DNA Structures and Genetics

Question 1

What is DNA?

Answer 1

DNA stands for , Deoxyribonucleic acid. DNA is a molecule found in every cell in every living and non living organisms. For example, any animal or human carries DNA and can be found in viruses. It plays as the instructions to make everything for a cells function.

Question 2

How is DNA stored?

Answer 2

DNA is stored in chromatin. Chromatin is a substance found in all cells and is made out of DNA and proteins. When chromatin is replicated, it can be folded even more into chromosomes. (LOOK AT POWERPOINT TO SEE VISUAL REPRESENTATION)

Question 3

What are the 2 structural components of DNA?

Answer 3

Sugar and Phosphate groups.
Sugar - 5 carbon sugars called DEOXYRIBOSE
Phosphate Groups - A negatively charged group bound to the sugar
These group binds together and alternate form the “DNA backbone”

Question 4

What are the 2 base pairings? (4)

Answer 4

These are called complementary base pairings, singles go with doubles and so forth.
Thymine (T) - Adenine (A)
Cytosine (C) - Guanine (G)

Question 5

What forms the Nucleotide?

Answer 5

In the DNA molecule, each base will bond to a sugar group and has a phosphate group bound on its other side. The three groupings together consist of (Sugar, Phosphate & Base), they form a nucleotide.

Question 6

What are the “Strands” and “Helix” of DNA?

Answer 6

Strands - Made of 2 strands of nucleotides connected together through base pairings
Helix - DNA shaped as double stranded helix (by twisting)

Question 7

What are genetics?

Answer 7

Genetics in simple terms, the passing of genes from the parents to offspring. Genetics starts with chromosomes which are made out of DNA. These DNA cells in each person are what makes everyone different from one another. KEY TERM = Heredity

Question 8

What was Mendel’s pea plant experiment?

Answer 8

Mendel purposefully cross- pollinated pea plants in order to see how different traits of plants would react to others and what the result of the offspring. He self brushed the pollen from the female part (Pistil) with the male part (Stamen).

Question 9

What are Genes?

Answer 9

Genes are DNA that is passed down from parent to offspring.

Question 10

What is an Allele?

Answer 10

An allele is a possible version of a gene that is described in a code. It can describe the eye color and trait of a person.

Question 11

What is a Phenotype?

Answer 11

Phenotype - the appearance of the particular characteristic, ie. Purple eyes, Blue hair. Overall, a description in words.

Question 12

What is a Genotype?

Answer 12

Genotype - There are 3 types, HOMOZYGOUS DOMINAINT/RECESSIVE and HETEROZYGOUS. When the alleles are = HD is OO, HE is oo and HET is Oo. The genetic code for the persons genes.

Question 13

What is the difference between Complete, Incomplete and Codominance?

Answer 13

Complete : All are dominant or recessive, the dominant trait will over power recessive
Incomplete : A purebred of traits like a mixture, will take on BOTH genes and hybrid
Co-Dominance : The mixture will both be dominant
FOR EXAMPLE :
CO : RT then R is the dominant
INCOM : RT then RT will mix
CODOM : RT will take turns

Question 14

What does Purebred and Hybrid mean?

Answer 14

Purebred : consists of gene pairs with genes that are the SAME (Homozygous)
Hybrid : consists of gene pairs that are DIFFERENT.
(Heterozygous)

Question 15

How many homologous pairs do we have?

Answer 15

23 pairs, 46 total

Question 16

What are the Female and Male sex chromosomes differences.

Answer 16

Female = XX
Male = XY

Question 17

What is Hemophilia?

Answer 17

A RECESSIVE sex linked disorder that affects the body’s ability to make blood clots.

Question 18

How does DNA move from the nucleus?

Answer 18

DNA is stored in the nucleus but it cannot just leave the nucleus. An RNA messenger is produced from DNA and that messenger will take information from the DNA and leave the nucleus.

Question 19

How is RNA different from DNA?

Answer 19

RNA is single stranded, contains Uracil and sugar ribose.
DNA is double stranded, contains Thymine and deoxyribose.

Question 20

How is the Messenger RNA relate to Protein?

Answer 20

The ribosome will read the genetic code on the messenger RNA to will go into 3 codon groups. Then, Amino acids conjoin and link in order to create protein.

Question 21

What are the two types of mutations?

Answer 21

Chromosomal Mutations - whole chromosomes can be added and deleted.
Gene Mutations (MAIN) - affects 1 gene ONLY and often caused by the change of one nucleotide.

Question 22

What are the 3 ways gene mutations can occur?

Answer 22

Addition, Deletion and Substitution

Question 23

What are the differences between ADDITION DELETION AND SUBSITITUTION?

Answer 23

ADDITION - One base is added
DELETION - One base pairing is removed
SUBSTITUTION - One base pairing is substituted for another pass pairing

Question 24

What are the 3 effects of Mutations?

Answer 24

Positive effect - can create a positive change for the organism to survive and reproduce
Negative effect - decreases the chances of survival
Neutral effect - no effect

Question 25

What were the 3 types of Mutagens?

Answer 25

Physical - radiation damage
Chemical - possible smoke or damage to organisms from such air pollution
Biological - infectious diseases

Question 26

What is Evolution in simple terms?

Answer 26

Evolution is when a change occurs in a species overtime.

Question 27

What is Natural Selection?

Answer 27

Natural selection is a mechanism of evolution. It is a process in nature where the best organism in the environment will successfully survive and reproduce.

Question 28

What is High and Low Fitness?

Answer 28

High - Organism with high fitness are more likely to pass on its alleles to the next generation
Low - Organisms with low fitness are less likely to pass on its alleles to the next generation

Question 29

What is a biological adaptation?

Answer 29

A biological adaptation is a characteristic of an organism that increases it’s fitness. Can be passed down to future offspring.

Question 30

What is Artificial Selection?

Answer 30

Artificial selection is the intentional reproduction of individuals by breeding organisms that have favorable characteristics.

Question 31

What are the requirements for Natural Selection?

Answer 31

Heredity - traits that can be passed on.
Variation in traits - varying levels of fitness.

Question 32

What are Purines and Pyrimidines?

Answer 32

Purines - Double stranded (Guanine and Adenine)
Pyrimidines - Single stranded (Thymine and Cytosine)

Question 33

What were Gregor Mendel’s hypotheses? (4)

Answer 33

1. There are elements that are passed on from parent to offspring
2. Different elements control different traits
3. Elements remain unchanged during the life of the organism
4. Elements are passed in the gametes (egg/sperm) of organisms

Question 34

What was Gregor Mendels “Artificial pollination”? Through generations?

Answer 34

For the first generation, Mendel brushed the pollination from one plant to another in order to create an artificial offspring. Also known as the female Pistil and the male Stamen. As for the second, he allowed them to self pollinate to see which genes would transfer from the first generation.

Question 35

What is Mutagen?

Answer 35

Mutagens are able to cause mutations to occur.

Question 36

What are the effects of Mutations?

Answer 36

Mutations aren’t very useful because they normally have a negative or unnoticeable effect. Mutations are the source of new traits and new alleles that result in genetic diversity.