Basic Genetics and Biochemistry Inheritance

Consists of a long DNA molecule that is folded around proteins

Chromosomes

Contains one copy of DNA tightly coiled

One sister chromatid

Contains another copy of DNA

Another sister chromatid

Each unit of chromosomes consists of two _____ ______ _______ joined together at a constricted point.

rod-like structures

DNA and chromosome proteins are called

Chromatin

is the region of the chromosome where chromatids are held together.

Centromere

Chromosomes are classified with respect to the location of centromere

Telocentric, acrocentric, metacentric

An arrangement that provides a picture of the complete set of chromosomes is known as the

Karyotype

is useful in determining the chromosome number of a species.

Karyotype

Karyotype shows the difference in size and banding pattern of the?

Chromosomes

Contains DNA that codes for the same genes

Homologous Chromosomes

is the position or location on a chromosome where a particular gene is found.

Loci

are different forms of the gene that can be found on the same loci.

Alleles

• Genes are different

• Occupies same position in the chromosome

• Have effects on same trait

Alleles

Increase in the number of cells from a single-celled zygote that contains the exact same set of chromosomes as the original single-celled zygote

Mitosis

Chromosomes become visible as extended double structure

Prophase

Chromosome pairs become thicker and shorter

Prometaphase

Nucleus is replaced by spindle, chromosomes become aligned on equator

Metaphase

Chromosome pairs split and move forward opposing poles

Anaphase

Chromosomes reach poles

Telophase

There are two copies (homologous) of each chromosome, one derived from each parent

Diploid Cells

Nuclei reform; each daughter has complete set of chromosomes, one member of each pair derived from each parent

Cytokinesis

Produces four haploid cells after the process, each with own genetic composition which is different from the diploid mother cell.

Meiosis

Haploid reproduction cells (gametes, spores) are the product of ________ _______

meiotic division

What determines the sex of animals?

XX - female

XY - male

contains the SRY gene (sex determining region of the Y chromosome) located on the short arm of the _ chromosome.

Y chromosome

Its presence provides the initial signal for differentiation of the gonads in the embryo to develop into a testis rather than an ovary.

Y chromosome - SRY gene

These are variations in the number of individual chromosomes as well as rearrangements of the genetic material either within or among the chromosome.

Chromosomal Aberrations

with extra chromosome

Trisomy

lacks one chromosome

Monosomy

contains a complete diploid set of chromosomes.

Euploidy

occurs when an organism loses or gains one or more chromosomes.

Aneuploidy

Consists of two strands that wrap around each other to resemble a twisted ladder

DNA

Meaning of DNA

Deoxyribonucleic acid

Each strand is a linear arrangement of repeating similar units called

Nucleotides

Because of the angled spatial arrangements between the sugars, phosphates and bases, the DNA actually _______ ______ _______

spirals around itself

The DNA molecule consists of four different bases:

Purines: Adenine, Guanine

Pyrimidines: Thymine, Cytosine

DNA strands in a double helix MUST have?

matching base pairs

A segment of DNA including all the nucleotides that are transcribed into mRNA is called a

Structural Gene

Replication begins with the?

Separation of the double helix

Replication begins with separation of the double helix. As the strands unwind, nucleotides in the cell pair up with the complementary bases. Synthesis is catalyzed by the enzyme ___ ________

DNA polymerase

the DNA sequence in one of the strands acts as a template for synthesis of RNA

Transcription

In transcription, the DNA sequence in one of the strands acts as a template for synthesis of RNA. Synthesis is catalyzed by the enzyme ___ ________

RNA polymerase

Synthesis of new proteins begins with

transcription