Unit 6 Study Guide

Question 1

What does the word gen in genetic refer to?

Answer 1

Beginning

Question 2

What’s a trait?

Answer 2

A genetically determined characteristic

Question 3

Give the three subfields of genetics

Answer 3

• classical genetics
• molecular genetics
• population genetics

Question 4

Define “animal husbandry”

Answer 4

Selective breeding

Question 5

Who discovered the probabilistic nature of inheritance?

Answer 5

Gregor Mendel

Question 6

What phase are cells most commonly in

Answer 6

Interphase

Question 7

What happens during G1 phase and s phase and G2 phase?

Answer 7

G1 phase- “ growth” this is where the cell grows up after being made
S Phase- “synthesis” this is where the cell replicates its DNA
G2 phase- “growth” this is when the cell gets ready to split.

Question 8

What is mitosis?

Answer 8

A cell creates more cells by the process of mitosis.

Question 9

What are the four stages of mitosis?

Answer 9

Prophase- this is when the chromosomes condense into their familiar x shapes
Metaphase- this is when the chromosomes line up in the middle of the cell before splitting
Anaphase- this is when the chromosomes are split and in transit across the cell the opposite ends
Telophase- this is when the chromosomes are totally split and in position

Question 10

What is neat about stem cells?

Answer 10

These cells are able to make several types of cells.

Question 11

What is the G naught phase?

Answer 11

A phase when some cells once made do not ever split again.

Question 12

Meiosis is the process of making cells called__________

Answer 12

“gametes”

Question 13

What is a gamete

Answer 13

The cells which are shared during sex, sperm and egg

Question 14

What process results in creation of gametes?

Answer 14

Meiosis

Question 15

What is fertilization

Answer 15

The moment when the sperm and the egg meet.

Question 16

What is a zygote? What is an embryo?

Answer 16

Embryo- two gametes together create an embryo
Zygote- The embryo becomes a zygote in this first stage

Question 17

What is a blastocyst?

Answer 17

A ball of cells that forms early in a pregnancy

Question 18

What is a fetus?

Answer 18

An unborn baby that develops from an embryo (after a blastocyst (

Question 19

What is a gene

Answer 19

Region of DNA that tells the body how to make a protein

Question 20

What’s an allele?

Answer 20

A version of a gene, it’s one of several possible forms a specific Gene can take
Example: having different colored eyes wear blue eye allele and brown eye allele, are the variations of the same gene that’s besides eye color

Question 21

Give the three principles of inheritance discovered by Gregor Mendel

Answer 21

-Unit factors
-Dominance/recessive
-Segregation

Question 22

Distinguish between genotype and phenotype

Answer 22

Genotype- genes behind the scenes ex. Tt
Phenotype- what you can see
Ex. Blue eyes brown hair

Question 23

What is genetic segregation?

Answer 23

When a cell from a parent divides to create gametes, it randomly separates its pair of genes, so each gamete only gets one copy of each gene ensuring a mix of traits

Question 24

Name three exceptions to Mendel’s principles

Answer 24

• Codominance- when both genes show up
• incomplete dominance -(neither allele is fully dominant)
• multiple alleles - when more than two alleles exist for a gene in a population

Question 25

What’s an autosomal Chromosome?

Answer 25

Any of the first 22 chromosomes that are blueprints for almost your entire body

Question 26

Xx versus XY chromosomes

Answer 26

Xx - female
Xy - male

Question 27

What are some chromosomal abnormalities of the sex chromosomes

Answer 27

X- Turner syndrome
XXY- Klinefelter syndrome
XYY- Jakob syndrome

Question 28

If any chromosomes are missing, the result is death. If almost any of these is tripled, the result is death. There are three abnormalities where life lasts past birth:

Answer 28

Trisomy 21- down syndrome
Trisomy 18- Edwards syndrome
Trisomy 13 - Patau Syndrome

Question 29

What does DNA stand for and what are its three parts?

Answer 29

Deoxybonucleic acid
-Deoxyribose
- phosphate groups
- nitrogenous bases

Question 30

What are the four nitrogenous bases of DNA?

Answer 30

Adenine
Cytosine
Guanine
Thymine

Question 31

Dna replication

Answer 31

1. Helicase splits the helix.
2. Gyrase let’s helix spin to relieve tension
3. Primase tells DNA polymerase where to start copying.
4. Polymerase makes polymer of DNA on each strand, replicating it.
5. Ligase binds the loose ends together.
6. Polymerase goes back and checks for errors and mutations.

Question 32

Transcription

Answer 32

1. Transcription Factor proteins bind to promoter regions of DNA
2. Rna polymerase reads and copies mRNA based off DNA
3. Enzymes edit the mRNA. The MRNA then leaves the nucleus and finds a ribosome.

Question 33

Which organelle is the site of translation?

Answer 33

Ribosome

Question 34

Translation

Answer 34

1. The ribosome moves left to right reading the mRNA.
2. As the mRNAs codons are expressed, tRNAs will connect if their anti codons fit.
3. Amino acids connect in a polypeptide chain in the order given by mRNA.
4. Once the amino acids are attached, the tRNA drifts away.
5. The polypeptide chain will fold up according to its amino acids chemistry.
6. Empty trnas and free amino acids are properly combined together by a family of enzymes for future translation.

Question 35

Define evolution

Answer 35

Genes will change in a population over time

Question 36

How do genes change in populations? Name all 5 ways

Answer 36

• Non-Random mating
  -Mutations (only one of these that adds not deletes information)
• migration
  -Drift (random events can kill off parts of a population)
• selection (when genes do not evenly reproduce)