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
