Principles of Genetics

What are the stages of Mitosis?

Interphase, Prophase, Metaphase, Anaphase, Telophase/Cytokinesis

What is Interphase?

The initial stage of the cell cycle where the cell spends the most amount of time in this phase growing for miotic division

What are Chromosomes?

It is where the DNA is usually located in organized structures

What is a chromatin?

They are unwound chromosome located in the nucleus is replicated

What is prophase?

It is where the chromosomes coil up and condense and where centrioles divide and move apart and it is the longest phase of mitosis

What do centrioles do?

They migrate to opposite ends of the cell to establish poles

What are Sister chromatids?

They are genetically identical chromosomes

What does a centromere do?

They hold the sister chromatids together

What is Metaphase?

It is where Centromeres align on the metaphase plate

What is the Metaphase plate?

It is where the chromosomes line up at the middle of the cell

What do spindle fibers do?

They produce the centrioles attach to the chromosomes at the centromere

What are spindle fibers?

They pull chromosomes apart at the centromeres

What is Anaphase?

It is where Centromeres split and daughter chromosomes migrate to opposite poles

What is Telophase ?

It is where the Daughter chromosomes arrive at the poles and cytokinesis commences, and 2 new identical daughter cells are formed

What is Cytokinesis?

It divides the cytoplasm of the cells into two

What is a gamete?

It is where Meiosis occurs to produce daughter cells with half the numbers of chromosomes as usual

What is Prophase 1?

It is the first and longest phase of meiosis I, during which homologous chromosomes condense and pair up to form tetrads

What is a Tetrad?

It is the forming of two pairs of sister chromatids

What is Prophase 1- crossing over?

It is where a Homologous pair of chromosomes come together in a process called synapsis

What is a Homologous?

It is a pair of chromosomes that come together during Prophase 1-crossing over phase

What is Metaphase 1?

It is where Homologous pairs of chromosomes line up at the middle of the cell in their tetrad and where the spindle fibers attach to the centromere

What is Anaphase 1?

It is where the Homologous chromosomes that formed the tetrad are pulled to the opposite poles it is also where the sister chromatids do not separate at the centromeres

What is Telophase 1?

It is where the cells divides into 2 through cytokinesis, resulting in the completion of the first division or Meiosis 1 it is also the end of meiosis 1 resulting in 2 cells with the same number of chromosomes as the parents

What is Prophase 2?

It is where the centrioles double and the spindle fibers form but nothing has been replicated

What is Metaphase 2?

It is where the Chromosomes line up at the middle along the metaphase plate

What is Anaphase 2?

It is where individual chromatids are pulled towards opposite poles separating at the centromere

What is Telophase 2?

It is where the cells cleave down the middle resulting in a total of 4 daughter cells

What happens at the end of Meiosis?

Four genetically unique daughter cells or gametes that contain only half the number of chromosomes as the original cell

Where does Mitosis occur?

It occurs in the body cells

Where does Meiosis occur?

It occurs in the testes & ovaries

What is True-breeding?

Parents that offsprings are identical form a certain traits

What is an F1 generation?

The First Filial

What is an F2 Generation?

Second filial

What is Reciprocal Cross-breeding?

It is experiment designed to test the role of sex on the inheritance pattern

What is a Gene?

Its the modern term for Mendel’s “unit factors” of unit inheritance

What is an Allele?

Its an alternative form of a gene

What is a Genotype?

Its the genetic makeup of an individual created by the pairs of unit factors or genes

What is a Phenotype?

The physical expression of the trait

What does the term Dominant mean ?

Its where the allele masks or overrides the phenotype of the other allele

What does the term recessive mean?

Its where the allele is masked by the presence of the dominant allele

What does the term Homozygous mean?

It means where both alleles are the same for an individual

What does the term Heterozygous mean?

It mean the alleles are different and there is one dominant allele and one recessive allele

What does test cross mean?

Its where you take an individual with an unknown genotype and crossing it with a known genotype

What does Partial Dominance mean?

Its when a cross between two parents with different phenotypes produces and intermediate phenotype where neither parental allele is dominant

What does Codominance mean?

its where there is a joint expression of both alleles, there is NO blending

What is Sex limited inheritance?

It occurs on autosomal genes, NOT the sex chromosomes its also where the expression of the gene is “turned off” in one of the sexes despite having the same genotype

What are Sex influenced inheritance?

It occurs on autosomal chromosomes, NOT the sex chromosomes its also where the expression of the gene in sex influenced traits is influenced by a hormonal or anatomical difference between sexes

What are Sex limited traits?

Neck plumage in chickens, milk production in cattle, breads/facial hair

What is Nondisjunction?

Its the failure of paired homologous chromosomes to separate during the first meiotic division results in both trisomy and monosomy

What is chromosomal disorder?

a genetic condition caused by a change in the number or structure of a person's chromosomes, which are structures in cells containing genetic information