Download Genetics

Do Now
• Take out DNA and genetics final review guide
• Write down any questions you have pertaining
to your final exam.
Genetics
1. What are the gametes of a male? Sperm
A female? Egg
2. Define phenotype and genotype.
Phenotype – the outward appearance of a trait (ex: Tall)
Genotype – the actual alleles that code for the trait (ex: Tt)
3. What are the products of mitosis? 2 diploid cells
Meiosis? 4 haploid cells Fertilization? 1 diploid cell
4.
Explain and give an example of the different types of
inheritance: incomplete dominance, polygenic, codominance,
multiple alleles. Practice punnett squares for each type of
inheritance!
Incomplete dominance:
A pattern of inheritance where the heterozygous gene produces an
intermediate trait.
Ex: Red (RR) flowered plant and a White (rr) flowered plant cross
to make pink flowers
R
r
r
0:4:0 0 red, 4 pink, 0 white
R
Rr
Rr
Rr
Rr
(4. continued)
Codominance:
A pattern of inheritance where neither allele is
recessive so the phenotypes of both alleles are
expressed in some way.
Ex: Cattle (red RR, white R’R’ and roan R’R)
(4. Continued)
Polygenic - traits are controlled by
several interacting genes, rather than by a pair
of alleles at a single locus.
Ex: Human hair and eye color
(4. continued)
Multiple Alleles - genes have more than two
different alleles--thus, "multiple" alleles
Type A - IA IA, IA i
Type B - IB IB, IB i
Type AB - IA IB
Type O - i i
(**What percent chance will
offspring have type A blood?**)
5. Define homozygous. And heterozygous.
Homozygous – pair of alleles that are the same
Ex: tt, TT
Heterozygous – pair of alleles that are different
Ex: Tt
6. What is a karyotype? What do you learn
from it?
Karyotype – a chart of metaphase chromosome
pair arranged by size and placement of
centromere
A karyotype will tell you the sex of a baby or
whether or not it has a genetic disorder like
Downs Syndrome, before birth.
DNA
1. A bonds with T ; C bonds with G (Think about it… could DNA be copied
without this paring of nitrogen bases??)
2. What is translocation? Substitution? Deletion? Point mutation? frameshift
mutation?
Translocation – A chromosome alteration in which a whole chromosome or
segment of a chromosome becomes attached to or interchanged with another
whole chromosome or segment
Substitution – a type of mutation due to replacement of one nucleotide in a DNA
sequence by another nucleotide.
Deletion – the absence of a segment of DNA; may be as small as a single base or
large enough to encompass one or more entire genes.(Ex: leaving a line)
Point mutation – Changing one nucleotide in a sequence of DNA caused by
substitution.
Frameshift mutation - An insertion or deletion involving the movement of the rest
of the sequence from the site of the mutation on.
DNA
3. A nucleotide consists of these three parts?
1. Nitrogenous base (A, T, C, or G)
2. Deoxyribose Sugar
3. Phosphate
4. What is transcription? Translation?
Transcription - is the coping of the DNA code to
mRNA
Translation – is converting the RNA code to
proteins(amino acids)
DNA
5. What is gel electrophoresis?
Gel electrophoresis is the process sorting
molecules like DNA by size and charge
6.What is genetic engineering?
Genetic engineering is the process of altering or
changing the DNA of an organism. For example
inserting a small fragment of frog DNA into
another species.
Do Now
• Take out evolution review guide to be checked
• Start to work on DNA and genetics until we
start to go over Evolution Answers.
• Homework: DNA and genetics due tomorrow
Evolution
1. How are fossils formed? Fossils can be formed in different ways.
Fossils can be found in sedimentary rock layers. Fossil insects may
have been trapped in ice or hardened into amber.
2. How do scientists learn about organisms of the past when studying
fossils? Scientists identify different kinds of fossils found in
sedimentary rock layers. Scientists can determine the approximate
time organism lived and the climate.
3. Define divergent, convergent, coevolution. Give an example of
each
Divergent - the evolution from a common ancestor to a variety of
species
Convergent- two unrelated species appear similar even though
they are geographically separated and genetically different.
Coevolution- two separate species evolve response to one another
Evolution
4. Explain the difference between analogous, homologous and
vestigial structures. Give an example of each.
Homologous structure – structures that have similar evolutionary
origin and structure but are adapted for different purposes.
Example: bat wing and human arm
Analogous structure – structures that do not have similar
evolutionary origin but have similar function. Example: bat wing,
bird wing and flying squirrel
Vestigial Structure – structures that are no longer used or needed
Example: the pelvic girdle and leg bones of an adult python
5. Define natural selection.
Natural Selection – is the survival and reproduction of the organisms
that are genetically best adapted to the environment.
Evolution
6. Explain the difference between disruptive, directional and stabilizing selection.
Give an example of each.
Stabilizing selection – the average individual of a population are favored.
Disruptive selection – individuals with both extreme forms of a trait are at a selective
advantage.
Directional selection – favors one extreme form of a trait in a population.
7. Define nonrandom mating and gene flow.
Gene flow – the movement of genes into and out of a gene pool
8. Who is Charles Darwin?
Charles Darwin is the founder of the modern evolutionary theory – evolution by
natural selection
9. What is geographic isolation?
Geographic isolation occurs when organisms of the same species are physically
separated by some geographic structure ex: mountain, lake…
10. What is camouflage?The ability to blend into the surrounding environment.
Ecology
1.How is nitrogen released to the abiotic parts
of the biosphere?
Decay by bacteria
2. How does carbon dioxide enter the biotic
parts of the biosphere?
Photosynthesis
Ecology
3. List and explain the different levels of
organization.
Biosphere - includes all parts of Earth where life
exists
Biome- many ecosystems with similar climates
Ecosystem – interactions between living(biotic)
and non-living(abiotic) factors
Community – interactions between several
species in an area
Population – groups of organisms of same
species interacting in a particular area
Organism – an individual
Ecology
4. Name and explain the differences between the 5
different types of symbiosis.
Predation – one organism (predator) captures and
consumes another organism (prey)
Parasitism – relationship where one organism is helped and
the other is harmed
Competition – the use of the same limited resource by 2 or
more organisms in the same place at the same time
Mutualism – relationship where both organisms benefit
Commensalism – relationship where one organism is
helped and the other is neither helped nor harmed
Ecology
5. Explain the difference between logistic and
exponential growth. What kind of curves
represent each?
Exponential growth is unrestricted population
growth or growth without any limiting factors
whereas logistic growth is population growth
that is restricted by limiting factors in the
environment.
Hint: it is very important to understand limiting
factors and carrying capacity!!!
Ecology
Exponential growth curveUnrestricted populations of
organisms
Logistic growth curve – a
population that grows
until it reaches its carrying
capacity has this shape
Ecology
6. What is a major threat to biodiversity?
Habitat Loss
7. Why is biodiversity important to people?
Biodiversity provides many resources for
humans (food, water, medicine, recreation,
beauty…)
Ecology
8. Explain the difference between primary and secondary
succession.
Primary succession occurs in an area where there
was no life before whereas secondary succession
occurs in an area where primary succession already
took place but was destroyed in a disaster or
disrupted.
An example of primary succession is the initial development of plant or animal communities
in an area where no soil initially exists (such as caused by a lava flow following volcanic
eruption or severe landslide that covered the land). The primary succession is important in
pioneering the area to create conditions favorable for the growth of other forms of plants
and animals.
Ecology
9. Define climax community.
A climax community is a stable ecosystem that
develops due to succession.
10.Explain the difference between a food web
and a food chain?
A food chain is the series of organisms showing
feeding relationships. A food web is a
combination of interconnected food chains.
Ecology
11.What do the arrows represent in a food
chain/web?
The arrows represent the movement of energy
in a food chain/web.
12. What happens to the energy as you move up
the food chain?
The amount of available energy decreases.
13. List the trophic levels from the bottom to the
top of the period.
Ecology
14. Where do decomposers get their energy?
Dead plants and animals
Example mushrooms growing off of dead logs
Classification
1. Define taxonomy and classification.
Taxonomy is the system for classifying and
identifying organisms.
Classification is the system for grouping similar
organisms together.
2. How do bacteria reproduce? Is it slow or
fast?
Binary fission, fast
Classification
3. Describe the structure of a virus. What
characteristics do they share with a living thing?
A virus is a nucleic acid that has a protective protein
cover.
Viruses like other living things contain nucleic acids
(DNA or RNA)
Ex: vaccines help to prevent you from getting some
viruses.
4.Define prokaryotic and eukaryotic.
Prokaryotic is a type of cell that lacks a nucleus.
Eukaryotic is a type of cell that has a nucleus.
Classification
5. Which kingdoms are prokaryotic?
Bacteria & Archaea
6. What is an antibody?
Chemicals made by the body that help destroy
viruses and harmful bacteria
7. Is the common cold caused by a bacteria or a
virus?
Virus
8. Do bacteria have a nucleus?
No
Classification
9. What is the main difference between a plant
and a fungi?
•The main difference between fungi and plants
is that fungi are heterotrophs while plants are
autotrophs.
•So fungi can NOT make their own food but
plants can.
Also…
• Be able to identify examples of niches,
habitats and limiting factors
• Be able to read a pedigree and determine
genotypes and identify carriers
• Be able to identify examples of the different
types of selection like disruptive selection
• Know the basic parts of plants and their
functions
• Be able to read and analyze different types of
graphs & tables