynthesis -absorb excessive light that chlorophylls alone doesn't give them access to -cartenoids cannot transfer sunlight energy directly to the photosynthetic pathway; they must pass their absorbed energy to chlorphylls

where does non disjunction occur where all daughter cells are abnormal

meiosis 1

meiosis reduces the number of chromosome sets from diploid to haploid

meiosis is preceded by replication of chromosomes -meiosis 1 and meiosis 2 -cell divisions result in four daughter cells rather than 2 -has only ahold as many chromosomes (n) as the parent cell (2n)

metaphase

metaphase plate spindle centrosome at one spindle pole

if move away

metastasis

Which of the following cytoskeletal structures make up the mitotic spindle?

microtubules

Maternal inheritance refers to genes found in You Answered

mitochondria and chloroplasts

cell cycle consists of

mitotic (M) phase (mitosis and cytokinesis) interphase (about 90% of the cell cycle) can be divided into sub-phases -G1 phase (first gap) -S phase (synthesis) -G2 phase (second gap)

mitosis

multicellular eukaryotes depend on mitosis for: -development from a fertilized cell -growth -repair -results in daughter cells with identical genetic information (DNA) as parents -2n (diploid)

Cell death

necrosis: -low oxygen, toxins, ATP depletion -random fragmentation -ingested by phagocytes -inflammation apoptosis: -progammed cell death -chromatin condensation, membrane blabbing, single cell death -ingested by neighboring cells, no inflammation -vitamin D dependent?

early observations

normal cells: -anchorage dependence: in order to divide they must be attached to a substratum -density dependent inhibition check the growth of cells at an optimal density cancer cells: -exhibit neither type of regulation of their division

Recombination occurs

only during prophase I and involves swapping between homologous chromatids.

For most multicellular eukaryotes, including humans, mitochondria are inherited

only from the mother

a female will be blind a male will be color blind if he receives

only if she receives the recessive color blind gene on both Xs recessive color blind gene on one X chromosome

If a cell's DNA becomes damaged by radiation or chemicals, it is unlikely to _________.

pass the G2 checkpoint

Which of these is not a C4 or CAM plant

peas

pigments: light receptors

pigments are substances that absorb visible light -about 10 different kinds of pigments -different absorb different wavelengths

place the following in order of most exterior to most interior

plant cell; chloroplast; stroma; geranium; thylakoid; thylakoid space

Progeria is a genetic condition in some humans that causes

premature aging which typically leads to death in the early teens.

The purpose of the synaptonemal complex is to

prevent chromosome fragments from floating free in the cytosol after DNA breakage for recombination. support homologous chromosomes as they undergo recombination. hold the homologous chromosomes tightly together.

photosynthesis

process that converts solar energy into chemical energy

the purpose of the Calvin cycle is to

produce sugars using CO2 as a carbon cycle

crossing overr

produces recombinant chromosomes which combine dna inherited from each parent 1-3 crossover events occurs per chromosome average 1.2 55.2 crossing over sites per cell

anaphase

pulls cells apart daughter chromosomes non kinetochore fibers

In the following list, pick the one that is NOT a source of genetic variability from meiosis and fertilization.

recombination between sister chromatids

meisosi

reduces the number of chromosome sets from diploid to haploid producing genetically different

An F1 dihybrid cross with alleles that are either dominant or recessive

results in aa 9:3:3:1 phenotypic ratio

Natural Selection

results in the accumulation of genetic variations better adapted to the environment-better competition, survival, and reproduction Darwin origin: -favorable traits cause populations to become adapted to their environment over time -favorable traits increase in frequency over generations

what is the most common enzyme found on Earth and is recycled during Calvin cycle to produce G3P

ribulose

Brachydactyly

shortening of fingers and toes (autosomal dominant)

asexual reproduction

single individual passes all of its genes to its offsprings without the fusion of gametes identical to parents clone is a group of genetically identical individuals from the same parent

which of the following are identical copies of a chromosome

sister chromatids

anaphase mitosis

sister chromatids are drawn to opposite poles of the cell

heart and nerve cells

skip G1 and go to G0

the light reactions convert

solar energy to the chemical energy of ATP and NADPH -light splits h2o into hydrogen and oxygen -release o2 -reduce the electron acceptor NADP+ to NADPH -generate ATP from ADP by photophosphorylation -products: o2 + NADPH + ATP

plants

store excess sugar as starch in structures such as roots, tubers, seeds, and fruits sugar made in chloroplast supplies chemical energy and carbon skeletons to synthesize the organic molecules of cells, photosynthesis produces the o2 in our atmosphere

G. Mendel

studied garden peas because easy to grow, came in readily distinguishable varieties, easily manipulated, self-fertilize -readily available -he was the first to analyze patterns of inheritance -deduced fundamentals of genetics

For unknown genotype

testcross is a mating between an individual of dominant phenotype but unknown genotype -homozygous recessive individual

two types of photosystems

PS 2: functions first, best at absorbing wavelength 680 nm, reaction center chlorophyll a of ps 2 called P680 PS1: best at absorbing at 700 nm, reaction center chlorophyll a of ps1 is called p700

Hybrids

the offspring of two different purebred varieties P generation: parental plants F1 generation: hybrid offspring F2 generation: cross of F1 plants form geneticists distinguish between an organism's physical appearance and its genetic makeup -phenotype: physical appearance genotype: genetic makeup

Which of the following statements are true about apoptosis?

the process of a programmed cell death

fertilization is

the union of gametes, fertilized egg is called a zygote and has one set of chromosomes from each parent, zygote produces somatic cells by mitosis and develops into an adult

The advantage of sexual reproduction over asexual reproduction is

there is a mixing of genetic information into a new combination in the next generation.

an autosome is

a chromosome that is part of a pair that is the same in both males and females.

mitotic spindle

a structure made up of microtubules that control chromosomes movement during mitosis -centrosome: -assembly of spindle microtubules begins in the centrosome in animal cells -replicates during interphase, forming two controls that migrate to opposite ends of the cells during prophase and pro-metaphase -MTOC (microtubule organizing center) structure for which mtb emerge 2 functions: 1. organization of cilia and flagells 2. organization of mitotic and meiotic spindles 2 most important types of MTOC in eukaryotes: a. basal bodies associated with cilia and flagells b. centrosomes associated with spindle formation

which of the following is not true of meiosis

a total of two daughter cells are produced

cyclic electron flow is

though to have evolve before linear electron flow -more atp can be produced without producing NADPH

the light reactions occur in

thylakoid

normal to cancer cell converted by

transformation

An individual's complete set of genes and its alleles is the genotype and the observable physical and functional traits is the phenotype.

true

cancer cells do not exhibit density and dependent growth inhibition

true

plants do photosynthesis and cellular respiration

true

You conduct a test-cross on a hamster species in which the dominant phenotype is a solid color coat (T) and the recessive phenotype is a spotted coat (t). If your test-cross is designed to uncover the genotype of a solid colored hamster (T?), which genotype would you cross to your hamster of unknown genotype?

tt

sexual reproduction

two parents have unique combinations to offsprings

A flower exists in which the dominant trait makes the petals blue (B), while a recessive trait fails to make pigment and the resulting flowers are white (b). You cross a blue flowered plant to a white flowered plant and the phenotypic ratio of the resulting progeny is 2 blue flowers to 2 white flowers. What are the genotypes of the parents?

Bb and bb

co-dominance

Botha re expressed (cow has both red and white hairs)

Which is true of a heterozygous organism?

Each homologous chromosome has a different allele at a given locus

Incomplete dominance plants people

F1 hybrids have an appearance between the phenotypes of the two parents (red tower white flower equals pink flower) hypercholesterolemia: both alleles are expressed, heterozygotes have blood cholesterol levels about 2x normal, homozygotes have about 5x the normal amount of blood cholesterol and may have heart attacks as early as age 2

At what stage of mitosis is there a regulatory checkpoint that detects chromosomal abnormalities?

G2

three important checkpoints are those in the G1, G2, and M phases

INTERNAL FACTORS M checkpoint: cells will not begin anaphase until all chromosomes are properly attached to the spindle at the metaphase plate -ensures it has the correct number of chromosomes EXTERNAL FACTORS -influence cell division include specific growth factors -growth factors are released by certain cells and stimulate other cells to divide -platelet derived growth factor is made by blood cell fragments called platelets - in density dependent inhibition, crowded cells will stop dividing

You are genetic counselor, and a couple comes to you with concerns that if they have a child together it could have cystic fibrosis. Genetic tests reveal that the woman is a carrier for cystic fibrosis but the man is not. Which of the following would be a correct thing to tell them?

No child that they produce should wind up with cystic fibrosis, but each of their offspring will have a 50% chance of being a carrier.

Why is photorespiration more likely in warm weather?

Plants are more likely to dehydrate in warm weather, forcing them to close the stomata to conserve water; this prevents CO2 from entering the leaf.

Which is the most correct statement about the role of photosynthesis in an ecosystem?

Primary consumers rely on primary producers to make light energy available in a usable form.

Which of the following is a dihybrid cross

RRMM x rrmm

Which of the following shows an F1 monohybrid cross?

Rr x Rr

Replication of DNA during cell reproduction occurs during ____. Correct!

S phase

Senescing cells are kept from entering ____ because they cannot ____.

S phase; initiate DNA replication

Choose the most correct statement about the two phases of photosynthesis.

The products of the light-dependent reactions are ATP, NADPH, and O2; the products of the light-independent reactions are ADP, NADP+, and sugar.

for many cells

the G1 checkpoint seems to be the most important -if a cell receives go ahead signal to g1 checkpoint it will usually complete the S, G2, and M phases and divide -if not, it will exit the cycle, switching into a non-dividing state called the G0 phase (heart and nerve cells)

Polygenic inheritance

the addictive effects of two or more genes on a single phenotype

Addition of mitosis-promoting factor (MPF) to germinal cells in the skin arrested in G2 would lead to ________.

the cells entering prophase

Photosynthesis reverses

the direction of electron flow compared to respiration endergonic process: energy boost is provided by light -cellular respiration is an exergonic process

The primary difference between mitosis and meiosis in animals is

the generation of haploid cells from diploid cells. the number of daughter cells that result (2 or 4). the number of times chromosomes align at the metaphase plate. the purpose of generating reproductive cells as opposed to generating somatic cell

The oxygen that is released during photosynthesis comes from which molecules?

water

Photoexcitation

when a pigment absorbs light, one of the pigments electrons gain energy- goes from a ground state to an excited state -excited state is unstable, lose energy in form of heat or light or fluorescence

In humans, sex determination generally depends upon

whether or not the Y chromosome is present

The key difference between incomplete dominance and co dominance is

with incomplete dominance it is possible to detect the expression of a recessive allele; in codominance, both alleles contribute equally to the phenotype.

sex chromosomes

x and y female XX male XY remaining 22 pairs are called autosomes gamete: contains a single set of chromosomes and is haploid

Mendel crossed true-breeding plants having yellow peas with plants having green peas. The resulting plant all had yellow peas. An F1 cross resulted in plants having yellow peas and of the plants having green peas. What does this tell you about the alleles for color?

yellow is the dominant color

R is the dominant allele for a round pea, r is the recessive allele for a wrinkled pea. If you cross plants having round peas with plants having wrinkled peas,

you will be able to determine if the round pea plant is homozygous or heterozygous. you are conducting a test cross.