Character

Heritable feature that varies amongst individuals

True-breeding

Plants that produce offspring of the same variety when they self-pollinate

What do we mean when we use the terms monohybrid cross and dihybrid cross?

• A) A monohybrid cross involves a single parent, whereas a dihybrid cross involves two parents.
• B) A dihybrid cross involves organisms that are heterozygous for two characters that are being studied, and a monohybrid cross involves organisms that are heterozygous for only one character being studied.
• C) A monohybrid cross is performed for one generation, whereas a dihybrid cross is performed for two generations.
• D) A monohybrid cross results in a 9:3:3:1 ratio whereas a dihybrid cross gives a 3:1 ratio.

B

What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants?

• A) There is considerable genetic variation in garden peas.
• B) Traits are inherited in discrete units and are not the results of "blending."
• C) Recessive genes occur more frequently in the F1 generation than do dominant ones.
• D) Genes are composed of DNA.

B

3) How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE?

• A) 4
• B) 8
• C) 16
• D) 64

B

4) The individual with genotype AaBbCCDdEE can make many kinds of gametes. Which of the following is the major reason?

• A) recurrent mutations forming new alleles
• B) crossing over during prophase I
• C) different possible assortment of chromosomes into gametes
• D) the tendency for dominant alleles to segregate together

C

5) Mendel continued some of his experiments into the F2 or F3 generation to _____.

• A) obtain a larger number of offspring on which to base statistics
• B) observe whether or not a recessive trait would reappear
• C) observe whether or not the dominant trait would reappear
• D) distinguish which alleles were segregating

B

6) Which of the following statements about independent assortment and segregation is correct?

• A) Hh
• B) HhTt
• C) T
• D) HT

D

8) Mendel accounted for the observation that traits that had disappeared in the F1 generation reappeared in the F2 generation by proposing that _____.

• A) new mutations were frequently generated in the F2 progeny, "reinventing" traits that had been lost in the F1
• B) the mechanism controlling the appearance of traits was different between the F1 and the F2 plants
• C) traits can be dominant or recessive, and the recessive traits were obscured by the dominant ones in the F1
• D) members of the F1 generation had only one allele for each trait, but members of the F2 had two alleles for each trait

C

Hybridization

Mating 2 true breeding varieties

9) The fact that all seven of the pea plant traits studied by Mendel obeyed the principle of independent assortment most probably indicates which of the following?

• A) None of the traits obeyed the law of segregation.
• B) The diploid number of chromosomes in the pea plants was 7.
• C) All of the genes controlling the traits were located on the same chromosome.
• D) All of the genes controlling the traits behaved as if they were on different chromosomes.

D

Independent Assortment

Each pair of alleles segregates independently of any other pair of alleles.

Only applies to genes on different, non homologous chromosomes or those far apart on the same chromosome.

Allele

alternate versions of a gene

homozygote

An organism with two identical alleles for a character

Homozygous

refers to a particular gene that has identical alleles on both homologous chromosomes.

It is referred to by two capital letters (XX) for a dominant trait, and two lowercase letters (xx) for a recessive trait.

Homologous Chromosome

chromosome pairs (one from each parent) that are similar in length, gene position, and centromere location.

The position of the genes on each ________ is the same. However, the genes may contain different alleles.

Heterozygote

An organism with two different alleles for a gene

Non true-breeding

Phenotype

physical appearance

Genotype

genetic makeup

Testcross

Breeding the mystery individual with a homozygous recessive individual

If any offspring display the recessive phenotype, the mystery parent must be heterozygous

Mendel's observation of the segregation of alleles in gamete formation has its basis in which of the following phases of cell division?

• A) prophase I of meiosis
• B) anaphase II of meiosis
• C) metaphase II of meiosisD) anaphase I of meiosis

Linked Genes

Genes that are inherited together because they're located near each other on the same chromosome.

Parental type

Offspring with a phenotype matching one of the parental phenotypes

Recombinant type

Offspring with non parental phenotypes (new combination of traits)

Nonsidjunction

Pairs of homologous chromosomes do not separate normally during meiosis, resulting one gamete receiving two of the same type of chromosome and the other gamete receives no copy

Aneuploidy

result form the fertilization of gametes I which nondisjunction occurred. Offspring with this condition have an abnormal number of a particular chromosome.

Monosomic zygote

has only copy of a particular chromosome

trisomie zyogte

Has three copies of a particular chromosome.

4 types of changes in chromosome structure

• Deletion
• Duplication
• Inversion
• Translocation

Gene expression

The process by which DNA directs protein synthesis and includes translations and transcription

Ribosomes

Catalytic RNA Molecules that function as enzymes and can splice RNA

Histone Actylation

How something is expressed. Acetyl group attached to an animo acid in a histone tail.