EXAM 3

Question 1

mendels law of segregation: relation to chromosome movement

Answer 1

-each individual has 2 factors for each trait
-the factors separate during the formation of gametes
-each gamete contains only one factor from each pair of factors
-fertilization gives each new individual two factors for each trait

Question 2

mendels law of independent assortment: related to chromosome movement

Answer 2

each pair of factors separates independently
-all possible combinations of factors can occur in the gametes

Question 3

what is an allele? D vs R

Answer 3

an allele is an alternative form of a gene, they occur at the same locus on homologous chromosomes
-dominant allele will mask the expression of the recessive allele
-recessive will only exert its effect in a homozygote

Question 4

genotype vs phenotype

Answer 4

genotype: alleles the chromosomes carry responsible for the trait (the letters)
phenotype: individual’s actual appearance (effect of letters)

Question 5

patterns of inheritance: G and P OUTCOMES

Answer 5

homozygous: 2 of same allele
heterozygous: 2 different alleles (recessive allele is masked by dominant)
-homo dom= DOMINANT
-hetero= DOMINANT
-homo recess. = RECESSIVE
2 HETEROZYGOUS CROSSED IN MONOHYBRID =
genotype= 1:2:1, phenotype= 3:1
TEST CROSS = unknown genotype crossed with homo recess.

Question 6

autosomal dominant vs autosomal recessive

Answer 6

RECESSIVE: most children who are affected have parents who are not affected
-heterozygotes (Aa) have an unaffected phenotype
-2 parents who are affected will always have children who are affected
-close relatives who reproduce are more likely to have children who are affected
DOMINANT: children who are affected will usually have a parent who is affected
-heterozygotes (Aa) are affected
-2 parents who are affected can produce a child who is NOT affected
-2 parents who are UNaffected will NOT have children we are affected
-both males and females are affected with equal frequency

Question 7

Tay Sacchs

Answer 7

recessive disorder!!
-occurs among jewish people
-lack of enzyme Hex A and subsequent storage of its substrate in lysosomes
-development is slowed down in 4-8 months old causing neurological impairment, psychomotor difficulties, blind, seizures, and paralysis

Question 8

cystic fibrosis

Answer 8

recessive disorder!!
-most lethal in white people lol
-chloride ions fail to pass thru plasma membrane (lack of water causes mucus in bronchial tubes which interferes with lungs and pancreas
-difficulty breathing and digesting

Question 9

sickle cell disease

Answer 9

recessive disorder!!
-red blood cells are irregular caused by abnormal hemoglobin
-clog vessels causing poor circulation, anemia
-hemorrhaging leads to jaundice, pain in abdomen and joints, and damage to internal organs
-prevents malaria tho?

Question 10

huntington disease

Answer 10

dominant disorder!!
-leads to degeneration of brain cells
-caused by mutated copy of huntingtin
-effects in teen years then by 10-15 years death will happen

Question 11

incomplete dominant vs codominance

Answer 11

incomplete: heterozygous has intermediate phenotype between homozygotes (red flower + white flower = pink flower)
codominance: both alleles are expressed in heterozygous (red flower + white flower = red and white flower)

Question 12

polygenic inheritance

Answer 12

trait controlled by 2 or more genes
-dominant alleles are additive
-results in continuous variations of phenotype (skin and height)

Question 13

special characteristics of inheritance for ABO blood types

Answer 13

IA= A anitgen
IB= B antigen
i= neither A or B
-IA and IB are dominant over i
-IA and IB are codominant
BLOOD TYPES
A: IAIA OR IAi
B: IBIB or IBi
AB: IAIB
O: ii

Question 14

environment vs genetic trait

Answer 14

nutrition and temperature can influence genetic trait
ex: height influenced by nutrition
-temp of egg incubation determines sex
-himalayan rabbit produces melanin only at low temp

Question 15

why might scientists determine if a trait is strongly affected by environment

Answer 15

the argument nature vs nurture!!
-identical twins live in different environment and both contain same trait, then its genetics
-behavioral traits are partly heritable
on the other hand, if you have a genetic disorder, changing diet can minimize effect of the disease

Question 16

linked genes

Answer 16

genes inherited together
DO NOT SHOW INDEPENDENT ASSORTMENT because linked alleles are all on one chromosome and are inherited together
-crossing over between non sister chromatids on homo chrom.
-22 autosomes and 1 pair of sex chrom

Question 17

X linked inheritance

Answer 17

male receives X-linked allele from mother’s X chromosome

Question 18

phenotype and genotype predictions based on sex linked traits

Answer 18

A Homozygous man X hetero (carrier) woman will give the sons a 50% chance of being affected and the daughters a 50% chance of being a carrier (but wont be affected)

x-linked recessive = more men than woman affected because recessive alleles on X chrom are always expressed in guys

x-linked dominant = affected males only pass down to daughters who have 100% chance of being affected

Question 19

duchenne muscular distrophy

Answer 19

x-linked recessive!!
-wasting away of muscles, absence of protein
-waddling gait, toe walking, frequent falls, difficulty rising, muscle weakness,
-death by 20, males are rarely fathers
-proteins remains by passing from carrier mom to daughter

Question 20

hemophilia

Answer 20

x-linked recessive!!
-affected persons blood does not clot, bleed internally around joints
-can be stopped by transfusions of blood/plasma
Hemo. A = absence of clotting factor VIII
Hemo. B = absence of clotting factor IX

Question 21

how do chromosomes disorders arise

Answer 21

NONDISJUNCTION!!
failure of homo chrom. or sister chromatids to separate during either mitosis or meiosis, produces cells with abnormal chromosomes

trisomy: extra chromosome
monosomy: one less chromosome

Question 22

down syndrome

Answer 22

autosomal trisomy!!
short stature, eye lid fold, flat face, stubby fingers, large fissured tongue, mental impairment
-happens by nondisjunction of an extra copy of chromosome 21
-chances of having a kid with zds increases at the age of 40

Question 23

turner syndrome

Answer 23

-only 1 chromosome (X)
-short with webbed neck, high palate, small jaw
-congenital heart and kidney defects
-ovarian failure and do not undergo puberty
-NO mental impairment, can live healthy life

Question 24

klinefelter syndrome

Answer 24

male has 2 or more x chromosomes in addition to the Y
-extra X is called Barr body
-testes and prostate gland are underdeveloped
-breasts, large hands and feet, slow to learn, increased chance of lupus and breast cancer

Question 25

poly-x females

Answer 25

more than 2 x chromosomes in females -tall and thin -possibility of menstrual difficulties but most are fertile -more than 3 x chromosomes = intellectual disabilities

Question 26

chromosomal deletion

Answer 26

chromosome loses an end piece due to break

Question 27

chromosomal duplication

Answer 27

chromosome segment occurs more than once

Question 28

chromosomal translocation

Answer 28

movement of one chromosome segment from one chromosome to another extra material from one, missing material fro another (abnormalities)

Question 29

chromosomal inversion

Answer 29

segment of chromosome is turned 180 degrees (opposite)

Question 30

List two observations Darwin made on his voyage that influenced the development of his theory

Answer 30

He visited tropical rainforests and other new habitats where he saw many plants and animals he had never seen before (see Figure below). This impressed him with the great diversity of life -He dug up fossils of gigantic extinct mammals, such as the ground sloth (see Figure below). This was hard evidence that organisms looked very different in the past. It suggested that living things—like Earth’s surface—change over time.

Question 31

Compare and contrast Darwin’s and Lamarck's explanations as to how evolution might happen

Answer 31

Lamarck: acquired characteristics- environment can bring about inherited change ex: giraffe with short necks stretch out their necks to eat leaves, so offspring have longer necks (NO EVIDENCE FOUND FOR THIS LOL) Darwin: natural selection- traits with an advantage are passed down in fertile offspring ex: giraffes with already taller necks survive while shorter necks die making taller gene last longer in giraffe population

Question 32

Describe how theory on natural selections suggests how evolution might work

Answer 32

-individual organisms within a species exhibit variation that can be passed down from generation to the next (variation must be heritable) -organisms compete for available resources -individual organisms within a population differ in terms of reproductive success (more energy = more reproductivity) -organisms become adapted to conditions as the environment changes

Question 33

biological evolution

Answer 33

all the changes that have occurred due to reproductive success in living organisms over geological time

Question 34

fossil evidence for evolution

Answer 34

FOSSIL (remains and traces of past life) -hard body parts most often preserved (bone, teeth, pollen, wood, shells) -majority embedded in sedimentary rock and deposited in layers called strata (younger on top, older on bottom) mold: harded rock with air space cast: silica fills that space

Question 35

five conditions necessary for the allele frequencies in a population to be in Hardy-Weinberg equilibrium.

Answer 35

1. no mutation 2. no genetic drift 3. no gene flow 4. random mating 5. no selection

Question 36

Calculate the genotypic frequencies for a population

Answer 36

just do the math emma

Question 37

five forms of microevolution

Answer 37

mutations: alteration in allele frequency in a population -w/o it there would be no inheritable diversity, are random!! genetic drift: chance events that change allele frequency from one generation to the next -bottle neck effect: catastrophes like hurricanes and volcanoes that kill off a lot of individuals -founder effect: few individuals colonize on an island or new habitat (birds going from forest to the beach) gene flow: movement of alleles between a population -Individuals or their gametes migrate from one population to another and breed in the new population -gene flow increases diversity nonrandom mating: individuals are selective about who their mate is natural selection: fitness (ability of organism to reproduce fertile offspring)

Question 38

each type of microevolution & Define heterozygote advantage and give an example

Answer 38

stabilizing selection: against extreme phenotype for average (tigers cant have long tails bc they will trip, tigers cant have short tails because they will lose balance, so medium works) directional selection: extreme phenotype is favored!!! long tails for lizards make it look like a snake so they stay alive from predators disruptive selection: both extreme phenotypes work but not average (long squirrel tail good for intimidation, short squirrel tail good from running, medium does not do anything heterozygote advantage: only alleles that are expressed are subject to natural selection example: recessive dies due to malaria, hetero isn't affected by any, dominant dies due to sickle cell

Question 39

various forms of species isolating mechanisms

Answer 39

habitat isolation: separated by location (snakes in water can't mate with snakes on land) temporal isolation: breeding at different times or seasons (skunk breeds in fall, another breeds in winter) behavioral isolation: different courtship rituals (bluefoot boobies do a lil dancy dance while masked boobies practically makeout) mechanical isolation: physical incompatibility (penis does not fit vag) gametic isolation: molecular incompatibility of sperm and eggs

Question 40

the processes, including examples, by which speciation can occur.

Answer 40

allopatric speciation: geographical barriers separate a population into 2 groups (dam) sympatric speciation: speciation occurs in same region, but just isolate themselves adaptive radiation: one species becomes many through natural selection -galapagos finches reproduced and ended up in all areas of islands -different beaks due to different food sources

Question 41

how phylogenetics, the theory of evolution, and classification of organisms are interrelated.

Answer 41

phylogenetics: study of evolutionary relatedness of groups of organisms phylogeny: hypothesis of evolutionary relatedness among taxa (group of shared traits) represented by tree

Question 42

biogeographical evidence for evolution

Answer 42

forms evolved into one large locale then spread to accessible regions causing a mix in different plant and animal species continental drift: movement of earths crust through tectonic plates causing the movement of continents also caused mass extinction of certain plants and animals

Question 43

anatomical evidence for evolution

Answer 43

homologous structures: similar in different types of organisms because they descended from the same ancestor analogous structures: similar in function BUT differs in anatomy and was evolved separately (eyes of octopus and eyes of human, same function but we aren't related) transitional structure: a structure that was functional to the ancestor but serves no use now (whales still have a pelvis because at one point they walked on land even tho they dont now) vestigial: one function in one group but no purpose in closely related group (pelvis irrelevant to snakes, we use pelvis for birth and movement)

Question 44

biochemical evidence for evolution

Answer 44

all living organisms contain DNA, ATP, have the same triplet code for 20 amino acids, enzymes,

Question 45

Describe contributions of Leeuwenhoek and Pasteur to the science of microbiology.

Answer 45

Leeuwenhoek: discovered one of the first lenses to view microscopic forms -believe these life forms can evolve from spontaneous matter Pasteur: 1st experiment was boiling sterilized broth and creating microbial air -concluded there was something smaller than bacteria, VIRUSES, created vaccine

Question 46

Explain what is meant by the term microbiota.

Answer 46

typical complement of bacterial species found on the human body unaware of their presence, but have beneficial effects

Question 47

Give examples of beneficial effects of microbes.

Answer 47

bacteria on skin helps crowd out harmful microbes -bacteria in intestines aids in digestion and making vitamin K and B12

Question 48

Distinguish between chemical and biological evolution.

Answer 48

CHEMICAL= early earth, inorganic chemicals (capture energy), small organic molecules (polymerization), polymers BIO= (plasma membrane) protocell, (origin of genetic code) cell, cell goes into to 1st self replication, LUCA which is the common ancestor for all life, extant organisms

Question 49

List and describe the four stages that are thought to have led to the formation of cells.

Answer 49

stage 1: organic monomers -simple organic molecules evolved from inorganic compounds (amino acids, nucleotides) stage 2: organic polymers -monomers joined to make polymers (DNA, RNA, proteins) stage 3: protobionts -polymers enclosed in membrane to form first cell precursor stage 4: living cells -protobionts acquired self replication, and other cell properties

Question 50

Explain the methods and significance of the Miller-Urey experiment.

Answer 50

purpose was to test that amino acids could have derived from natural chemical reactions in young earth -amino acids formed from ammonia, nitrogen, CO2, CO, methane, water, and H2 in earths atmosphere

Question 51

List some of the major characteristics used to distinguish Archaea, Bacteria, and Eukaryotes.

Answer 51

Archaea: genome is single, closed, circular DNA molecule -plasma membrane with a single lipid layer -methionine is at start of protein synthesis -no nucleus or organelles and has histones!! Eukaryotes: has nucleus and organelles, histones and introns, -methionine is at start of protein synthesis Bacteria: lacks nucleus and membrane bound organelles in cytoplasm .2-10 um in size

Question 52

Distinguish between halophiles, thermoacidophiles, and methanogens.

Answer 52

halophiles: salty habitats -isolated from environment such as great salt lake, dead sea thermoacidophile: extremely hot, acidic, aquatic -hot springs, geysers, underwater volcanoes -evolved to function at temperatures at 80C methanogens: use CO2 and hydrogen as energy sources -produce methane -in anaerobic environments like swamps, and intestines of animals (cows, humans)

Question 53

Identify the major structural features of bacteria

Answer 53

flagella: in motile bacteria to help move fimbriae: used to bind to surfaces storage granule: singular chromosome plasmids: accessory rings of DNA that carry out genes

Question 54

Describe bacterial reproduction

Answer 54

reproduce asexually through binary fission (bacterial cell replicates its new genomend divides into 2 daughter cells) can form resistant endospores (protects DNA from environment stress)

Question 55

Describe the three ways bacterial can increase their genetic variation.

Answer 55

conjugation: transfer of genetic material from one cell to another (donor cell passes DNA to recipient through sex plius) transformation: bacterium taking up extraneous genetic material from the environment by dead bacteria transduction: viruses carry bacterial DNA from cell to cell

Question 56

Describe the metabolism and ecological function of Cyanobacteria

Answer 56

cyanobacteria are photoautotrophs (have chlorophyll and do photosynthesis to release oxygen) -symbiotic relationship with lichens (lichens provide place to grow and obtain minerals) -camouflage sloths?

Question 57

Describe diseases caused by Streptococcus pyogenes and Staphylococcus aureus

Answer 57

STREPTOCOCCUS PYOGENES -pharyngitis: strep -impetigo: skin disease -scarlet fever: produces red rash -rheumatic fever: auto immune, causes heart damage, caused by untreated strep throat STAPHYLOCOCCUS AUREUS 20% ppl are carriers skin infections strain resistant to methicillin is MRSA (kills young healthy, has gene for toxins) -tuberculosis: lung infection

Question 58

Describe the different types of food poisoning and list two species that cause them

Answer 58

produces toxins while they are growing in food -vomiting and diarrhea -clostridium botulinum (produces one of the most toxic substances on earth) -beauty? cause infection while growing in intestines -salmonella causes symptoms after several days of growing

Question 59

Describe the function of most antibiotics

Answer 59

inhibit bacteria by interfering with a unique metabolic pathway of bacteria -NOT EXPECTED TO HARM HUMAN CELLS either inhibit protein synthesis by bacteria (erythromycin and tetracyclines) OR inhibit cell wall biosynthesis (penicillins and cephalosporins)

Question 60

Describe the pro's and con's of the popular usage of probiotics

Answer 60

Pro: stops the bacteria from interfering with metabolic pathways (AKA less sick yayyy) Cons: potentially fatal allergic reactions -killing off normal flora (beneficial bacteria) -overgrowth of harmful bacteria in intestines and vagina -strains evolved to be resistant to antibiotics MRSA and tuberculosis have antibiotic resistance

Question 61

Distinguish between viruses and prions

Answer 61

viruses: acellular structures that are parasites -use the host cell's replication machinery (ribosomes and enzymes) -capsid: outer portion made of proteins, surrounded by lipid envelope, spikes for attachment -nucleic acid core (DNA , RNA) -can be spherical, helice, or polyhedron prions: protein infectious particles -causes normal proteins change their shape, -degenerative diseases in nervous system -prions through ingestion of infected tissues

Question 62

List and describe the stages of viral reproduction for a rubella virus

Answer 62

1. attachment: spikes of virus bind to a receptor molecule on host cell (virus hijacks it) 2. entry: viral envelope fuses with host's plasma membrane and rest of virus enters cell -uncoating: genome is freed when cellular enzymes remove the capsid 3. replication: viral enzyme makes complementary copies of the RNA genome 4. biosynthesis: RNA molecules serve as mRNA for the production of more capsid and spike proteins using ribosomes 5. Assembly: capsid forms around copy of viral genome 6. budding: new viruses are released from cell surface (acquires envelope and spikes)

Question 63

Describe antigenic drift and shift.

Answer 63

DRIFT: minor genetic mutations (common cold and flu -mutations lead to modified spike SHIFT: major changes take place on surface antigens as genome are reassorted between 2 flu viruses that infect the same cell (2 viruses combine into 1)

Question 64

List several prions and the species they infect

Answer 64

Bovine spongiform encephalopathy or mad cow disease, chronic waste disease in deer elk moose scrapie: sheep scratch off wool

Question 65

Summarize what is known about the evolution and characteristics of the first eukaryotic cells

Answer 65

first eukaryotic cell arose from prokaryotic cell -mitochondria resulted from nucleated engulfed aerobic bacteria, chloroplasts originated from mitochondria engulfed cyanobacteria ENDOSYMBIOSIS

Question 66

Describe the general characteristics of a protist.

Answer 66

eukaryotes -very diverse multicellular, unicellular have meiosis and sex (universal to eukarya) have mitochondria (universal to eukarya)

Question 67

Describe the ways protists can obtain food and energy

Answer 67

photoautotrophs: aka algae, produce food by photosynthesis heterotrophs: aka protozoans, eat bacteria and other protists heterotrophs: aka parasites, derive nutrition from living host, harmed by interaction mixotrophs: use photosynthesis and heterotrophy

Question 68

Describe the basic characteristics of the protist supergroups

Answer 68

Archaeplastida: land plants, green and red algae Chromalveolata: brown algae, diatoms , ciliates, sporozoans, and water molds Excavata: euglenids, flagellates Amoebozoa: amoeboids, plasmodial and cellular slime molds Opisthokonts: animals, fungi, flagellates

Question 69

List the characteristics of Spirogyra.

Answer 69

Archaeplastida charophyte filamentous green algae (cell has ribbon like chloroplast) sexual reproduction by conjugation(cell wall connect by tube and haploid cells fuse)

Question 70

excavata flagellates

Answer 70

most are heterotrophic protozoans that propel themselves using one or more flagella

Question 71

List the characteristics of Euglena

Answer 71

feeding groove -have flagella -photosynthesis -mixotrophy -eye spot for detecting light intesity

Question 72

List the characters tics of Amoeba and Plasmodial Slime molds

Answer 72

Amoeba – organisms with pseudopodia -feed by phagocytosis Plasmodial Slime Molds -single cell -large and multinucleated -feed on decomposers on dead plant matter -fruiting bodies: spores release amoebae LIFE CYCLE Diploid multinucleate plasmodium. Plasmodium develops many sporangia during unfavorable conditions The spores survive until moist and able to germinate Spores release haploid amoebae Haploid amoebae eat decomposers and reproduce or act as gametes and fuse

Question 73

List the characteristics of the fungi we covered in class.

Answer 73

release enzymes into their environment, digest food outside of body, and absorb digested food -some are parasitic and some are saprophytic decomposers(ecycle inorganic nutrients from environment)

Question 74

Describe the symbiotic relationships of fungi with other organisms including mycorrhizal relationships and lichens

Answer 74

lichens: associations between fungi and cyanobacteria algae -efficient at acquiring nutrients and moisture -poor soil, rocky -primary colonizers bc produce organic material for plants mycorrhizae: relationship with plant roots -allow plants to grow in poor soil -plants give products of photosynthesis for fungi -fungus gives minerals to roots -almost all plants have this relationship

Question 75

diatoms

Answer 75

unicellular algae, glassy cell wall made from silica, freshwater marine

Question 76

brown algae

Answer 76

chromalveolate multicellular algae, brown because pigments, kelp (attached to seafloor), primary producers

Question 77

dinoflagellates

Answer 77

chromalveolate unicellular algae -cause blooms in polluted coastal waters -red rides -bioluminescent ocean

Question 78

ciliates

Answer 78

chromalveolate unicellular protists including heterotrophs -named for their use of cilia to move and sweep food into their mouth

Question 79

hyphae

Answer 79

Body a mass of individual filaments in fungi

Question 80

mycelium

Answer 80

mass of hyphae Hyphae give the mycelium a large surface area to facilitate absorption of nutrients

Question 81

ascomycetes sac fungi

Answer 81

cup like structure for reproduction (ascocarp) truffles, cup fungi, and morels -reproduce by producing chains of asexual spores called conidia (molds) ex: penicillium aspergillus (citric acid) yeasts: unicellular fungi, wine and beer

Question 82

basidiomycetes club fungi

Answer 82

sexual reproduction through basidium (edible part of mushroom is basidiocarp

Question 83

. In which kind of cross could you expect to find ratios of 1:1:1:1 among the offspring

Answer 83

two trait test cross

Question 84

. What genetic disorder is associated with the lack of an enzyme necessary for the normal metabolism of the amino acid phenylalanine?

Answer 84

PKU

Question 85

What are the chances that two individuals with wavy hair (an incomplete trait) will have a curly-haired child? Curly hair and straight hair exhibit incomplete dominance

Answer 85

25%

Question 86

When two or more genes with multiple alleles affect the same trait in an additive fashion, it is termed

Answer 86

polygenic inheritance

Question 87

A color-blind (recessive trait) woman will pass the allele

Answer 87

to all their children

Question 88

Generally, it is not possible to determine whether nondisjunction failed to occur in oogenesis or spermatogenesis. However, it is possible to assert that _____ resulted in nondisjunction

Answer 88

XYY, spermatogenesis

Question 89

All cases of Down syndrome are caused by trisomy of chromosome 21.

Answer 89

false

Question 90

What evidence would NOT be studied by a biogeographer

Answer 90

the genetic makeup of organisms that evolved in separate but similar conditions

Question 91

Which of these conditions is NOT among the requirements of the Hardy-Weinberg equilibrium?

Answer 91

small pop with genetic drift

Question 92

Which of the following kinds of molecules is thought to have been absent from the primitive reducing atmosphere

Answer 92

oxygen

Question 93

10. Which of these is a correct description of a form of horizontal gene transfer in bacteria?

Answer 93

conjugation

Question 94

Which of the following is NOT true about viruses?

Answer 94

They contain nucleic acid, protein, and mitochondria.

Question 95

The first membranes that formed before full cells were likely made of

Answer 95

fatty acids

Question 96

Which features set most of the members of protista apart from the rest of the kingdoms

Answer 96

unicellular and microscopic

Question 97

Which is an example of an alga

Answer 97

diatoms

Question 98

At one time, biologists thought that fungi were merely forms of plants that had lost their chlorophyll and had returned to saprotrophy to gain food. Why is this no longer considered a solid theory?

Answer 98

fungi have cell walls made of chitin

Question 99

Amoebae

Answer 99

have a nucleus, are heterotroph, have pseudopods