Test Review

18. How many traits did Mendel assume one gene coded for?

1

What are the three parts of the Cell Theory and who contributed to it?

1. Cells are basic unit of life, 2. All living organisms are made of cells, 3. All cells come from pre-existing cells. Scientists contributing to this theory are Hooke, Schleiden, Schwann, Virchow & Van Leuwenhoek

7. (1.4) In a certain plant population, red flowers (R) are dominant to yellow flowers (r). If there are 50 plants, 10 homozygous dominant, 35 heterozygous, and 5 homozygous recessive, what are the allele frequencies in that population?

10 RR 20 R 35 Rr 35 R and 35 r 5 rr 10 r. Total: 55 R and 45 r, 100 alleles available so 55% R and 45% r

24. What is a dihybrid cross?

A cross between 2 individuals that are both heterozygous for both traits in question (2 factor cross). A dihybird cross is a good way to show independent assortment of chromosomes.

22. What is a monohybrid cross?

A cross between 2 individuals that both have a heterozygous genotype for the trait in question (one factor cross)

17. How many alleles did Mendel assume were possible for any given gene?

2

23. Know how to do monohybrid crosses.

23. Know how to do monohybrid crosses.

25. Know how to do dihybrid crosses.

25. Know how to do dihybrid crosses.

27. Know how to do a test cross.

27. Know how to do a test cross.

33. Know how to do crosses for linked genes (including sex-linked), incomplete dominance and codominance.

33. Know how to do crosses for linked genes (including sex-linked), incomplete dominance and codominance.

3. How many cells result from meiosis? What are these cells?

4 Gametes

• Species

A group of organisms that can interbreed and produce fertile offspring (A lion and a puma are two species so cannot mate to form fertile offspring)

26. What are the phenotypic results of any simple Mendelian dihybrid cross?

9-3-3-1

Lysosome

Contains digestive enzymes, found in eukaryotes.

• Discrete trait

A trait that does not have a range of phenotypes (You can either roll your tongue or you can't - no in between)

• Polygenetic trait

A trait that is affected by more than one gene so there is a wide range of phenotypes (skin tone)

28. Know how to determine which gametes can be formed by an organism given the alleles of that organism (assuming the alleles assort independently)

AaBb- AB Ab aB ab

7. What are multiple forms of a gene called? How many forms of each gene does a regular human body cell have? Where did these copies come from?

Alleles 2 1 allele from each parent for any given gene.

19. What does the law of segregation describe?

Alleles of a gene pair will separate during meiosis.

Centrioles

Animal cells, functions in cell division.

How might this affect the offspring that come from a gamete?

At fertilization, the zygote may have too much or not enough genetic info leading to disorders such as Down's Syndrome

Which organisms are prokaryotes?

Bacteria

Flagella

Bacteria, sperm cells in eukaryotes, movement.

6. (1.2) Summarize how the change in the Peppered Moth species, in England, is an example of natural selection.

Before the industrial revolution, moths that were light colored blended in well to trees and were not eaten. After the revolution, pollution gathered on trees and made them dark so the light moths were eaten. Thus, the light moths were unable to reproduce and those genes did not get passed on. Only darker moths blended in well enough to hide from predators and have reproductive success.

What effect would this have on the gametes?

Causes them to have too much or too little genetic info

What organelles are unique to plant cells?

Cell Wall, chloroplast, large central vacuole

What do prokaryotes and eukaryotes have in common?

Cell membrane, ribosomes, cytoplasm, DNA

Cytoskeleton

Cell transport system. Helps maintain cell shape. Helps anchor the organelles in the cytoplasm. Also found in prokaryotes.

Identify the levels of organization from the cell to the organism.

Cell-tissue-organ-organ system-organism.

What is cell specialization?

Cells in a multicellular organism are specialized to carry out different functions. They are equipped with the certain organelles to help them carry out their function.

Explain the absence of organelles in some specialized cells.

Cells only have the organelles they need to carry out their function.

9. What are mutations?

Change in the sequence of bases in DNA.

• Julian Huxley

Combined the works of Darwin and Mendel to define the modern theory of evolution

Which type do we use in class?

Compound Light

Name two types of microscopes.

Compound Light & Electron

• Gregor Mendel

Determined laws of inheritance

Name the parts of the microscope like the part responsible for providing adequate light.

Diaphragm.

Which type provides a better view of extremely small objects/specimen?

Electron TEM (look inside cells) and SEM (3 D Image)

Endoplasmic Reticulum

Eukaryotes only. Holds ribosomes (RER) and synthesizes lipids and detoxifiying enzymes.

5. What is crossing over?

Exchange of genetic information between homologous pairs of chromosomes (tetrads)

Name the objective lenses and list their magnification.

Scanning-4X Low-10X High-40X.

Which objective lens provides the greatest depth of field?

Scanning.

10. What is nondisjunction?

Failure of chromosomes to separate during meiosis.

Cytoplasm

Found in all cells. Jelly like substance where all the organelles are found.

Cell membrane (what is it made Of)

Found in all cells. Phospholipid bi-layer with transport protein embedded in it. Separates interior of cell from environment. Is selectively permeable.

Cilia

Found in bacteria, some unicellular protists. Function in movement.

Cell Wall

Found in plant cell, made of strong cellulose fibers, helps maintain rigidity.

Golgi Apparatus

Found only in eukaryotes, packaging center of cell. Vesicles break off and form lysosomes.

Nucleus (chromatin, chromosome, nucleolus, nuclear membrane and nuclear pores)

Found only in eukaryotes. Contains genetic information (DNA & RNA). Nucleolus is site of ribosome formation. Chromatin is made of DNA & Proteins. Nucleus is surrounded by semi permeable nuclear envelope or membrane with pores in it.

13. What are Mendel's "factors"? What is the difference between a gene and a trait?

Genes Genes are segments of DNA that code for traits (phenotypic expression of those genes)

4. (1.1) What is the difference between and organism's genotype and phenotype?

Genotype - an organism's DNA, Phenotype - the expressed genes (physical attributes of the organism)

• Population

Group of organisms of the same species that occupy the same place at the same time (All of the catfish in a pond)

4. Each daughter cell has how many chromosomes compared to the parent cell? What is the term used to explain this?

Half, Haploid

Perixosome

Helps detoxify cell from toxic substances the cell produces, found in eukaryotes.

• Evolution

Hereditary changes in groups of living organisms over time

20. What does the law of independent assortment describe?

Homologous chromosomes will line up independently of each other (in a random manner) during meiosis.

11. What information can a karyotype tell you?

If nondisjunction has occurred.

1. When does it happen? Why is it necessary?

In human males it occurs throughout life, females before they are born. Meiosis provides a means of reducing chromosome number in diploid cells to haploid thus allowing the number to be restored to diploid at fertilization.

31. What are the exceptions to Mendel's principal of dominance that we learned in class? Be able to explain how they are different.

Incomplete dominance (intermediate appearance) , co-dominance (expression of both versions of the gene), multiple alleles (more than 2 alleles for a trait), sex-linked genes (found mostly on X chromosome)

29. Be able to interpret a Chi-Square calculation for a genetic experiment.

Is the difference in observed vs expected results significant enough to suggest something other than chance caused the difference?

How do you avoid air bubbles when preparing a wet mount slide? How do you get "rid of" an air bubble?

Lay it at angle, gently tap it.

12. How do crossing over, mutations, independent assortment and random fertilization determine the reproductive success of an organism?

Leads to much more genetic variation within a species of organisms. Organisms with advantageous expressions of genes needed to survive and mature will pass those genes to offspring and are said to have reproductive success.

• How did you know which (dark or light) insects were sensitive to the pesticide?

Light insects gradually disappeared as generations went on, suggesting they didn't live to pass on those genes

32. What are the exceptions to Mendel's principal of independent assortment that we learned in class? Be able to explain how they are different.

Linked genes. Sometimes certain genes tend to "travel" together during meiosis because they are in close proximity to each other on the same chromosome.

What organelles are unique to animal cells?

Lysosomes, centrioles.

What are the characteristics of living things?

Made of cells, displays organization, grows and develops, reproduces, responds to stimuli, requires energy, maintains homeostasis.

What structures do eukaryotes have that prokaryotes do not have?

Membrane-bound organelles, nucleus

34. What is meant by the phrase "multiple alleles"? How is this an exception to Mendel's ideas? Provide an example from class.

Mendel thought there were 2 alleles for a trait. Some traits have more than 2 alleles. ABO blood types, rabbit color.

What does the Endosymbiotic theory state?

Mitochondria & Chloroplasts in eukaryotic cells were once free-living prokaryotic cells.

What evidence exists to support the Endosymbiotic theory?

Mitochondria & Chloroplasts share similarities with prokaryotic cells. They include ribosome size, same kind of DNA, same replication, same size. Also double membrane suggest endocytosis

8. Know the differences between mitosis and meiosis.

Mitosis occurs in somatic cells and diploid cells produce 2 daughter cells that are not only also diploid, but clones as well. Meiosis occurs in gamete-producing cells (germ line). The products are 4 daughter cells that are genetically different from each other and the parent cell (due to crossing over and independent assortment)

• Charles Darwin

Natural Selection

2. Do organisms that reproduce asexually, like bacteria, go through meiosis? Why or why not?

No Because only 1 parent is involved, the daughter cells produced here are clones unless there is mutation.

15. Can you do a Punnett Square for an organism that reproduces asexually?

No, there is only 1 parent

1.4 & 1.5) Use the following data from a scientist's experiment to calculate the allele frequencies of the original population and population after 10 years.

ORIGINAL 27 dominant, 21 recessive Total 48 56% dominant 44% recessive 10 YEARS LATER 22 dominant, 14 recessive Total 36 61% dominant, 39% recessive

21. What is the difference between a one factor cross and a two factor cross?

One factor cross involves 1 trait whereas a 2 factor cross involves 2 traits.

30. What is the difference between the "P generation", the "F1 Generation" and "F2 Generation"?

P is true breeding. F1 are offspring of P and F2 are grandchildren of P.

• Why was there a change in the number of dominant versus recessive individuals over the course of 10 years? (Why was the dominant allele selected for in this example?)

Perhaps the dominant phenotype allowed the organism to survive an environmental change such as a harsh winter or a new predator

• Thoroughly, explain how this is an example of natural selection.

Pesticide resistant insects were able to survive the pesticide and live to pass on their genes to the next generation. As a result, the population changed over time to show the pesticide resistant phenotype.

• Does natural selection (evolution) act on an organism's genotype or phenotype? WHY?

Phenotype because the phenotype actually interacts with the environment to determine reproductive success. Meanwhile, several genotypes could have the same impact on reproductive success (ex, Heterozygous and homozygous dominant)

Compare and contrast plant and animal cells?

Plant cell can make own food.

Chloroplast

Plant cells site of photosynthesis

Which organisms are Eukaryotes?

Plant, Animals, Fungi, Protists

How is that different from pleiotropy?

Pleiotopy is when expression of 1 genes indirectly affects many more phenotypes

14. What do Punnett Squares show?

Possible genotypic and phenotypic outcomes of a cross between two parents

Mitochondrion

Power house of cell only found in eukaryotes.

Provide a timeline to the general appearance of prokaryotes, eukaryotes and multi-cellular organisms in the fossil record.

Prokaryotes-Photosynthetic Prokaryotes-Eukaryotes-Multicellular Eukaryotes.

6. What is independent assortment?

Random assortment of chromosomes during meiosis. They can arrange themselves in a different order each time.

Describe contribution of the following scientists:

Robert Hooke: first to observes cells Schleiden: all plants made of cells Schwann: all animals made of cells

Which objective lens provides the greatest field of view?

Scanning

Calculate total magnification for each objective lens.

Scanning-40X Low-100X High 400X.

Ribosome

Site of protein synthesis, both pro and eukaryotes.

Vacuole

Small in animal cells, large central vacuole in plant cells helps it maintain shape and storage of materials

16. What is the principal of dominance?

Some versions of a gene (dominant) mask or cover up the expression of another version of the gene (reccessive)

• Natural selection

The idea that organisms with favorable traits will survive to pass those traits on to the next generation thereby changing the species over time

35. What are polygenic traits?

Trait determined by more than 1 gene.

xplain the role of proteins in the organization and shape of the cell (ie: cytoskeleton, transport proteins). Describe the path of a protein in a cell.

Transport proteins found in cell membrane help transport substances into and out of cell. Protein is made by ribosome at RER, then carried by vesicle to golgi, then vesicle out of cell or somewhere else in cell.

• Has evolution occurred over the course of 10 years? How do you know?

Yes because the population has changed over time to show more of the dominant phenotype and more dominant alleles

3. (1.1) List and define the 4 sources of genetic variation.

• Mutations • Crossing over • Independent Assortment • Random fertilization

• Jean Lamarck

• living things change over time • Living things change in order to become perfect or more complex • Evolution is based on 2 principles: i. Use and disuse ii. Inheritance of acquired characteristics