Chapter 19: Epigenetics/ Genetics

Question 1

What did the human genome project accomplish?

Answer 1

-It was able to read the entire basic consequences of some humans
-It gave us the order of bases and start to understanding human genetics
- Sequence about 3 million bases
Found 20 to 25,000 protein making genes

Question 2

What is the human genome?

Answer 2

The complete set of genetic information in humans

Question 3

We inherit chromosomes in pairs, in a chromosome DNA is wrapped around what? (Remember chromosomes are made of two things, DNA, and ______)

Answer 3

Histones; proteins

Question 4

What is a gene be specific? What two functional molecules (ones that can do work in the cell) can we get from a gene?

Answer 4

A gene is a Piece of DNA real into RNA and or protein

Question 5

Define epigenetics

Answer 5

Chemical tags that attach to DNA or the hisstone proteins that determine gene expression

Question 6

What two places can chemical tags attach to, and thus change gene expression?

Answer 6

DNA and histone proteins

Question 7

Name a few things that can change Epigenetic tags.

Answer 7

Diet, stress, physical activity, exposure to toxins or chemicals ( pollution, smoking), age, drinking, etc

Question 8

What is meant by gene expression

Answer 8

Some genes are turned on and some are turned off

Question 9

What happened in the study with the mother mouse that was fed B vitamins during pregnancy? Did This study show that the Mother’s diet could affect anything ? If so what and how?

Answer 9

Fat yellow Mothers gave birth to thin brown mice no longer prone to disease. Yes, it showed that I could affect the color of the mice, and that they will no longer be prone, two disease and the size.

Question 10

what did the study show with the mother that did not lick and groom (nurture) her Young (What was the difference in the nurtured vs the non-nurtured mice).

Answer 10

That her children showed higher levels of stress, and blood pressure and they are more aggressive , and the ones that were nurtured grew up way differently. The behavior has an impact on genes not just the genes themselves

Question 11

Twins might have identical DNA, but what happens to their epigenetics as they age?

Answer 11

As the years pass epigenetic changes occur, just like the rest of us. Non identical twins

Question 12

What is epigenetic therapy and what is it being used for?

Answer 12

It’s a type of treatment that changes Epigenetic tags to turn genes on or off without changing the DNA sequence and it is mainly used to treat cancer because some cancers happen When important genes are turned off by epigenetic tags. epigenetic therapy Can reactivate those genes or silence Harmful ones so it acts like a reset to help cells behave Normally again. 

Question 13

What is a trans generation response as seen with pesticides in mice? (this is scary)

Answer 13

Transgenerational response means that exposure to a chemical effects not just exposed mice but also their offspring and later generations even though those later generations were never directly exposed

Question 14

what is the human Epigenome project

Answer 14

HEP studies the epigenetic tags to understand how genes are turned on or off in different cells and conditions

Question 15

What can we do with DNA sequencing?

Answer 15

Find ancestors, do paternity test, genetic testing, and forensics

Question 16

Why does epigenetics change even when the genomes don’t?

Answer 16

Bc epigenetic tags respond to the environment, not the DNA sequence itself

Question 17

how is HGP and HEP different from each other?

Answer 17

HGP mapped the genetic code while HEP studied how that code is controlled

Question 18

Does the genome (DNA sequence) ever change? 

Answer 18

It’s stable and rarely changes

Question 19

Can the chemical tags be added or removed from DNA or histones?

Answer 19

Yes (bc these tags can turn on or off without changing the DNA code)

Question 20

What is the human genome

Answer 20

The total complete DNA sequence in our cells

Question 21

How many total chromosomes do we have in each of our body cells? How many pairs does this make?

Answer 21

46
23 pairs

Question 22

Who is Gregor Mendel?

Answer 22

Gregor Mendel was a scientist known as the “father of genetics.”

He discovered the basic rules of inheritance by studying how traits are passed from parents to offspring using pea plants in the 1800s.

Question 23

What is a Chromosome

Answer 23

A long, coiled structure of DNA found in the nucleus that carries many genes.

Question 24

What is a gene

Answer 24

A segment of DNA on a chromosome that codes for a specific trait (like eye color).

Question 25

What is an allele and how many make a gene

Answer 25

A different version of a gene (for example: brown eyes vs. blue eyes)

Question 26

Dominant & Recessive Alleles Definition and how do they intera

Answer 26

Dominant allele: Masks the recessive allele and is expressed when present (capital letter). Recessive allele: Only expressed when two copies are present (lowercase letter).

Question 27

What is a genotype

Answer 27

The genetic makeup of an organism (the letter combination, like BB, Bb, bb).

Question 28

What is a phenotype

Answer 28

The physical trait you can observe, resulting from the genotype (like brown eyes).

Question 29

Describe the alleles of these • Homozygous dominant: • Heterozygous: • Homozygous recessive:i

Answer 29

• Homozygous dominant: Two dominant alleles (BB) • Heterozygous: One dominant and one recessive allele (Bb) • Homozygous recessive: Two recessive alleles (bb)

Question 30

What is a punnett square

Answer 30

A diagram used to predict offspring genotypes and phenotypes from parental alleles.

Question 31

Based on the genotype say the phenotype for dominant brown hair and recessive blonde hair: BB, Bb, & bb

Answer 31

BB → dominant phenotype (brown hair) • Bb → dominant phenotype (brown hair) • bb → recessive phenotype (blonde hair) A dominant allele only needs one copy to be expressed.

Question 32

When is a recessive trait expressed?

Answer 32

A recessive trait is expressed only when both alleles are recessive (bb).

Question 33

Genotypic & Phenotypic Ratios (Bb × Bb)

Answer 33

Genotypic ratio: 1 BB : 2 Bb : 1 bb Phenotypic ratio: 3 dominant : 1 recessive

Question 34

What is X-linked inheritance?

Answer 34

X-linked inheritance occurs when a gene is located on the X chromosome, often affecting males more than females.

Question 35

Why males show X-linked recessive traits more often

Answer 35

Males have only one X chromosome, so one recessive allele is enough to express the trait. Females need two recessive alleles.

Question 36

What is an Example of X-linked traits

Answer 36

• Red–green color blindness • Hemophilia • Duchenne muscular dystrophy

Question 37

X-linked offspring ratios (carrier mother × normal father)

Answer 37

• Females: 50% carriers, 50% unaffected • Males: 50% affected, 50% unaffected

Question 38

A red fish and a yellow fish mated and produced offspring that were orange in color, which is a mixing or intermediate of both red and yellow. What pattern of inheritance does this best represent? A. x-linked​ B. incomplete dominance​ C. dominant-recessive​ D. codominance

Answer 38

B. incomplete dominance​

Question 39

How many alleles do humans have per gene?

Answer 39

2