Gr 11 Bio Unit 2 Test - Genetics

Hybrid

The offspring of two plants or animals with different versions of the same trait, causes the presence of hetrozygous traits.

Monohybrid

A genetic cross or hybrid involving a single trait or gene with two contrasting alleles.

Coding DNA

The specific portions of the genome that contain instructions for synthesizing proteins. Makes up about 2% of the human genome.

Non-coding DNA

Sequences of DNA that do not encode protein sequences. Makes up 98% of the human genome.

Dominant

An allele that expresses its phenotypic trait even when present in a single copy (heterozygous).

Recessive

An allele whose phenotypic effect is masked in heterozygotes and is only expressed when two identical copies are present.

Law of Dominance

States that any time a dominant allele is present it will be expressed while masking the recessive allele.

Recombinant DNA

DNA molecules formed through laboratory methods of genetic recombination to combine genetic material from multiple sources.

Genes

Basic units of heredity made of DNA sequences that code for specific proteins.

Alleles

A version of a gene.

Homozygous

A genotype in which the alleles of a gene are the same.

Heterozygous

A genotype in which the alleles of a gene are different.

Punnett square

A tool used by geneticists to predict what the genotypes of a particular cross will be.

Genotype

Refers to the alleles an organism contains for a particular trait.

Phenotype

Refers to observable traits.

Gamete

A sex cell. Sperm for males. Egg for females.

Transcription

The process through which the information on a DNA strand is copied into a mRNA molecule.

Incomplete dominance

A situation where neither allele dominates the other and results in the partial expression of both traits. Has a third phenotype.

Co-dominance

A situation where both alleles are expressed fully. Has a third phenotype.

Interphase

The active phase of the cell cycle where a cell grows, replicates its DNA, and prepares for cellular division.

Tetrad

A group of four closely associated chromatids of a homologous pair formed during prophase I of meiosis.

Metaphase

A stage of mitosis or meiosis where chromosomes align along the equator of the cell.

Prophase

The initial stage of cell division where chromatin condenses into visible chromosomes and the nuclear membrane disappears.

Anaphase

The stage where sister chromatids or homologous chromosomes are pulled apart toward opposite poles of the cell.

Telophase

The final stage where chromosomes arrive at opposite poles, nuclear membranes reform, and chromosomes begin to unwind.

Cytokinesis

The physical division of the cytoplasm that separates a single cell into two (or 4 if done in meiosis II) distinct daughter cells.

Mitosis

A type of cell division that results in two genetically identical diploid daughter cells for growth, repair, and certain types of asexual reproduction.

Chromosomes

Thread-like structures composed of DNA and proteins that carry genetic information.

Sister chromatids

Two identical copies of a single chromosome connected by a centromere, formed during DNA replication.

Translation

The process where ribosomes synthesize proteins by decoding the genetic code carried by mRNA.

Daughter cells

The new cells formed resulting from the division of a single parent cell.

Mutations

Variations in DNA caused by misspelling or misinterpretations of codons. Can help speed up evolution or, more likely, cause diseases or disorders.

Meiosis

Cell division that produces 4 haploid daughter cells. These cells are sex cells.

Haploid

Having a single set of unpaired chromosomes. Gametes.

Diploid

Containing two complete sets of chromosomes, one inherited from each parent. Somatic cells.

Autosome

Any chromosome that is not a sex chromosome (chromosomes 1 through 22 in humans).

Sex chromosome

A chromosome involved in determining the biological sex of an organism, such as the X and Y chromosomes in humans.

Homologous chromosome

A pair of chromosomes of the same length and traits with one inherited from each parent.

Centromere

The specialized region of a chromosome where two sister chromatids are joined and spindle fibers attach during division.

Crossing over

The exchange of genetic material between non-sister chromatids of homologous chromosomes during prophase I, increasing genetic diversity.

Spermatogenesis

The process of producing sperm cells through meiosis in males.

Oogenesis

The process of producing egg cells through meiosis in females.

Nondisjunction

The failure of homologous chromosomes or sister chromatids to separate properly during cell division.

Trisomy

A chromosomal abnormality characterized by the presence of an extra chromosome, resulting in three instead of a pair.

Monosomy

A chromosomal condition characterized by the absence of one member of a chromosome pair, resulting in a single chromosome.

DNA

Deoxyribonucleic acid, the double-helix molecule that carries genetic instructions for all living organisms.

Adenine

A purine nitrogenous base in DNA and RNA that pairs specifically with thymine (in DNA) or uracil (in RNA).

Thymine

A pyrimidine nitrogenous base found exclusively in DNA that pairs specifically with adenine.

Guanine

A purine nitrogenous base in DNA and RNA that pairs specifically with cytosine.

Cytosine

A pyrimidine nitrogenous base in DNA and RNA that pairs specifically with guanine.

Purines

Nitrogenous bases which includes adenine and guanine.

Pyrimidines

Nitrogenous bases which includes thymine and cytosine.

Codon

A sequence of three consecutive nucleotides in mRNA that specifies a particular amino acid or stop signal.

DNA replication

The process of producing two identical replicas of DNA from one original DNA molecule.

Karyotype

A picture of an individual's complete set of chromosomes, organized and displayed by size, shape, and banding pattern.

Actionable gene

A gene where identified variants have established clinical interventions, treatments, or preventive measures available.

Whole Genome Sequencing

A method that determines the complete DNA sequence of an organism's entire genome.

DNA Bank

A repository where DNA is stored for research, medical, or forensic applications.

Gene therapy

An experimental technique that uses genetic material to treat or prevent diseases by correcting defective genes inside a patient's cells.

Carrier

An individual who inherits one copy of a recessive mutant allele and one normal allele, typically showing no symptoms but able to pass the trait on.

Genotyping

The process of determining specific variations in an individual's DNA sequence across their genome by only looking at certain areas of their genome.

Sex-linked inheritance

The transmission of genes located on sex chromosomes, leading to distinct inheritance patterns between males and females.

Describe DNA structure

DNA is structured as a double-helix made of repeating nucleotide units (sugar-phosphate backbones and nitrogenous bases: Adenine, Thymine, Guanine, Cytosine).

Details of the DNA’s discovery (1953 only date required)

• Friedrich Miescher discovered nuclein.

• Phoebus Levene determined the different parts of DNA.

• Joachim Hammerling determined the nucleus contained genetic material.

• Erwin Chargaff determined the base pairings for the bases.

• Rosalind Franklin and Maurice Wilkens took Photo-51.

• Alfred Hershey and Martha Chase determined DNA was the transforming principal.

• In 1953, James Watson, Fancis Crick, and Maurice Wilkins won the Nobel Prize for their structure of DNA.

Describe what is happening at each stage of mitosis

Mitosis consists of Prophase (chromosomes condense, nuclear envelope breaks down), Metaphase (chromosomes align at the equator), Anaphase (sister chromatids pull apart), and Telophase (two new nuclei reform), concluding with cytokinesis.

Describe what is happening at each stage of meiosis I

Describe what is happening at each stage of meiosis II

Compare and contrast mitosis and meiosis

Describe the process of protein synthesis (steps involved in transcription and translation)

Uses of Canada’s DNA data bank in law enforcement

Uses of recombinant DNA in food production / pest resistance

Obstacles of gene therapy

Difference between whole genome sequencing and genotyping

Explain sex-linked inheritance and relative prevalence in males and females

What abnormalities can be identified using a karyotype?

1. Klinefelter syndrome

2. Edwards syndrome

3. Turner’s syndrome

4. Patau syndrome

5. Down syndrome

Klinefelter syndrome

Edwards syndrome

Turner’s syndrome

Patau syndrome

Down syndrome