adv._bio_final_ex_study_guide.docx - Course-Notes.Org

alarmduckΒιοτεχνολογία

12 Δεκ 2012 (πριν από 4 χρόνια και 4 μήνες)

244 εμφανίσεις

Chapter 11 Genetics


Sec. 11
-
1 The Work of Gregor Mendel

Key Concepts:

What is the principle of dominance?


Some alleles are dominant, others are recessive

What happens during segregation?


Alleles are separated so each gamete carries a single copy
of
each gene

When does segregation happen?


During gamete formation (meiosis)


Vocabulary:

Genetics


S
cientific study of heredity

True
-
breeding


If allowed to self
-
pollinate, they would produce identical offspring

Trait


S
pecific characteristic

Hybrid


C
ross between parents with different traits

Gene


Chemical factors that determine traits

Allele


Different forms of a gene

Segregation


separation [of alleles]

Gamete


sex cells

P


parent generation

F
1



First filial generation (child)

F
2



Second fil
ial generation


Sec. 11
-
2 Probability and Punne
t
t Squares

Vocabulary:

Probability


The likelihood that a particular event will occur

Punnett Square


Diagram showing the possible gene combinations that will occur in future
generations

Homozygous


Two ide
ntical alleles for a particular trait (TT)

Heterozygous


Two different alleles for a particular trait (Tt)

Phenotype


Physical characteristics

Genotype


Genetic make
-
up


Sec. 11
-
3 Exploring Mendelian Genetics (Independent Assortment only)

Vocabulary:

Independent Assortment


Genes that segregate independently and do not influence each
other’s inheritance patterns (seed size/shape vs. color)


Sec. 11
-
4 Meiosis

Key Concepts:

What happens during the process of meiosis?


Reduction division

What is the
main event of the first meiotic division?


Prophase I


How is meiosis different from mitosis?


Mitosis produces
two diploid (identical)
cells;

meiosis
produces four haploid (different) cells


Vocabulary:

Homologous


Each of the four chromosomes that cam
e from the male parent has
corresponding chromosomes from the female parent

Diploid


A cell that contains both sets of homologous chromosomes (2N)

Haploid


A cell contains only a single set of chromosomes (single set of genes) (N)

Meiosis


Reduction div
ision in which the chromosome number is halved through separation of
homologous chromosomes

Tetrad


Each chromosome pairs with its corresponding homologous chromosome

Synapsis


The pairing of two homologous chromosomes during Prophase I

Crossing
-
over/Rec
ombination


Exchanging of portions of chromatids


happens during tetrad


Sec. 11
-
5 Linkage and Gene Maps (Key Concept & Vocabulary only)

Key Concept
s:

What structures actually sort independently?


Chromosomes assort independently, not genes


Vocabulary
:

Gene Map


Shows the relative locations of each gene on a chromosome

Linkage


Genes are linked (show up together consistently) so no new combinations show up;
no intermediate phenotypes


Chapter 12 DNA & RNA


Sec. 12
-
1 DNA (omit scientists & classic
experiments)

Key Concepts
:

What is the overall structure of the DNA molecule?


A DNA molecule, as discovered by Watson
and Crick, is a double
-
helix (two strands wound around each other)

What are the three parts of a nucleotide of DNA?


DNA is made up of
deoxyribose, phosphate,
and a nitrogenous base

…of RNA?


Ribose, phosphate, and a nitrogenous base (Uracil instead of Thymine)


it is also
one strand


Vocabulary:

Nucleotide


The basic make
-
up of DNA; it is made up of deoxyribose, phosphate, and a
nitro
genous base


Base pairing


Hydrogen bonds can only form between certain base pairs

adenine with
thymine, guanine with cytosine

Purines


Adenine and Guanine

Pyrimidines


Cytosine and Thymine

Chargaff’s Rules


[A] = [T] and [G] = [C]


Sec. 12
-
2 Chromoso
mes and DNA Replication

Key Concepts
:

What happens during DNA Replication?
-

During DNA Replication, the DNA molecule separates
into two strands, and then produces two new complementary strands following the rules of
base pairing. Each strand of the double

helix of DNA serves as a template, or model, for the new
strand


Vocabulary:

Chromatin
-

Eukaryotic chromosomes contain both DNA and protein, tightly packed together to
form this substance

Histone
-

DNA of the chromatin is tightly packed around proteins
called histones

Nucleosome


Nucleosomes are the reason this length can be achieved


each nucleosome is
super
-
coiled; nucleosomes play a role in regulating how genes are read


changes which
proteins are produced

Replication
-

Duplication of DNA before a
cell divides (KEY CONCEPT: During DNA Replication,
the DNA molecule separates into two strands, then produces two new complementary strands
following the rules of base pairing. Each strand of the double helix of DNA serves as a template,
or model, for the
new strand

DNA Polymerase
-

The principle enzyme involved in DNA replication; it polymerizes individual
nucleotides to produce DNA

Replication Fork
-

The

replication fork

is a structure that forms within the nucleus during

DNA
replication
. It is created by

helices
, which break the

hy
drogen bonds

holding the
two

DNA

strands together. The resulting structure has two branching "prongs", each one made
up of a single strand of DNA.



Sec. 12
-
3 RNA and Protein Synthesis

Key Concepts
:

What are the three main types of RNA?
-

Messenger RNA (mRNA), ribosomal RNA (rRNA), and
transfer RNA (tRNA)

What is transcription?
-

During transcription, RNA polymerase binds to DNA and separates the
DNA strands. RNA polymerase then uses one strand of
DNA as a template (model) from which
nucleotides are assembled into a strand of RNA

What is translation?
-

During translation, the cell uses information from messenger RNA to
produce proteins

Translation Process:

o

RNA transcribed from DNA

o

mRNA molecule in t
he cytoplasm attaches to a ribosome

o

The ribosome forms a peptide bond between the first and second amino acids,
methionine and phenylalanine

o

The chain continues to grow until it reaches a stop codon on the mRNA
molecule


Vocabulary:

Messenger RNA (abbrevia
tion: __mRNA__)
-

The RNA molecules that carry copies of instructions
from genes; they serve as “messengers” to the rest of the cell

Ribosomal RNA (abbreviation: __rRNA__)
-

Ribosomes made up of several dozen proteins, as
well as this form of RNA

Transfer
RNA (abbreviation: __tRNA__)
-

During construction of a protein, this type of RNA
transfers each amino acid to the ribosome as it is specified by coded messages in mRNA

Transcription
-

RNA molecules are produced by copying part of the nucleotide sequence o
n DNA
into a complementary sequence in RNA

RNA Polymerase
-

During transcription, RNA polymerase binds to DNA and separates the DNA
strands. RNA polymerase then uses one strand of DNA as a template (model) from which
nucleotides are assembled into a strand

of RNA

Promoter
-

The region of DNA that acts as the initial binding site for RNA polymerase

Intron
-

A stretch of DNA that interrupts a gene and does not contribute to the specification of a
protein

Exon
-

Any segment of a discontinuous gene the segments

of which are separated by introns

Codon
-

A sequence of three adjacent nucleotides constituting the genetic code that determines
the insertion of a specific amino acid in a polypeptide chain during protein synthesis or the
signal to stop protein synthesis

Translation
-

The process by which messenger RNA directs the amino acid sequence of a growing
polypeptide during protein synthesis

Anticodon
-

A sequence of three adjacent nucleotides in transfer RNA that binds to a
corresponding codon in messenger RNA an
d designates a specific amino acid during protein
synthesis


Sec. 12
-
4 Mutations

Key Concepts:

What are gene mutations?
-

Two types of mutations:



Point mutations (substitutions)



Frameshift mutations (insertion/deletion)


can affect protein so that it is
unable to
perform properly

What are chromosomal mutations?
-

Chromosomal mutations change the number or structure
of a chromosome:



Deletion



Duplication



Inversion



Translocation


Vocabulary:

Mutation
-

Changes in DNA sequence that affect genetic information

Point mutation
-

Mutations that affect one nucleotide; they occur in one specific place

Frameshift mutation
-

Mutations that shift the “reading frame” of the genetic message (i.e.
deletion, insertion)

Chromosomal mutation (not bolded in text; see p. 308)
-

Chromosomal mutations change the
number or structure of a chromosome: Deletion, Duplication, Inversion, and Translocation


Chapter 13 Biotechnology


Sec. 13
-
1 Changing the Living World


Sec. 13
-
2 Manipulating DNA


Sec. 13
-
3 Cell Transformation


Sec.
13
-
4 Applications of Genetic Engineering


Chapter 14 Human Genome


Sec. 14
-
1 Human Heredity

Key concepts:

How is gender determined?
-

All eggs carry a single X chromosome (23X). However, half of all
the sperm cells carry an X chromosome (23X), while the
other half carries a Y chromosome
(23Y). This ensures that just about half of the zygotes will be 46XX and half will be 46XY

How do small changes in DNA cause genetic disorders?

-

In both cystic fibrosis and sickle cell
disease, a small change in the DNA o
f a single gene affects the structure of a protein, causing a
serious genetic disorder.


Vocabulary:

Karyotype


A picture of chromosomes taken during mitosis arranged in corresponding pairs

Sex Chromosome


Two chromosomes (X and Y) that determine an indi
vidual’s gender

Autosome


The remaining 44 chromosomes in human DNA

Pedigree


Chart that shows the relationships within a family, which can be used to help with
the task of determining the inheritance of a trait


Sec. 14
-
2 Human Chromosomes

**Most sex
-
li
nked traits are recessive

**Most are located on the X
-
chromosome (passed by the mother)

Key concepts:

Why are sex
-
linked disorders more common in males than in females?

-

Males have just one X
chromosome. Thus, all X
-
linked alleles are expressed in males,
even if they are recessive

What is non
-
disjunction, and what problems does it cause?

-

If non
-
disjunction occurs, abnormal
numbers of chromosomes may find their way into gametes, and a disorder of chromosome
numbers may result (extra chromosomes, or delete
d chromosomes)


Vocabulary:

Sex
-
linked gene


Genes located on sex chromosomes; many sex
-
linked genes are found on the
X chromosome. More than 100 sex
-
linked genetic disorders have been mapped to the X
chromosome.

Non
-
disjunction (“not coming apart”)


Th
e most common error in meiosis where homologous
chromosomes fail to separate


Sec. 14
-
3 Human Molecular Genetics (Key Concepts & Vocabulary only)

Key concepts:

What is the goal of the human genome project?



The human genome project is an attempt to
seque
nce all human DNA (Francis Collin & Craig Venter)

What is gene therapy?



In gene therapy, an absent or faulty gene is replaced by a normal,
working gene


Vocabulary:

DNA Fingerprinting


A powerful new tool for the identification of individuals; analyzes
sections
of DNA that have little or known function but vary widely from one individual to another


AP Biology Laboratory 7:

Genetics of Drosophila (“fly packet”)

see especially Introduction & Background



Flies are

o

Cheap

o

Easy to maintain

o

Small

o

Breed
quickly/live a short life

o

Can’t hurt you