Grade 10 - Genetics

Question 1

Define DNA

like what is its purpose in life

Answer 1

DNA (deoxyribonucleic acid) is the genetic blueprints for every living being. It determines your attributes, e.g physical appearance, physiology, a little affect on personality

Question 2

What are the 4 Nitrogen bases found in DNA?

Answer 2

Adenine, Thymine, Cytosine, Guanine
Each only bonds with one of the other bases
Adenine + Thymine, Cytosine + Guanine
Apples go under Trees, Cars go in the Garage

Question 3

Where is DNA found in Eukaryotes?

Eukaryotes are organisms that have cells with a nucleus e.g animals, plants

Answer 3

In Eukaryotes, the DNA is found largely in the Nucleus, but also the mitochondria, and in the case of plants, chloroplasts.

Question 4

Where is DNA found in Prokaryotes?

Prokaryotes are organisms that have cells without a nucleus e.g bacteria

Answer 4

In Prokaryotes, the DNA is found in the Cytoplasm

Question 5

What is DNA made of?

Answer 5

DNA consists of many smaller building blocks - nucleotides - that are each composed of a Sugar (Deoxyribose), Phosphate and a Nitrogen Base.This is all built in a double helix form. DNA is also anti-parallel, meaning one side is upside down.

you can search up simple nucleotide structure to see what it looks like

Question 6

How does DNA determine the attributes of an organism?

Answer 6

DNA determines the attributes through the sequence of the nitrogen bases, with the only difference between organisms and species being the sequence of the DNA

Question 7

How does DNA replication happen?

Answer 7

DNA replication first starts with a section of the DNA splitting in 2. Then, each side is copied and pasted1, and the newly formed copy bonds with the old copy, forming 2 new strands of DNA. Each strand has one half of the original, and one half new copy

1 Not really, an enzyme just brings in nucleotides with the corresponding nitrogen base to the ones that are attached to the original strand

Question 8

What is the enzyme that splits the DNA in replication called?

Answer 8

The enzyme Helicase “unzips” the DNA

Question 9

What is the enzyme that brings in the nucleotides called?

Answer 9

The enzyme “polymerase” brings in nucleotides to form the new DNA section

Question 10

When does DNA Replication occur?

Answer 10

During the S-Phase of interphase in the cell cycle

Question 11

Define Gene

Answer 11

Genes are sections of DNA that are code for a specific heritable characteristic

Question 12

Define Allele

Answer 12

An allele is a specific form of a gene (such as dominant or recessive), differing from other alleles in the same gene by a few nitrogen bases, while also occupying the same locus (location)

Basically, the different options that a gene could be, e.g blonde hair is one allele, and brown hair is another allele, with hair color being the gene

Question 13

Define Genome

Answer 13

All of the genetic information of an organism

Question 14

Define gene pool

Answer 14

All of the genes possible in a population

Question 15

Define gene mutation

Answer 15

A gene mutation is a random change in DNA, which usually occur when cells are making copies of DNA for cell division. It can only be passed on to offspring if the mutation occurs within sex cells

Question 16

Define karyotype

Answer 16

A photograph of chromosome pairs

Question 17

What are chromosomes made of?

Answer 17

Chromosomes are proteins which are wrapped in DNA

Question 18

What is RNA and how is it different from DNA

Answer 18

RNA (ribonucleic acid) is a nucleic acid, like DNA. However, it only has one strand instead of 2, the nitrogen base thymine is replaced with uracil, meaning that A bonds with U instead of T, and the sugar is ribose instead of deoxyribose

Question 19

What are the 3 versions of RNA

Answer 19

mRNA - Messenger RNA
rRNA - Ribosomal RNA
tRNA - Transfer RNA

Question 20

What is the function of mRNA?

Answer 20

mRNA copies the sequence of the nitrogen bases, or the code, from the DNA in the Nucleus and carries it to the ribosomes. 3 consecutive nitrogen bases on an mRNA strand is called a codon

Question 21

What is the function of rRNA?

Answer 21

It makes up the ribosome (surprise surprise), and it is located in the cytoplasm and on the rough ER (its an organelle in the cell, we learned about it last year but i dont think we need to know anything about it)

Question 22

What is the function of tRNA?

Answer 22

The tRNA travels to the ribosomes to transfer amino acids. It knows what amino acids to bring by having a matching anticodon to each codon in the mRNA. You can find out what amino acid matches to what codon by checking the codon chart, the circle thingy we used in class

Question 23

What is the purpose of all 3 RNAs?

Answer 23

To make proteins, which is necessary to carry out all metabolic functions. Proteins are made up of amino acids.

Question 24

What are the 2 steps in protein synthesis?

Protein Synthesis = Making proteins

Answer 24

1. Transcription - Making RNA
   - mRNA is made by copying the nitrogen base sequence from DNA in the nucleus, where it then leaves the nucleus to the cytoplasm
2. Translation - Making proteins
   - tRNA copies the codons from the mRNA, and transfers the matching amino acids to the ribosomes, where they are assembled into proteins

The slides have some great images showing this

Question 25

How are Proteins synthesized?

Answer 25

• Amino acids are assembled in a specific sequence, according to the information from the mRNA
• There are 20 amino acids, and 64 codons, meaning some amino acids have more than 1 codon
• All protein synthesis begins with a start codon, which is AUG. The amino acid for this codon is methionine
• There are multiple stop codons, including UAA, UAG & UGA
• The stop codons just tell the ribosome that the protein is done and can be released

Question 26

What is Mendelian Genetics?

Answer 26

Mendelian Genetics is the conclusion gathered by Gregor Mendel. These include:
1. Heredity consists of various factors, now called genes, that are passed from parent to child
2. Both parents contribute 2 copies of a gene each, but only one of the is inherited, and the one chosen is random 1
3. Some alleles are dominant, and some are recessive. The dominant prevent the recessive from being expressed in the organism

1 Each parent gives 2 genes because they also had 2 parents

Question 27

Define dominant and recessive alleles

Answer 27

Dominant Alleles are represented through a capital letter, and while always be expressed if they are present in the gene

Recessive Alleles are represented through a lowercase letter and will only be expressed if there are no dominant genes

Question 28

Define homozygous and heterozygous

in terms of alleles

Answer 28

Homozygous, or purebred, means the organism inherited the same allele from each parent (TT or tt)

Heterozygous, or hybrid, means that the organism inherited one dominant and one recessive gene (Tt)

i cant come up with a gay joke for this im sorry

Question 29

Define genotype and phenotype

Answer 29

Genotype is the genetic makeup of an organism, being represented with letters (TT, Tt or tt)

Phenotype is the genotype when it physically expressed, e.g tall or short, green or yellow blablabla

Question 30

What are Punett Squares?

Answer 30

Punett squares are methods of determining the possible genotypes of an offspring of 2 organisms.
The columns represent one parents allele, and the rows the other’s. Where the individual letters intersect, they combine to show one possibility for the offspring’s allele.
Each individual box has the same 1 in 4 chance of being the allele of the offspring, however multiple boxes in a punett square can have the same allele.

I cant really help yall revise these youll just have to look at the worksheets we did or something