Biology 6.1.6

Question 1

What are ‘Gametes’?

Answer 1

Gametes are Sex Cells.

Question 2

What are ‘Chromosomes’?

Answer 2

Chromosomes are Thread-Like Structures of DNA, Carrying Genetic Information in the Form of Genes. They are Located in the Nucleus of Cells.

Question 3

What are ‘Genes’?

Answer 3

Genes are Short Lengths of DNA, Found on Chromosomes. They Code for Specific Proteins.

Question 4

What are ‘Alleles’?

Answer 4

Alleles are Different Versions of a Particular Gene. EG Blue Eyes & Green Eyes are Alleles of the Eye Colour Gene.

Question 5

What is a ‘Dominant Allele’?

Answer 5

A Dominant Allele is Always Expressed, even if only 1 Copy is Present.

Question 6

What is a ‘Recessive Allele’?

Answer 6

A Recessive Allele is Only Expressed if 2 Copies are Present.

Question 7

What is a ‘Homozygous’?

Answer 7

If the 2 Alleles of a Gene are the Same, we Describe the Individual as being Homozygous. (Homo = Same).

Question 8

What is a ‘Genotype’?

Answer 8

The Combination of Alleles that Control Each Characteristic is Called the Genotype.

Question 9

What is a ‘Phenotype’?

Answer 9

The Observable Characteristics of an Organism. EG Hair Colour.

Question 10

Some Characteristics are Controlled by a Single Gene. The Inheritance of these Single Genes is Called…

Answer 10

Monohybrid Inheritance.

Question 11

What is ‘Monohybrid Inheritance’?

Answer 11

The Inheritance of Single Genes that Control a Certain Characteristic.

Question 12

As we have 2 Copies of Each Chromosome, we have 2 Copies of Each Gene, & therefore 2 ___ for Each Gene.

Answer 12

Alleles.

Question 13

1 of the Alleles is Inherited from the ___, & the other from the ___.

Answer 13

Mother, Father.

Question 14

Alleles do not have to ‘say’ the same thing. EG: an Individual has 2 Copies of the Gene for Eye Colour, but 1 ___ could be for Brown Eyes, & 1 ___ could be for Blue Eyes.

Answer 14

Allele, Allele.

Question 15

The Combination of Alleles that Control Each Characteristic is Called the…

Answer 15

Genotype.

Question 16

Alleles can be ___ or ___.

Answer 16

Dominant, Recessive.

Question 17

What Must happen in Order for a Dominant Allele Characteristic to Show Up in the Phenotype?

Answer 17

A Dominant Allele Only Needs to be Inherited from 1 Parent in Order for the Characteristic to Show Up in the Phenotype.

Question 18

What Must happen in Order for a Recessive Allele Characteristic to Show Up in the Phenotype?

Answer 18

A Recessive Allele Needs to be Inherited from Both Parents in Order for the Characteristic to Show Up in the Phenotype. In Other Words, in Order for a Recessive Allele to Appear in the Phenotype, there Must be no Dominant Alleles Present.

Question 19

What will Happen if there is Only 1 Recessive Allele?

Answer 19

If there is Only 1 Recessive Allele, it will Remain Hidden, & the Dominant Characteristic will Show in the Phenotype.

Question 20

If the 2 Alleles of a Gene are the Same, we Describe the Individual as Being…

Answer 20

Homozygous.

Question 21

An Individual could be Homozygous ___, or Homozygous ___. What do both mean? (2)

Answer 21

-Homozygous Dominant: Having 2 Copies of the Dominant Allele.

-Homozygous Recessive: Having 2 Copies of the Recessive Allele.

Question 22

If the 2 Alleles of a Gene are Different, we Describe the Individual as Being…

Answer 22

Heterozygous .

Question 23

Characteristics that are Controlled by More than One Gene are Described as Being…

Answer 23

Polygenic.

Question 24

The Inheritance of Polygenic Characteristics is Called…

Answer 24

Polygenic Inheritance.

Question 25

What Diagram can be Used to Predict Possible Combinations of Alleles?

Answer 25

Punnett Square.

Question 26

What does a ‘Punnett Square Diagram’ Show?

Answer 26

A Punnett Square Diagram Shows the Possible Combinations of Alleles that Could be Produced in the Offspring.

Question 27

What will be the Genotype for ‘rR’?

Answer 27

Heterozygous Dominant.

Question 28

What will be the Genotype for ‘RR’?

Answer 28

Homozygous Dominant.

Question 29

What will be the Genotype for ‘rr’?

Answer 29

Homozygous Recessive.