Genetics Quiz

DNA controls everything about an organism.  Explain why using the words DNA, Protein, Enzyme, and body functions.

• Enzymes are proteins that help with body functions. DNA carries the instructions for proteins. 

What are the three parts of a nucleotide?

• Phosphate group, sugar group, nitrogenous base 

Which two parts string the nucleotides together?

• Phosphate group and sugar groupThe phosphate group and sugar group are connected through covalent bonds, forming the backbone of the DNA or RNA strand.

Which part holds the two chains together in the “double helix”?

The base pairsare held together by hydrogen bonds, forming the rungs of the double helix.

Name the four bases (By name)  and the base pairs.

Adenine & Thymine, Cytosine & Guanine 

What is the purpose of DNA replication and what phase of the cell cycle does this happen?

• DNA replication happens in interphase and is to form chromosomes, which is for DNA division and eventually cell replication

Describe in detail the process of DNA replication.

DNA’s double helix uncoils and separates & new complementary strands are made, making a replica of DNA

How many chromosomes does a human have?

23 pairs

Use the words Chromatin, Chromatid, and Centromere to explain how a chromosome forms.

Chromatins make a copy of each other, creating sister chromatids, held together by a centromere, forming a chromosome.

How many amino acids are there?

22

Explain the role that amino acids play in the building of a protein.

Amino acids form in a specific order for a specific protein, just like letters of the alphabet.

Explain the main purpose of Transcription

To make mRNA, a copy of a gene

Where does transcription take place?

A portion of DNA in the nucleus produces a complementary strand of RNA using base-pairing rules, creating mRNA

Explain the main purpose of Translation

Translation is putting the correct amino acid order to build protein

Describe how Translation occurs

• a ribosome binds to a strand of mRNA, or tRNA and brings amino acids into the ribosome. each 

• (rough endoplasmic reticulum ucl, anti codons, strat codons, tRNA, amino acids)

What is the purpose of mRNA?

Instructions for a protein (messenger RNA ,  nucleus to rough endoplasmic reticulum and ribosomes)

How is mRNA different from DNA?

mRNA replaced Thymine with Uracil, different sugar groups (DNA-deoxyribous RNA-ribose), DNA is also in the form of a double helix while mRNA is one chain

Where is mRNA created?

Nucleus

After mRNA is made, what does it do?

Detach from nucleus to endoplasmic reticulum (instructions for protein)

What is the purpose of tRNA?

Transportation of amino acids to ribosomes during translation

Describe the structure of a tRNA molecule.

One end, anti codon (3 bases), other end amino acids, middle part extra stuff.

Explain the role of codons and anticodons in the process of translation

codons are on mRNA, every 3 bases on an mRNA strand, three bases are on tRNA molecule → matches each other for correct amino acid order for translation

Before Mendel, what did people think about how we inherit our traits?

People thought everyone was always an exact mixture of their parents (blending inheritance)

For Mendel’s first experiment what was the P1 generation’s genotype and phenotype?

Homozygous purple and homozygous white. phenotypes are purple and white

For Mendel’s first experiment what was the F1 generation’s genotype and phenotype?

All heterozygous purple offspring

For Mendel’s first experiment what was the F2 generation’s genotype and phenotype?

3 came out purple and 1 came out white. 1 homozygous white, 2 heterozygous purple, 1 homozygous purple

How did this experiment prove his law of segregation?

Results came out to exactly 75% purple and 25% white

What SPECIFIC events occur in Meiosis that ensure the law of segregation happens? Explain HOW it ensures it happens.

Separation of homologous chromosomes in Anaphase 1, sister chromatids separating in Anaphase 2, overall creating 4 unique gametes, each have 1 of every chromosome, ensuring the law of segregation

How did this experiment prove that Dominant and Recessive Alleles exist?

White flowers was a recessive allele because it only showed up in the phenotype if it was homozygous. If there was a purple allele in the flower’s genotype, it would always end up purple because it’s a dominant allele.

For Mendel’s second experiment what was the P1 generation’s genotype and phenotype?

Homozygous dominant (yellow round), and homozygous recessive pea plants (green wrinkled)

For Mendel’s second experiment what was the F1 generation’s genotype and phenotype?

100% yellow and round pea plants

For Mendel’s second experiment what was the F2 generation’s genotype and phenotype?

Came out 75% yellow, 25% green, and 75% round and 25% wrinkled

How did this experiment prove his law of independent assortment?

Proved that what a plant gets for one gene does not influence what it’ll get for another gene because both genes independently followed the law of segregation  

What SPECIFIC events occur in Meiosis that ensure the law of independent assortment happens? Explain HOW it ensures it happens. 

In metaphase 1 the homologous chromosomes are randomly paired up and in anaphase 1 homologous chromosomes are pulled to opposite sides, creating many variations of alleles

What is the purpose of Meiosis?

To create gametes, pass down half of DNA to offspring.

Distinguish between the events that take place during Meiosis I and Meiosis II.  What is the end result of each stage?  Be sure to apply the concepts of Tetrads, Homologous Chromosomes, and Sister Chromatids during these processes and understanding when and how they are involved. (KNOW THE PHASES!!!)

• Meiosis 1: tetrads form in Prophase 1 ->  homologous chromosomes separate in anaphase 1 -------->  end result 2 haploid cells 

• Meiosis 2: sister chromatids separate in anaphase 2,  ---> end result 4 unique haploids 

Explain the difference between Codominance and Incomplete Dominance

Codominance is when both alleles are expressed in the phenotype, while Incomplete Dominance has no dominant alleles and is blended together

How did Morgan prove sex-linked traits?

The fruitflies traits were inherited along with the sex; the recessive white eye allele was carried on the X chromosome, resulting in most males being white-eyed

Explain why polygenic inheritance results in a wide range of phenotypes.

Polygenic when there’s a spectrum of phenotypes

Explain the difference between a Point Mutation and a Frameshift Mutation.

Point mutation is a change in a single nucleotide in the DNA sequence, changing 1 amino acid leaving no affect, while a Frameshift Mutation is the addition or the lack of one or more nucleotides in the DNA sequence, changing many amino acids and altering the protein itself

Explain the difference between a gene mutation and a chromosomal mutation. 

A gene mutation is a change in the DNA sequence of a gene, affecting some nucleotides, while a chromosomal mutation is a change in the structure or amount of chromosomes, affecting multiple genes

Sickle-cell anemia is a genetic disorder that is inherited.  People who inherit this condition have one single base that is incorrect in the gene that produces a very important protein called hemoglobin in red blood cells.  Because that one base is incorrect, one amino acid is incorrect and that screws up the shape of the protein.  Explain how the very first person most likely ended up with the disorder.

To be the first person, a mutation had to happen in the sperm or the egg. The offspring must have reproduced, further spreading the mutation.

Explain what must happen in order for mutations to be passed on to future generations.

People with mutations would reproduce and pass it onto future generations.