Genetics Midterm 1

ingredients to baby

1 set of non-homologous chromosomes from mom, and 1 set from dad 1 homolog fr mom, 1 homolog fr dad

an organism is homozygous for 8 genes and heterozygous for 3 genes. how many different genotypes would you expect in the gametes from this organism?

11

incomplete dominance or codominance ratio

1:2:1

diploid

2 sets of chromosomes

Chromosomes are made of

2 sister chromatids

complete dominance ratio

3:1

aneuploid

Abnormal number of chromosomes.

allele

An alternative form of a gene.

Genotype

An organism's genetic makeup, or allele combinations.

autosome

Any chromosome that is not a sex chromosome

homologous chromosomes

Chromosomes that have the same sequence of genes, that have the same structure, and that pair during meiosis.

linked genes

Genes located close enough together on a chromosome that they tend to be inherited together.

what happens in meiosis I

Homologous chromosomes separate

law of independent assortment

Mendel's second law, stating that different pairs of allele pairs separate independently from one another during gamete formation

what happens in metaphase I

Paired homologous chromosomes (tetrads) line up across the center of the cell

wild-type allele

The non-mutant form of a gene, encoding the normal genetic function. Generally, but not always a dominant allele.

wild-type traits

Traits most commonly found in nature

Cis allele configuration

Two dominant or two recessive alleles are on each chromosome

crossover

a form of genetic recombination that occurs during prophase I of meiosis between homologs

polymorphic gene

a gene that commonly exists as two or more alleles in a population

monomorphic gene

a gene with only one common, wild-type allele

linkage

a phenomenon in which alleles that are located in close proximity to each other on the same chromosome are more likely to be inherited together

euploid

an individual with the appropriate number of chromosomes for their species

Roberta and Bob lost their first child to Tay Sachs, a recessive disease. What is the probability that their next two children will not be affected? a. 6/8 b.9/16 c. 3/4 d. 1/16 e. nada

b. 9/16

Y/y;R/r x Y/y;R/r What is the probability of obtaining Y/Y;R/R offspring? a. 9/16 b. 3/16 c. 1/16 d. 1/4 e. 1/8

c. 1/16

non-homologous chromosomes

chromosomes that contains alleles for different type of genes

Y/y;R/r x Y/y;R/r What is the probability of obtaining Y/y;R/R offspring? a. 9/16 b. 3/16 c. 1/16 d. 1/4 e. 1/8

e. 1/8

zygote

fertilized egg

unlinked genes

genes that are found on different chromosomes

meiosis halves the number of chromosomes to produce _________

haploid gametes

what does meiosis produce

haploid gametes

haploid

having a single set of unpaired chromosomes

crossover happen only on

homologous chromosomes

In a D/d cell, D and d are on: a. homologs b. non-homologous chromosomes c. sister chromatids d. different strands of DNA e. idk

homologs

what happens in anaphase I

homologs segregate away from each other

monohybrid cross

hybridization using a single trait with two alleles (as in Mendel's experiments with garden peas)

monohybrids

individuals having two different alleles for a single trait

aneuploidy can result from

non-disjunction in either the first or second meiotic division

ploidy

number of sets of chromosomes in a cell

Trans allele configuration

one dominant and one recessive allele are on each chromosome

how do you generate a haploid gamete from a diploid cell?

one round of duplication and two rounds of segregation

Law of the product

probability of 2 or more independent events occurring together is the product of the probabilities that each event will occur by itself

law of the sum

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

what happens in metaphase II

sister chromatids line up on the metaphase plate

what happens in anaphase II

sister chromatids segregate away from each other

gamete

specialized cell involved in sexual reproduction

Recombination

the genetic process by which one chromosome breaks off and attaches to another chromosome during reproductive cell division

phenotype

the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.

what would the pattern of inheritance look like for a common recessive trait?

vertical pattern of inheritance