Genetics Inheritence

Question 1

What are chromosomes?

Answer 1

Structures within a cell nucleus that contain DNA (genetic information)

Question 2

What is a gene?

Answer 2

A specific sequence of DNA. They code for a specific protein or RNA.

Question 3

What are gene variants/alleles?

Answer 3

They have different DNA sequences than the ‘normal’ gene

Question 4

What is genetics?

Answer 4

The study of genes, genetic variation, and heredity

Question 5

What is heredity?

Answer 5

The transmission of traits from one generation to the next

Question 6

Why is Gregor Mendel the father of genetics?

Answer 6

He was the first person to experimentally analyse patterns of inheritance using pea plants as his model system in 1866

Question 7

What is a model system?

Answer 7

An organism that makes it easy for a researcher to investigate a particular scientific question
They then apply their findings to harder to study organisms

Question 8

What is the blending model of inhertiance?

Answer 8

Inheritance involved the permanent blending of parents’ characteristics in their offspring

Question 9

Why was the blending model full of holes?

Answer 9

Could not explain why when Mendel crossed a pure bred tall and short pea plant, he only got pea plants
Also could not explain why self fertilisation of the above tall plants would produce a 3;1 ratio of tall to short plants

Question 10

What does true breeding mean in terms of mendelian genetics?

Answer 10

An organism must be homozygous for every trait for which it is considered true breeding

Question 11

How are peas cross-pollinated and self pollinated?

Answer 11

Cross: Transfer pollen with brush then remove anthers
Self: Transfer own pollen to own stigma

Question 12

Which traits of pea plants did mendel observe?

Answer 12

Format: Trait - Dom trait vs Rec trait
Colour - Purple vs white
Position - Axial vs terminal
Seed Colour - Yellow vs Green
Seed Shape - Round vs Wrinkled
Pod Shape - Inflated vs Constricted
Pod Colour - Green vs Yellow
Stem Length - Tall vs Dwarf

Question 13

What are hybrids?

Answer 13

The offspring of two different purebred varieties

Question 14

How did Mendel determine the flower trait colour dominancy?

Answer 14

P Generation was with purebred white and purp
F1 generation was all power
F2 generation was 3:1 purple to white

Question 15

What is the difference between phenotype and genotype?

Answer 15

Phenotype is what we see

Genotype is the actual allele distribution

Question 16

What are Mendel’s 4 hypotheses?

Answer 16

1. The alternative versions of genes are called alleles
2. For each trait, an organism inherits two alleles, one from each parent. This organism is now diploid (remember gametes are haploid)
3. If 2 alleles differ, only the dominant allele determines the phenotype
4. 2 alleles in a diploid parent separate from each other so that their gametes only have one allele (haploid)

Question 17

What is a Punnet Square?

Answer 17

A diagram used to predict outcomes of a cross breeding. It shows the combinations of gametes and the possible resulting offspring

Question 18

What is complete dominance?

Answer 18

If this allele is present, it will display it’s phenotype over the recessive gene

Question 19

How does genes relate to cystic fibrosis?

Answer 19

CF is a recessive genetic disorder. the C allele produces a normal function CFTR gene. A person with Cc is a carrier. A person with cc has CF, and both parents must have been carriers or have CF.

Question 20

What is incomplete dominance?

Answer 20

Heterozygotes have an intermediate appearance between the two parents
An example would be snapdragon flower colour (RR = red, rr = white, Rr = pink)

Question 21

What is co-dominance?

Answer 21

Both alleles are expressed in a heterozygous individual

An example would be blood cells (AA = A, BB = B, AB = AB)

Question 22

If you receive incompatible blood, _____ occurs

Answer 22

clumping

For example, people of A has Anti B antibodies, meaning any B blood would clump (B/AB)

Question 23

Describe the genetic makeup of bacteria vs eukaryotes

Answer 23

Bacteria: 1 circular chromosome, compact genome, no meiosis, exchange genetic material through conjugation, transformation, and transduction
eukaryotes: Often diploid, large genomes, meiosis, genes change though meiosis and fertilization

Question 24

What are plasmids?

Answer 24

Small circular pieces of DNA

Question 25

How do plasmids and bacteria relate?

Answer 25

Bacteria can have 1 or more plasmids that can insert themselves into the chromosome genome

Question 26

Bacteria usually replicate via _______ ____________

Answer 26

asexual reproduction

Question 27

What is binary fission?

Answer 27

When one bacteria divides into 2 identical daughters. Each daughter receives the exact same copy of circular chromosome and plasmids unless a mutation occurred

Question 28

How can bacterial DNA change via external DNA?

Answer 28

Conjugation - Between a recipient and donor cell
Transformation - Update of naked DNA from the environment
Transduction - DNA transfer between bacteria using a viral vector

Question 29

How does bacterial conjugation work?

Answer 29

The donor cell forms a pilus that connects to the recipient cell. Then a copy of part or all of the donor’s plasmid (and/or part of the chromosome) is transferred to the recipient

Question 30

In bacterial transformation, where can the naked DNA go?

Answer 30

Inserted into the chromosome/plasmid, or it may create a new plasmid

Question 31

What is antimicrobial resistance? Why is it bad?

Answer 31

When a bacteria, virus, fungi, or parasite change over time and no longer responds to medicines.
Increase likelihood of death and disability, prolonged illness, and longer hospital stays
Promotes the need for more expensive medicines and increases healthcare costs

Question 32

How do bacteria develop AMR?

Answer 32

Artificial selection through mutation that provide antibiotic resistance for bacteria expose to antibiotics
Update of resistive genes from other bacteria or the environment (conjugation and transformation)