Genetics exam 1

nucleotide subunits

DNA is a polymer of ______

A phosphate group, a deoxyribose sugar, and a nitrogenous base (A, C, T, G)

A Nucleotide is composed of _____

C, 3
T, 2
Hydrogen

G bonds with ___ with __ bonds
A bonds with ____ with __ bonds
All base pairs are bonded by _____ bonds

5'

___ end of DNA has Phosphate group closer to it

opposite
biological information

the 2 strands of DNA have _____ orientation
DNA encodes ___

• Nucleotide

• Gene

• Chromosome, gene

• genome

• Nitrogenous group, phosphate, sugar

• sequence of DNA that encodes a protein

• DNA molecules and proteins assemble into these. each one contains many _____

• entire collection of chromosomes in each cell of an organism

24
23, 46, sex chromosomes

____ kinds of chromosomes
___ pairs, ____ individuals, ___ give the extra kind

• Amino acid

• 64

• 20

• structure, type, function

• ___: made up of three nucleotides

• four base pairs = _____ combination possibilities -____ diff amino acids

• order of these determines the ____ and ____ of the protein which, in turn, determines the diversity of protein ____

nucleotide- gene - chromosome- genome

Order from smallest to biggest
- gene, nucleotide, genome, chromosome

amino group, carboxyl group, and the side chain (alanine, etc)
peptide

Amino acid structure: ____
Amino acids are bonded together by ____ bonds

O=C-N-H + H-O-H

O=C-O-H + H-N-H =

Antibody
Immunoglobin

bind to specific foreign particles, such as viruses and bacteria, to help protect the body.
Ex?

Enzyme
hydrolase

carry out almost all of the thousands of chemical reactions that take place in cells. They also assist with the formation of new molecules by reading the genetic information stored in DNA.
Ex?

Messenger protein
Growth hormone

transmit signals to coordinate biological processes between different cells, tissues, and organs
Ex?

Structural Body Component Proteins
Actin

These proteins provide structure and support for cells. On a larger scale, they also allow the body to move.
Ex?

Transport/storage proteins
Ferritin

These proteins bind and carry atoms and small molecules within cells and throughout the body.
Ex?

unstable, single
DNA - RNA - protein
U, G

RNA is _____, has _____ strand
order DNA, protein, RNA
A binds to ___, C binds to ____

molecular speciation

• store, replicate

• intermediate, proteins

• catalyze biological processes

All organisms use the same _____

• DNA to ____ and _____ biological info

• RNA as an ______ in the production of _____

• proteins to _______

D, Aspartic acid

Asp

Nucleotide - gene - chromosome - genome

Order from smallest to biggest
- gene, nucleotide, genome, chromosome

T, Threonine

Thr

S, Serine

Ser

E, Glutamic acid

Glu

P, Proline

Pro

G, Glycine

Gly

A, Alanine

Ala

C, Cysteine

Cys

V, Valine

Val

M, Methionine

Met

I, Isoleucine

Ile

L, Leucine

Leu

Y, Tyrosine

Tyr

F, phenylalanine

Phe

H, histidine

His

K, lysine

Lys

R, Arganine

Arg

W, tryptophan

Trp

Q, glutamine

Gln

N, Asparagine

Asn

introns, exons

In eukaryotes, genes are composed of ____ and _____ which in rearrangements can combine to create new combinations

Regulatory networks

affect the location, timing, and level of expression of genes

• inactivate, consequences

• gene product

Genetic dissection of model organisms
- ______ a gene and observe the ______
- Make conclusions about the functions of a ____

• sequence of the entire genome

• genes

• differences between

Genomics

• Determine the _____

• Analyze all the ____ of an organism at once

• identify ______ individuals

exome
1%
disease

Portion of the genome that encodes exons
- __% of the genome
- contains most of the ____mutations

Gregor Mendel

first scientist to combine data collection, analysis, and theory to understand heredity.He inferred genetic laws about the appearance and disappearance of traits in different generations.

genes

basic units of heredity

Heredity

the way that genes transmit traits from parents to offspring

1. variation, diversity

2. observable variation

3. genetic laws, like and unlike

4. sexually reproducing organisms

4 general themes of Mendel's work:

1. _______ is widespread in nature and provides for continuously evolving (increasing) ________

2. ____is essential for following genes from one generation to another

3. Variation is inherited by ____, which can explain why like begets ____

4. Mendel's laws apply to all ______

Artificial selection

Purposeful control of mating by choice of parents for the next generation

What is inherited?
How is it inherited?
What is the role of chance in heredity?

Abbot Cyril Napp 's 3 questions

• The homunculus

• Blended inheritance

Two misleading theories:

• Inherited features of offspring are contributed mainly by only one parent

• Parental traits become mixed and changed in the offspring

1866, modern genetics

Mendel's paper "Experiments in plant hybrids" was published in ____ and became the cornerstone of _____.

self-fertilization
(anthers, ovules)

the fertilization of plants and some invertebrate animals by their own pollen or sperm rather than that of another individual (______ in the plants as the pollen and _____ as the eggs)

P, F1, all Heterozygous dominant, F2, 3:1 ratio of dominant to recessive
- homunculus and blending hypotheses

When using a homozygous dominant and homozygous recessive plant in the __ generation, the ____ generation is _____ and the ____ generation is ____
- these results disproved _____ and _____

Reciprocal cross
- same results either way

a pair of crosses between a male of one strain and a female of another, and vice versa.
Outcome?:

Genes

Units of inheritance

Alleles

Alternative forms of a single gene

monohybrids

Individuals with two different alleles for a single trait

Mendel's Law of Segregation

The two alleles for each trait separate during gamete formation. Two gametes, one from each parent, unite at random at fertilization

hybrid

What something is called that is heterozygous

Probability rule

probability of two independent events occurring together is the product of their individual probabilities

Sum rule

probability of either of two mutually exclusive events occurring is the sum of their individual probabilities

• P(1 and 2) = probability of event 1 X probability of event 2

• P(1 or 2) = probability of event 1 + probability of event 2 OR = +, AND= x

• What is the probability that event 1 AND event 2 will occur?

• What is the probability that event 1 OR event 2 will occur?

Phenotype

is an observable characteristic (e.g. yellow or green pea seeds)

Genotype

is a pair of alleles in an individual (e.g. YY or Yy)

Test cross

Involves the breeding of an individual with a phenotypically recessive individual, in order to determine the zygosity of the former by analyzing proportions of offspring phenotypes.

Parental
Recombinant
You get both parental types and recombinant types

Mendels Dihybrid cross:
Mendel asked whether all the F2 progeny would be ______ types (yellow round and green wrinkled- original) or would some be ______ types (yellow wrinkled and green round- different)?
Answer:

dihybrid

______ cross gives both parental and recombinant types

1:1:1:1
9:3:3:1

Dihybrid cross that starts with YYRR and yyrr ends with ______ ratio in the F1 generation and a ____ ration in the F2 generation

Mendel's law of independent assortment

During gamete formation, different pairs of alleles segregate independently of each other
Ex.) Y is just as likely to assort with R as it is with r

(Each trait is inherited in a 3:1 ratio•Ratio of yellow (dominant) to green (recessive) = 3:1)

P(yellow, wrinkled)= P(yellow) X P(wrinkled)
= 3/4 X 1/4
= 3/16

Use product rule to determine the ratio of yellow, wrinkled peas in the dihybrid cross

• enzyme, phenotype

• normally functioning

• functional

A specific gene determines a specific ______, whose activity may affect _______
•A dominant allele usually determines a _______ protein.
•A recessive allele usually does not encode a protein.

Pedigree

orderly diagrams of a family's relevant genetic features
Includes as many generations as possible (ideally, at least both sets of grandparents of an affected person)

• square

• circle

• diamond

• diseased

• multiple progeny

• deceased/dead

• incest

Pedigree:
Male is shown with a _____
Female is shown with a _____
unspecified sex is shown with a _____
colored in means ______
numbers inside means ______
slash line through means ______
double line connecting means ____

1. at least one affected parent

2. vertical pattern of inheritance

3. heterozygotes

Three key aspects of pedigrees with dominant traits:

1. Affected children always have _______

2. As a result, dominant traits show a _______

3. Two affected parents can produce unaffected children, if both parents are _______

1. two unaffected carriers, consanguineous

2. be affected

3. horizontal

4. vertical, common

Four keys aspects of pedigrees with recessive traits:

1. Affected individuals can be the children of_______ , particularly as a result of ____ matings

2. All the children of two affected parents should be affected

3. Rare recessive traits show a ______ pattern of inheritance

4. Recessive traits may show a ______ pattern of inheritance if the trait is extremely ______ in the population

progeny

• dominant or recessive

• two

• multiple

• gene-environment

Crosses of pure-breeding lines can result in _____ phenotypes that don' t appear to follow Mendel's rules. Reasons?
-No definitively _____ allele
•More than ___ alleles exist
•________ genes involved
•________ interactions

Pleiotropy
(Homozygotes- recessive yellow mice)

One gene may contribute to several characteristics
(With these genes, ______ can be lethal

Complete dominance (white and blue makes white)

Hybrid resembles one of the two parents

Incomplete Dominance (white and blue makes a light blue)

Hybrid resembles neither parent

Codominance (white and blue make white-blue striped)

Hybrid shows traits from both parents

2:1:1 pink, red, white (incomplete dominance)
•AA = 2 normal alleles = red color
•Aa = 1 normal allele = pink color (less enzyme)
•aa = 0 normal alleles = white color (no functional enzyme)

Phenotype ratios reflect the genotype ratios
•AA = ______ alleles = ___color
•Aa = ______allele = _____ color (____ enzyme)
•aa =_______ alleles = ____ color (____ enzyme)

codominance
1:2:1

In _____, the F1 hybrids display traits of both parents
In the F2 generation, hybrid ratio is _____

• IA and IB

• A, A, Antibodies against B

• B, B, Antibodies against A

• both, AB, No antibodies -neither, O, Antibodies against A and B IA and IB are codominant, IA and IB are dominant to i

Blood types: -Two alleles, _______, result in different sugars

• IA IA individuals have __ sugar, type?, Antibodies?

• IB IB individuals have __ sugar, type?, Antibodies?

• IA IB individuals have ____ sugar, type?, Antibodies?

• i i individuals have __ sugar, type?, Antibodies?

proteins, biochemical functions
laws of segregation

Type of dominance (complete, incomplete dominance, codominance) depends on the type of ______ encoded and the _____ of the proteins.
Variation in dominance relations do not negate Mendel's _______

• 2

• segregate

• 2

• second, pairs

• ex: could be like 7 alleles, but you only carry two

A gene can have more than ___ alleles

• Multiple alleles of a gene can ____ in populations

• Each individual can carry only _____ alleles

• Dominance relations are always relative to a ____ allele and are unique to a ____ of alleles

• ex?

Dominance relations (Some of the alleles are more dominant than the others- seeds)

Genes with more than 2 alleles:
- Reciprocal crosses between pairs of pure-breeding lines is used to determine ______

mutations
- gamete-producing

_____ are the source of new alleles
- If mutations occur in ______ cells, they can be transmitted to offspring

Allele frequency

is the percentage of the total number of gene copies for one allele in a population

Wild type (+) allele

Most common allele is usually the

Mutant allele

Rare allele is considered a

• monomorphic

• polymorphic

• Gene w/ only one common wild-type allele is

• Gene w/ more than one common allele is

common variants

High-frequency alleles of polymorphic genes are

2:1

A _____ ratio is indicative of a recessive lethal allele

Heterozygotes, homozygotes

With some pleiotropic genes, _________ can have a visible phenotype, and ____ can be lethal

Novel phenotypes
complementary gene action, epistasis, redundancy
vary from the 9:3:3:1 ratio

Two genes can interact to determine one trait
•______ can result from gene interactions.
Can result in... 3
In all of these cases, the F2 generation phenotypes from the dihybrid cross ____

epistasis

allele at one gene masks the phenotype of alleles at another gene.

redundant

Genes that perform the same function are

complementary gene action

Fewer phenotypes maybe observed due to

9:3:3:1

_____ ratio in F2 suggests two independently assorting genes for seed coat color or other traits