Download Spring Final Review

Spring Final Review
DNA Unit
- Where does DNA replication take place in a cell? Nucleus
- Given one side of the DNA strand (AGTCATCGA), what is the other side of the DNA
strand?
TCAGTAGCT
What would be the mRNA strand? UCAGUAGCU
- What scientists are credited with the shape of a DNA molecule? Rosalind Franklin, Watson
and Crick
- What is the shape of a DNA molecule? Alpha double helix
- What message does mRNA carry? The directions to match Amino acids sequence and make a
protein
- What is a clone? And exact DNA copy of an existing organism. A identical twins could be
said to be closes. an organism or cell, or group of organisms or cells, produced asexually from
one ancestor or stock, to which they are genetically identical
- Each organism has a unique combination of
characteristics encoded in molecules of what? DNA
- Give the following mRNA strand, write the correct
amino acid sequence for it: AUCCCGCACGUA
be able to go from mRNA to amino acids
AUC – Ile CCG Pro CAC His
knew the steps and location of
GUA Val
know the steps in the diagram. Locations and if nucleic acids, or amino acids.
DNA Replication in the nucleus, DNA to make a new strand of DNA. Nucleic acid to Nucleic
acid A-T. T-A, C-G, G-C
Transcription in the nucleus, DNA to mRNA, nucleic acid to nucleic acid
DNA
mRNA
A
U
T
A
G
C
C
G
Translation in the cytoplasm mRNA finds a ribosome either free in cytoplasm or bound to the
Endoplasmic reticulum ER. The ribosome reads the mRNA three nucleic acids at a time- codonand matches each codon to the anticodon of the tRNA carrying the correct amino acid the
ribosome joins the amino acids together with peptide or covalent bonds to make a protein or
polypeptide.
DNA translation is the process that converts an mRNA sequence into a string of amino acids that
form a protein
See the mRNA amino acid chart last page.
mRNA A
U
C
G
tRNA
A
G
C
U
Protein Synthesis
Protein synthesis is accomplished through a process called translation. After DNA is transcribed into a
messenger RNA (mRNA) molecule during transcription, the mRNA must be translated to produce a
protein. In translation, mRNA along with transfer RNA (tRNA) and ribosomes work together to produce
proteins
What are the start codon and the stop codon sequence?
Start AUG
Stop UAG UAA
UGA
Cell Reproduction Unit
Know the cell cycle diagram, what happens in each stage.
Stages of cell cycle
Interphase:
- G1(Growth 1): The cell grows to accomodate new genetic information
- S(synthesis): The cell duplicates its DNA for the two daughter cells
- G2(Grwoth 2): The cell grows once again for there to be enough cytoplasm for the daughter
cells
Mitosis:
-Prophase: Chromatin is organized into chromosomes, two centrosomes move to the poles of the
cells, and the nuclear envelope breaks down
-Prometaphase: The nuclear envelope is gone, the spindle fibers start to form, and the
chromosomes start to move towards the equator of te cell
-Metaphase: The chromosomes align in the middle of the cell
-Anaphase: The chromosomes are split apart into chromatids by the spindle fibers and are
starting to be pulled to opposite poles
-Telophase: The chromatids are enveloped in a new nuclear envelope in the two new daughter
cells making two seperate nuclei
Cytokinesis:
The cells cytoplasm splits and forms the two new daughter cells which are identical to the parent
cell. Both have their own nucleus and DNA
- In what stage of the cell cycle does the nucleus and its contents divide?
During Mitosis in Telophase
-
What is the difference between asexual and sexual reproduction?
-
Sexual reproduction allows for a greater shuffling of the genes in a new individual
allowing for changes to help its survival.
Asexual reproduction can be a clone of the original cell, as basic as making a replacement cell..
- What is the correct order of the cell cycle? G1, S, G2, Mitosis cytokinesis
- What is the correct order of the phases of mitosis?
Prophase, Metaphase, Anaphase and Telophase
- Why are stem cells so important (what can they do that most cells can not?
they can differentiate into any type of cell anywhere in the body.
- What happens during interphase?
G1 the cell grows and does it function in the body= it works, 1 set of 2 of each of the
chromosome 2N
S phase the duplication of the DNA go from 2N to 4N, doubling the chromosomes. The cell
organelles are also copied at this time.
G2 a rest period and a time to store energy and prepare for duplication of the cell.
- How is mitosis used in a single-celled organism?
Mitosis in a single cell organism is the method of reproduction
What is the difference between a cancer cell and a normal cell?
Cancer cells just keep duplication and to not take time to do any work in the organism.
Chromosomes and Meiosis Unit
- What is meiosis? Meiosis is the method of preparing the gametes, or sex cells for reproduction
in multicelled organisms. It allows for shuffling of the chromosomes- crossing over, and
reducing the chromosome number to half of a set of chromosomes or N
- How many of each type of chromosome does a person receive from mom and dad? You
get half of your chromosomes from each parent. One of each matching chromosome pair.
- How many chromosomes does a human have? Total of 46, 22 autosomal pairs that carry the
information for the body and 1 pair of sex chromosomes that determine gender of the individual
and the X chromosome contain many other required genetic traits.
- What statement is true for homologous chromosomes?
Homologous chromosomes are the two matching chromosomes that make up a pair.
- A cell made by meiosis has how many chromosomes?
Half the number or 23 chromosomes
- What is the difference between a diploid cell and a haploid cell? Give an example of each.
Comparison chart
Diploid versus Haploid comparison chart
Diploid
About
Cell Division
and Growth
Examples
Haploid
Diploid cells contain two complete
sets (2n) of chromosomes.
Haploid cells have half the number
of chromosomes (n) as diploid - i.e.
a haploid cell contains only one
complete set of chromosomes.
Diploid cells reproduce by mitosis
making daughter cells that are
exact replicas.
Haploid cells are a result of the
process of meiosis, a type of cell
division in which diploid cells divide
to give rise to haploid germ cells. A
haploid cell will merge with
another haploid cell at fertilization.
Skin, blood, muscle cells (also
known as somatic cells)
Cells used in sexual reproduction,
sperm and ova (also known as
Gametes).
- If an organism has a haploid number of 14, how many chromosomes are in its sex cells?
How many are in its body cells?
Sex cells 14 sex cells or gametes are haploid
Body cells 28 body cells are diploid
Genetics Unit
- What is the definition of genetics?
the study of heredity and the variation of inherited characteristics
- What does the term heredity mean?
Heredity is the passing of traits from parents to their offspring, either through asexual
reproduction or sexual reproduction. This is the process by which an offspring cell or organism
acquires or becomes predisposed to the characteristics of its parent cell or organism. Through
heredity, variations exhibited by individuals can accumulate and cause some species to evolve
through the natural selection of specific phenotype traits
- Who is the “father” of modern genetics?
Gregor Mendel, Austrian Abbot/monk, did experiments with peas, defined modern terms of
genetics and the three laws of genetics
- Name 2 examples of biological traits?
Eye color, height they are heritable characterizes passed from parents to offspring.
- Hair color and eye color are examples of a person’s what? Genetic traits
- How are the terms genotype and phenotype related? How are they different?
Genotype is the traits you inherited from your parents, while phenotype is what we see in an
individual. It is the result of genotype and environmental effects.
- Draw a Punnett square for the following cross: BB X Bb
B
B
b
B
BB
BB
Bb
Bb
Give the genotypic and phenotypic ratio of the offspring
Geneotypic ratio is
Dominant Dominant : Dominant recessive : recessive
Phenotypic ration is what we see so Dominant to recessive
In the example above Genotypic ratio is 2:2 :0
Phenotypic ration is 4:0
- What is the phenotypic ratio of a cross between two parents that are heterozygous (Gg X
Gg)?
G
g
Genotypic ratio 1: 2:1
G
GG
Gg
Phenotypic ratio
3:1
g
Gg
gg
- How is the F1 Generation made? What are the offspring of the F1 Generation called?
You have two original parents the p generation their offspring are the F1. if you cross/bred two
F1 you get the F2 generation
- Draw a Punnett Square for the following cross: GgIi X GgIi
gametes GI, Gi, gI gi
GI
Gi
gI
gi
GGII
GGIi
GgII
GgIi
GGIi
Gi
GGii
GgIi
Ggii
gI
GgII
GgIi
ggII
ggIi
gi
GgIi
Ggii
ggIi
ggii
9: 3:3:1
- What is the difference between a monohybrid cross and a dihybrid cross?
Monohybrid cross deals with the inheritance and probability of offspring combinations for one
trait Gg X GG
Dihybrid cross is the inheritance and probability of the offspring combinations for two traits at a
time. GgTT X ggTt
What types of genes are more likely to be inherited together?
Linked genes sit close together on a chromosome, making them likely to be inherited together.
Genes on separate chromosomes are never linked. Genetic linkage is the tendency of alleles
that are close together on a chromosome to be inherited together during the meiosis phase of
sexual reproduction. Genes whose loci are nearer to each other are less likely to be separated
onto different chromatids during chromosomal crossover, and are therefore said to be genetically
linked. In other words, the nearer two genes are on a chromosome, the lower is the chance of a
swap occurring between them, and the more likely they are to be inherited together.
What factors play a role determining your phenotype?
Your genes carry the instructions for the growth and development of your body. However, your
phenotype is influenced during embryonic development and throughout your life by
environmental factors. Environmental factors are many and varied and include diet, climate,
illness, accidents and stress.
- If a genetic disorder is found mostly in males, the disorder is most likely what kind?
Sexlinked, genes found on the X chromosome and the Y chromosome lacks those genes
- What does it mean for a person to be a carrier for a disorder?
it means they are a hybrid, or heterozygous for the trait, one gene the disorder and one gene for a
normal allele for the trait affected.
Explain why most sex-linked disorders occur in males? (Hint: Think what makes a male
different than a woman)
A particularly important category of genetic linkage has to do with the X and Y sex
chromosomes. These not only carry the genes that determine male and female traits
but also those for some other characteristics as well. Genes that are carried by either
sex chromosome are said to be sex linked.
Men normally have an X and a Y combination of sex chromosomes, while women have two X's.
Since only men inherit Y chromosomes, they are the only ones to inherit Y-linked traits. Men
and women can get the X-linked ones since both inherit X chromosomes. X-linked recessive
traits that are not related to feminine body characteristics are primarily expressed in the
observable characteristics, or phenotype
, of men. This is due to the fact that men only have
one X chromosome. Subsequently, genes on that chromosome not coding for gender are usually
expressed in the male phenotype even if they are recessive since there are no corresponding
genes on the Y chromosome in most cases. In women, a recessive allele on one X chromosome
is often masked in their phenotype by a dominant normal allele on the other. This explains why
women are frequently carriers of X-linked traits but more rarely have them expressed in their
own phenotypes
If a woman is a carrier of an X-linked recessive
allele for a disorder and her mate does not have
it, their boys will have a 50% chance of inheriting
the disorder. None of their girls will have it, but
half of them are likely to be carriers.
If a man has an X-linked recessive disorder and his
mate does not carry the allele for it, all of their girls
will be carriers. None of their boys will inherit the
harmful allele. Only girls receive X chromosomes
from their fathers.
Classification Unit
Reminder of terms: DNA similarities & differences – amino acid sequences
- What is taxonomy?
The science concerned with classification, especially of organisms; systematics.
- What scientist helped develop the classification system we use today?
Linnaeus developed the modern system of naming known as binomial nomenclature, a two-word
name (Genus & species)
- What are the levels of organization from largest to smallest?
Domain– broadest – most inclusive
Kingdom
Phylum (or "division" in plants)
Class
Order
Family
Genus
Species – most specific & most exclusive
(plants subdivided into varieties)
( bacteria subdivided into strains)
(dogs subdivided into breeds)
- What classification systems are used to include time and relationships between organisms
Evolutionary Classification
 Phylogenetic systematics (phylogeny)
o Groups species into larger categories that reflect theoretical lines of evolutionary
descent rather than overall similarities & differences.
 Cladistic analysis:
o Clades - A group of species that theorizes a single common ancestor & all
descendents of that ancestor – living or extinct (theory of common descent)
o Derived characteristics – trait that arises & is passed on to descendents (descent
with modification theory)
 Cladograms :
 Theorizes how organisms are related based on derived
characteristics such as feathers, hair, scales, etc.
 Theorizes how evolutionary lines branched off from common
ancestors
Phylogenetic trees are branching diagrams showing how organisms are potentially related



Fossil records help place these proposed relationships on a phylogenetic tree
Possible common ancestor is shown at the base of the tree
Organisms thought to be more modern (newer) are shown at tips of branches
Example Questions: Cladogram
1. Which organism(s) have jaws, lungs, claws or nails, but not fur or mammary glands?
2. List the features that salamanders:
a. Have: __________________________________________
b. Don’t have: ______________________________________
What we look at to determine evolution and relationships?
Systematics is the part of science that deals with grouping organisms and determining how they are related. It
can be divided into two main branches:


Taxonomy focuses on classifying, naming, and grouping organisms. A group, or taxon, can be a
population, a species, a genus, or a higher-level grouping, such as family, order, class, phylum,
kingdom, or domain. The plural of taxon is taxa.
Phylogenetics is the study of determining evolutionary relationships, or patterns of descent of
organisms.
- What parts make up the scientific name of an organism?
binomial nomenclature, a two-word name (Genus & species)
- Why scientists do not use common names when talking about organisms?
Common names change with location, time period, and are complicated and not always correct
in identification e.g mudpuppy, silverfish.
- What language are scientific names written in?
Latin, it is a dead language so its meanings do not change
Evolution Unit
What is Evolution=defined at the process of change over time in population.
Evolution is the process by which modern organisms have descended from ancient ancestors.
Evolution is responsible for both the remarkable similarities we see across all life and the
amazing diversity of that life.
What is natural selection? Who proposed Evolution through natural selection?
It is the process by which biological organisms with favorable traits survive and reproduce more
successfully than organisms that do not possess such traits. Charles Darwin Proposed Evolution
through Natural Selection.
What is convergent evolution? Give an example
When environment dictates the evolution of similar structures that have similar functions but are
from different, un-related species. Ex. Include wings of a bat, bird, or a dragonfly. All have
same function and shape, but formed in obviously different organisms.
What is divergent evolution? Give an example
One species gives rise to many species over time. These new species can trace origin back to a
common ancestor. Example: Darwin’s Finches or the tortoises he studied.
What is speciation? Give an example.
Evolution of a new species because of geographic, reproductive isolation, or a change in the
number of chromosomes. Ex. Polyploidy in some species of plants, Abert squirrels separated by
Grand Canyon.
- What is an adaptation?
Different tissues shaped to do similar things to meet the same need.
- Give an example of how one animal could be adapted for an environment better than
another.
Animals that have adapted to their environments and do well would include polar bears to the
cold and availability of food. Where as a polar bear in the topics would die since it could not
keep cool.
- The hind legs of a whale and wings of an ostrich are known as what kind of structures?
Vestigial organs or structures or those that no longer serve a useful function
- What happens to organisms that are well adapted to their environment?
The are the fittest for that environment. They will survive and reproduce
- What is sexual selection? Give an example
a type of natural selection where either sex can alter the mating selection. Sexual selection acts
on an organism's ability to obtain (often by any means necessary) a mate.
Selection makes many organisms go to extreme lengths for sex: peacocks maintain elaborate
tails, elephant seals fight over territories, fruit flies perform dances, and some species deliver
persuasive gifts. After all, what female Mormon cricket could resist the gift of a juicy spermpacket? Going to even more extreme lengths, the male redback spider literally flings itself into
the jaws of death in order to mate successfully.
Sexual selection is often powerful enough to produce features that are harmful to the individual's
survival. For example, extravagant and colorful tail feathers or fins are likely to attract predators
as well as interested members of the opposite sex.
- A population that has a wide range of phenotypes would also have a large amount of
what?
Genetic variation of gene alleles
- Draw a standard bell curve. Then draw what happens to this curve during stabilizing
selection, directional selection, and disruptive selection.
- What happens when some organisms leave a population and migrate into another area
and join another population?
Gene Flow = genes from one population move to another population
This results in a change in allele frequency in the mixed population
- Explain what happens during geographic isolation of a population. Give an example of
how this might occur.
•
New species will arise more quickly if they are geographically isolated. Natural barriers
such as mountains, deserts, rivers or landslides can separate members of a population. If
they can no longer interbreed they may change enough by natural selection to become a
separate species. (ex. Darwin’s finches)
•
The loss of the ability to interbreed is called reproductive isolation. Sometimes this is
caused by changes in reproductive organs such that the offspring will not survive.
•
Temperal isolation Sometimes this type of isolation is caused by changes in courtship
behavior or the timing of mating cycles.
- Darwin’s finches had different shaped beaks but Darwin hypothesized what about these
finches?
That they all originated from one mainland species of finch that was blown to the closest island
- What is a homologous structure?

Reminder of Terms:
 HOMOLOGOUS structures have the same structure, but different functions & a
possible relationship between the organisms.
 EXAMPLE: The bones in a bat's wing, human's arm, penguin's flipper are
the same (homologous), but the function is different
 ANALOGOUS structures have the same function, but different structures & do
not show a close relationship (insect wing & bird's wing)
 EMBRYOLOGY: Similarity in development
 EXAMPLE: vertebrate embryos all have tail & gill slits
Convergent evolution Different species with parts shaped the same by the pressures of natural
selection to meet the same environmental needs analogous structures
Analogous structures Different tissues shaped to do similar things to meet the same need.
Vestigial organs or structures
Practice label