Unit 5 Flashcards
Haploid
A cell that only contains 1 chromosome. (n)
Gamete
A sex cell (haploid). Examples include sperm and egg.
Dipold
A cell that has 2 sets of chromosomes. (2n)
Homoglous chromosomes
a pair of chromosomes in a diploid organism that have the same genes in the same order, meaning they are similar in structure and size, with one chromosome coming from the mother and the other from the father.
Gregor Mendel and Mendelian genetics
Gregor Mendel discovered genetics. And Medelian genetics A type of genetic allelle meant the dominant allele was expressed.
Homozygous
They share 2 same alleles.
Heterozygous
Different versions of homoglous chromosomes.
Phenotype
The expressed physical traits.
Genotype
The genetic combination. (Combo of alleles)
Dominant Alleles
Alleles can be dominant or recessive. You can only see the phenotype of the dominant.
P Generation
Paternal generation.
F1 generation
All hybrids; all heterozygous. Offspring of P generation.
F2 generation
Grandchildren of P generation, children of F1 generation. Offspring of a cross between hybrids.
Law of segregation
Allells separate independently during meiosis which allows for a different combination of alleles.
Law of independent assortment
During gamete formation different pairs of alleles segregate independently of eachother. The given allele from your mother or father is completely random and is not effected by the alleles of the other parents.
Monohybrid cross
A genetic cross eximinaing a single trait.
Dihybrid cross
A genetic cross examining 2 traits.
Linked Genes
Genes located close together on the same chromosome tend to be inherited together because they are less likely to be
separated during crossing over in meiosis. This reduces the independent assortment of these genes. It is impossible for linked genes to be on different chromosomes.
Barr Bodies
Barr bodies help determine X chromosome
abnormalities in conditions like Turner syndrome (XO) or
Klinefelter syndrome (XXY)
Co-dominace
When both alleles are expressed at the same time, but do no blend! So there may be white portions of a flower and red portions of a flower.
Complete Dominace
Dominance where the homozygous completely masks the heterozygous and phenotypically look the same.
Sex-Linked genes
Traits and diseases that are more likely to occur in one sex over the other. Mostly sex-linked traits are found on the X chromosome. Which is especialy detrimental to males as they only have one X. Females can be carriers.
Allele
A version of a gene. (i.e purple or white flowers different versions of the color gene.)
Non-Mendelian genetics
A type of genetic inheritance that is more nuanced compared to Mendelian. It includes Co-dominant.
Somatic cell
Any cells other than a reproductive cells.
Asexual reproduction
Asexual reproduction produces clones that are genetically identitcal to the parent. Low genetic variation but efficient. Somatic cell divison to create a new indepdent somatic cell.
Zygote
The result of a fusion of a sperm and egg; a fertilized ovum.
Fertilization
When 2 gametes (haploid) combine to form a zygote (diploid cell).
Meiosis I
Duplicated parts of homoglous chromosomes are separated. Reducing the chromosome number. Meiosis I begins with one diploid parent cell and ends with two haploid daughter cells.
Meiosis II
Starts with 2 haploid parent cells then the duplicated chromosomes are then separated. In the end 4 genetically different gametes are produced.
Chiasmata
The point of contact, the physical link, between two (non-sister) chromatids belonging to homologous chromosomes. Later crossing over occurs.
Nondisjunction
When chromosomes don’t separate correctly in meiosis/mitosis. The result is a extra or missing chromosome.
Autosomal chrosomsomes
Chromosomes 1-22 that are not sex chromosomes.
Centromere
A structure that hold 2 chromatids together. (X)
Sex chromosomes
X and Y! Non autosomal.
Sister Chromatid
A sister chromatid refers to the identical copies formed by the DNA replication of a chromosome, with both copies joined together by a common centromere.
Iocus
Specific location of a gene on a chromosome.
Chromatin
Chromatin refers to a mixture of DNA and proteins that form the chromosomes found in the cells of humans and other higher organisms.
polygenic genes
When 2 or more genes determine a trait.
Pedigrees
tetrad
recombination
Happens during Meiosis I. The order of genes on a chromosome can be determined using recombination frequencies. Pairs of genes with larger recombination frequencies are typically farther apart, while pairs of genes with smaller recombination frequencies are typically closer together.
chiasmata
Incomplete dominance
Red + White = pink flower, both traits are expressed at the same time and blend.
