life science 2 nd semester exam review

Life Science Life Science 22ndnd Semester Exam Review Semester Exam Review

Basic ConceptsBasic Concepts

Structure of Ecosystems/Levels Structure of Ecosystems/Levels of Organizationof Organization

• Organism – individual living (biotic) thing• Population – group of organisms, all of one

species, which live in the same place and the same time

• Community – all the populations of different species, same place, same time

• Ecosystem – Populations of plant and animals that interact with each other in a given area and with the abiotic parts (non-living)

• Biosphere – The portion of Earth that supports life

Has Nucleus No Nuclear

Membrane

Ribosomes

and DNA

Cell StructureCell Structure

Cell StructuresCell Structures

•1. Cell wall: rigid layer of nonliving material that surrounds the cells of plants–Made of cellulose–Protects and supports the cells

•2. Cell membrane: Boundary that protects the cell from the environment & controls what comes in and out–All cells have–Like a screen door

3. Nucleus: control center for the 3. Nucleus: control center for the cellcell

4. Ribosomes: grain like 4. Ribosomes: grain like bodies on the ER & in the bodies on the ER & in the

cytoplasmcytoplasm

5.Endoplasmic Reticulum: (called ER) 5.Endoplasmic Reticulum: (called ER) carry proteins and materials within the carry proteins and materials within the

cellcell

6. Golgi Body: receives and 6. Golgi Body: receives and packages proteins from ER and packages proteins from ER and distributes around cell and body distributes around cell and body

(mailroom)(mailroom)

7. Cytoplasm: clear gelatinous 7. Cytoplasm: clear gelatinous fluid inside a cellfluid inside a cell

8. Vacuoles: storage area of the cell8. Vacuoles: storage area of the cellPlant has one large vacuolePlant has one large vacuole

Stores food, waste, & enzymesStores food, waste, & enzymes

9. Mitochondria = powerhouse of the cell; 9. Mitochondria = powerhouse of the cell; where cell energy comes from.where cell energy comes from.

10. Chloroplasts: ONLY IN PLANTS 10. Chloroplasts: ONLY IN PLANTS captures sunlight and produces captures sunlight and produces

food for the cellfood for the cell

11. Flagella = used for 11. Flagella = used for movementmovement

12. Cilia = used for movement; 12. Cilia = used for movement; tiny hair-like structures; found tiny hair-like structures; found

on cells that need to move on cells that need to move mucusmucus

D. Absence of a nuclear D. Absence of a nuclear membranemembrane

B. Viruses require a host cell to B. Viruses require a host cell to reproduce.reproduce.

C. flagellumC. flagellum

B. flagellaB. flagella

Questions they (OGT) has Questions they (OGT) has asked the last 4 years.asked the last 4 years.

D. Place the rabbit in a cage D. Place the rabbit in a cage with a heated floor.with a heated floor.

B.B. D.

EvolutionEvolution

Charles Darwin (1809-1882)1. Natural Selection

a. “Only the strongest survive”

2. Darwin hypothesized that when animals had traits that helped them live, they would pass them on to their offspring.

3. Animals who did not possess these traits died.

Darwin’s ExampleDarwin’s Example

1. Darwin noted the different beak structures of finches depended on the island they came from.

2. Finches who lived on islands plentiful in nuts and berries had different beaks than finches who lived on islands plentiful in insects.

Even though all these birds are finches they developed different beaks

depending on the plentiful food source of specific islands.

Examples of Natural Examples of Natural SelectionSelection

1. Galapagos Iguanasa. Some iguanas have

evolved to eat algae.b. Some iguanas have

developed large claws to help them cling to rock.

c. These iguanas evolved from other iguanas because they need those two traits to survive.

d. The algae eating, long clawed iguanas passed these trait on to their young.

e. Iguanas not having that trait.

Everyday green iguana

Galapagos marine iguana

Other adaptationsOther adaptations

1. Camaflougea. Enables species to

blend in with their surroundings.

Can you find the snake’s head?

2. Mimicry – enables a species to look like other species

What part of the plant is this?It’s not part of the plant at all, it’s an insect.

Darwin HypotheticalDarwin Hypothetical

1. Let’s say there was a new “killer” virus that affected dogs.

2. This flu bug only affected dogs with long hair. So, if a dog had long hair (more than ¾ inch long) it would get the virus and die.

3. In 20 years, will all dogs have long or short hair? WHY?

• All dogs would have short hair because all the long hair dogs have died from the virus. There would only be short haired dogs mating with short hair dogs.

• You could say all dogs with short hair were “naturally selected” to live. The dog species has evolved from having both short and long hair to having only short hair.

1. Populations evolve not individuals.

B. B.

C. Had a higher survival rate C. Had a higher survival rate than light moths in the same than light moths in the same

areaarea

One last thing the OGT might One last thing the OGT might get you on……get you on……

• Jean Baptiste Lamarck (1744-1821)– Came before Darwin– Had some of the same ideas as Darwin – No one ever believed him.– Died in obscurity and poverty.

GeneticsGenetics

1. The dominant trait will always be visible2. Dominant-always masks the recessive;

represented by uppercase letter (T, H, D, R)

3. Recessive-will be masked by dominant; represented by lowercase letter (t, h, d, r)-For a recessive trait to be visible, there must be two (tt, hh, dd, rr)

PedigreesPedigrees

XY XX

Father Mother

Daughter

Son Son

c C C

XXcC XYC XYC

Down Syndrome KaryotypeDown Syndrome Karyotype

Darwin’s BackgroundDarwin’s Background

• Born in England, 1809 

• Studied Medicine at Edinburgh University

• Transferred to Cambridge University

• Studied to be a Minister

Library of Congress, Prints and Photographs Division [reproduction number, e.g., LC-USZ61-104].

Charles DarwinCharles Darwin

• Wrote in 1859Wrote in 1859: “On the Origin of Species by “On the Origin of Species by Means of Natural Selection”Means of Natural Selection”

• Two main points:Two main points:

1.1. Species were not created in their present Species were not created in their present form, but evolved from ancestral species.form, but evolved from ancestral species.

2.2. Proposed a mechanism for evolution:Proposed a mechanism for evolution: NATURAL SELECTIONNATURAL SELECTION

Chapter 15

Darwin’s VoyageDarwin’s Voyage

Section 1 History of Evolutionary Thoughthttp://player.discoveryeducation.com/index.cfm?guidAssetId=394121AC

-2256-43A7-8F70-367D66017CFC&blnFromSearch=1&productcode=US

Example of Natural SelectionExample of Natural Selection

Analogous StructuresAnalogous Structures

• Different structure design, same purpose.

Homologous StructuresHomologous Structures

• Different uses, same design

What is Convergent Evolution?What is Convergent Evolution?

• Different unrelated species demonstrate similar traits in response to environment.

What is divergent Evolution?What is divergent Evolution?

• Common ancestor• Develop different

traits

II. Mendel’s LegacyII. Mendel’s Legacy

A. Observed 7 traits (a genetically determined variant of a characteristic) of Garder Peas

A. Height

B. Flower position

C. Pod color

D. Pod appearance

E. Seed texture

F. Seed color

G. Flower color

XI. Homozygous dominant x XI. Homozygous dominant x Homozygous recessiveHomozygous recessive

• Purple is dominant over white

• PP (purple) x pp (white)

P

P

p p

PP

PP

pp

P P

P P

p

p

p

p

Genotypic ratio = 4:0

Phenotypic ratio = 4 purple : 0 white

• Purple is dominant over white

• PP (purple) x Pp (purple)

P

P

p p

PP

PP

pP

P P

P P

P

P

p

p

Genotypic ratio = 2:2

Phenotypic ratio = 4 purple : 0 white

XII. Homozygous dominant x XII. Homozygous dominant x heterozygousheterozygous

• Purple is dominant over white

• Pp (purple) x Pp (purple)

P

p

PP

p

P

P P

P p

P

p

p

p

Genotypic ratio = 1:3:1

Phenotypic ratio = 3 purple : 1 white

XIII. heterozygous x heterozygousXIII. heterozygous x heterozygous

P

r

PR

r

R

R R

R r

R

r

r

r

Genotypic ratio = 1:3:1

Phenotypic ratio = 1 red: 2 pink: 2 white

XIV. Incomplete dominanceXIV. Incomplete dominance

• In roses (R = red, Rr = pink, rr = white)

XV. Co-DominanceXV. Co-Dominance

• In guinea pigs (B = black, Bb = black and white, bb = white)

c.c. taxonomy.taxonomy.

• The science of classifying living things is called

• a. identification. c. taxonomy.

• b. classification. d. speciation.

c.c. become more similar in become more similar in appearance.appearance.

• As we move through the biological hierarchy from the kingdom to species level, organisms

• a. vary more and more.• b. are less and less related to each other.• c. become more similar in appearance.• d. always are members of the same order.

c.c. QuercusQuercus..

• The organism Quercus phellos is a member of the genus

• a. Plantae. c. Quercus.

• b. phellos. d. Protista.

d.d. toxicodendrontoxicodendron..

• Poison ivy is also known as Rhus toxicodendron. Its species identifier is

• a. poison. c. ivy.

• b. Rhus. d. toxicodendron.

d.d. Acer rubrumAcer rubrum..

• The red maple is also known as Acer rubrum. Its scientific name is

• a. red maple. c. rubrum.

• b. Acer. d. Acer rubrum.

c.c. kingdom, phylum, class, order, kingdom, phylum, class, order, family, genus, species.family, genus, species.

• The correct order of the biological hierarchy from kingdom to species is

• a. kingdom, class, family, order, phylum, genus, species.

• b. kingdom, phylum, order, family, class, genus, species.

• c. kingdom, phylum, class, order, family, genus, species.

• d. kingdom, class, order, phylum, family, genus, species.

b.b. species.species.

• The lowest hierarchy level in biological classification is the

• a. genus. c. family.

• b. species. d. order.

d.d. speciesspecies

• Which of the following is the least inclusive classification group?

• a. class c. phylum

• b. genus d. species

Refer to the illustration above. A branching diagram like the one shown is called a

a. phenetic tree.c. family tree.b. cladogram.d. homology.

b. cladogram.

d.d. the Galápagos Islands.the Galápagos Islands.

• Darwin drew ideas for his theory from observations of organisms on

• a. the Samoan Islands.

• b. Manhattan Island.

• c. the Hawaiian Islands.

• d. the Galápagos Islands.

c.c. because of natural selection.because of natural selection.

• According to Darwin, evolution occurs

• a. only through artificial selection.

• b. during half-life periods of 5,715 years.

• c. because of natural selection.

• d. so rapidly that it can be observed easily.

c.c. the idea that species are the idea that species are permanent and unchanging.permanent and unchanging.

• When Darwin published his first book about evolution, he included all of the following ideas except

• a. the idea that species change slowly over time.

• b. the idea that some organisms reproduce at a greater rate than others.

• c. the idea that species are permanent and unchanging.

• d. the idea that some species become better suited to their environment than others.

d.d. species change over time by species change over time by natural selection.natural selection.

• The major idea that Darwin presented in his book The Origin of Species was that

• a. species change over time and never compete with each other.

• b. animals change, but plants remain the same over time.

• c. species may change in small ways but cannot give rise to new species.

• d. species change over time by natural selection.

b.b. organisms with traits well suited to their environment survive and organisms with traits well suited to their environment survive and reproduce more successfully than organisms less suited to the same reproduce more successfully than organisms less suited to the same

environment.environment.

• Natural selection is the process by which• a. the age of selected fossils is calculated.• b. organisms with traits well suited to their

environment survive and reproduce more successfully than organisms less suited to the same environment.

• c. acquired traits are passed on from one generation to the next.

• d. All of the above

c.c. adaptation.adaptation.

• The process by which a population becomes better suited to its environment is known as

• a. accommodation. c. adaptation.

• b. variation. d. acclimation.

a.a. had a common ancestor.had a common ancestor.

• The species of finches that Darwin observed differed in the shape of their beaks. According to Darwin, all of these species probably

• a. had a common ancestor.• b. had migrated from Africa.• c. had descended from similar birds in

Africa.• d. ate the same diet.

d.d. become increasingly different as each population becomes adapted to its own become increasingly different as each population becomes adapted to its own environment.environment.

• Populations of the same species living in different places

• a. do not vary.• b. always show balancing selection.• c. are genetically identical to each

other.• d. become increasingly different as

each population becomes adapted to its own environment.

b.b. must compete for resources.must compete for resources.

• Since natural resources are limited, all organisms

• a. must migrate to new habitats.

• b. must compete for resources.

• c. display vestigial structures.

• d. have inherited characteristics.

Refer to the illustration above. The bones labeled “X” can be referred to asa. vestigial structures.b. sequential structures.c. homologous structures.d. fossil structures.

c. homologous structures.

a.a. share a common ancestor.share a common ancestor.

• Homologous structures in organisms provide evidence that the organisms

• b. must have lived at different times.

• c. have a skeletal structure.

• d. are now extinct.