Chapter 3 - Heredity

Question 1

DNA Full Name

Answer 1

Deoxyribonucleic Acid.

Question 2

DNA Does

Answer 2

Makes proteins that are responsible for producing physical traits. i.e eye colour.

Question 3

Gene

Answer 3

Segment of DNA that codes a specific protein.

Question 4

Gene Process

Answer 4

Step 1. The gene transcribes into a molecule called RNA.

Step 2. The RNA carries the genes sequence to a cell structure called a ribosome - where a protein is built.

Question 5

RNA

Answer 5

Ribonucleic Acid

Question 6

Dogma

Answer 6

DNA to RNA to Protein is so specfic and key in living things that its reffered to as the Central Dogma of Biology/Molecular Biology.

Question 7

Chromosomes

Answer 7

Reproductive cells contain DNA in the form of structures called Chromosomes.

Question 8

Chromosomes in Normal Body Cells

Answer 8

46 Chromosomes each.

Question 9

Chromosomes in Reproductive Cells

Answer 9

23 Chromosomes each.

Question 10

Chromosomes Stored

Answer 10

Chromosomes that store DNA are located in the cells nucleus.

Question 11

Chromosomes Breakdown

Answer 11

A chromosome consists of two identical chromatids attached at the centromere. Hundreds/thousands of genes can be stored on once chromosome.

Question 12

Alleles

Answer 12

Different versions of a gene. Most genes have 2 alleles, more are possible. i.e eye colour (Blue/Brown), blood type (A,B & O).

Question 13

Mutations

Answer 13

New Alleles for a gene. Mutation is a random change in the base sequence of a gene.

Question 14

Mutation Types

Answer 14

Single Base Change, Additions & Deletions.

Question 15

Crossing Over

Answer 15

Before chromosomes are separated, they go through s process called crossing over. An arm from each chromosome literally “crosses over” the other, allowing the arms to trade segments.

Question 16

Enviromental Altering of Traits

Answer 16

Some traits are a result of a combination of alleles and environmental factors.

Question 17

Enviromental Factors

Answer 17

Height - Poor diet can limit how tall one can grow/stunt ones growth.
Handedness - Injury to dominant hand can require one to learn to use the other.
Cancer - Lifestyle choices can increase ones risk. E.g smoking/drinking/diet etc.

Question 18

Expression of Traits

Answer 18

When a gene is actively used to make a protein it is said to be turned on or expressed.
Some genes are expressed all the time.
Others only when a specific protein is needed.

Question 19

Epigenetics

Answer 19

The study of how genes are turned on and off.

Question 20

Enviromental Epigenetics

Answer 20

Environmental factors can determine which genes are expressed. E.g Temperature.

Question 21

Inheritance

Answer 21

You have two copies of every gene. One from each parent.

Question 22

Genotype

Answer 22

Your combination of alleles for a specific gene.

Question 23

Phenotype

Answer 23

Physical appearance for a trait. Determined by your genotype.

Question 24

Simple Inheritance

Answer 24

Gene has one dominant allele and one recessive allele.

Question 25

Dominant Allele

Answer 25

Having at least one dominant allele means he/she will have the dominant phenotype.

Question 26

Recessive Allele

Answer 26

Two recessive alleles required for he/she to have recessive phenotype.

Question 27

Punnett Square

Answer 27

A chart used to calculate the probability of parents passing on a trait.

Question 28

Rules For Punnett Square

Answer 28

1. One parents alleles go across the top, and one down the left side. 2. Match the alleles inside the square to show possible genotypes. 3. Each square has a 25% chance of being inherited.

Question 29

Pedigree Chart

Answer 29

Used to trace the inheritance of a trait through generations of a family.