5.4 From Mendel to DNA

Question 1

What was Mendel the first person to suggest?

Answer 1

The idea of separately inherited factors

Question 2

Why did it take a long time for Mendel’s idea to be accepted?

Answer 2

Scientists didn’t know about genes and chromosomes until after Mendel had died

Question 3

What are Mendel’s factors now known as?

Answer 3

Genes

Question 4

What are genes?

Answer 4

Short sections of DNA, which is a very long molecule with a double helix structure

Question 5

What is a DNA fingerprint?

Answer 5

A unique DNA pattern used to identify people, except identical twins

Question 6

What do our chromosomes control?

Answer 6

Our characteristics

Question 7

What are chromosomes?

Answer 7

Large DNA molecules

Question 8

What is a gene made up of?

Answer 8

3 pairs of bases that code for a specific amino acid that join together to make proteins

Question 9

What letters are the bases made of?

Answer 9

C, A, T, G

Question 10

Name 3 effects of copying errors (mistakes in the bases)

Answer 10

• they could work better
• they could do nothing at all
• they could stop it from working

Question 11

What do mutations cause?

Answer 11

Different proteins

Question 12

What is a phenotype?

Answer 12

A physical aspect of the offspring, coded by a pair of chromosomes, one from the mother, one from the father

Question 13

What do all of your chromosomes make?

Answer 13

A genome

Question 14

In the inheritance punnet squares, how are the dominant alleles written?

Answer 14

As capital letters, the first letter of the word, eg. B for brown eyes

Question 15

In the inheritance punnet squares, how are the recessive alleles written?

Answer 15

As little letters, the first letter of the word, eg. b for blue eyes

Question 16

Define the dominant allele.

Answer 16

The characteristic that will appear in the phenotype of someone even if only one allele for it is inherited

Question 17

Define the recessive allele

Answer 17

The characteristic that will only appear in the phenotype if both of those alleles are inherited

Question 18

Define the phenotype of someone

Answer 18

Their physical appearance regarding a particular aspect

Question 19

Define genotype

Answer 19

The genetic make up regarding a particular aspect

Question 20

What does homozygous mean in regard to alleles?

Answer 20

Someone with 2 identical alleles for a characteristic

Question 21

What does heterozygous mean in regard to alleles?

Answer 21

Someone with 2 different alleles for a characteristic, the dominant one will decide the phenotype

Question 22

How can you predict a certain phenotype of an unborn child?

Answer 22

Compare the genotypes of the parents and calculate the percentage for each child’s genotype using a punnet square

Question 23

Who was Gregor Mendel?

Answer 23

A monk who discovered how characteristics were inherited