4.6.1.3 DNA and the genome

Question 1

What does DNA stand for?

Answer 1

Deoxyribonucleic acid

Question 2

What is the role of DNA

Answer 2

contains the instructions needed for an organism to develop, survive and reproduce

Question 3

What are chromosomes

Answer 3

These are coiled threads of DNA found in the nucleus of all cells

Question 4

What is a gene?

Answer 4

A length of DNA that codes for the making of particular protein (unit of inheritance)

Question 5

What is a genome?

Answer 5

Complete set of genes and its instructions

Question 6

What are bases?

Answer 6

4 types and their sequence determines the genetic instruction

Question 7

What are alleles?

Answer 7

Different varieties of a gene which code for a different version of the same characteristic (e.g eye colour)

Question 8

What is a diploid?

Answer 8

Containing two sets of chromosomes

Question 9

The difference between one molecule of DNA ( or gene) and another depends on the…

Answer 9

Order of the base pairs

Question 10

Why is there an unlimited number of possible arrangements of genes in an organism?

Answer 10

Because each organism is different and they vary in base arrangements

Question 11

Everyone has an unique DNA structure except..

Answer 11

Twins and clones

Question 12

What is a DNA molecule known as?

Answer 12

A double helix

Question 13

What are the 2 pairing base pairs in DNA?

Answer 13

Adenine - thymine
Guanine - cytosine

Question 14

State two properties of a double helix

Answer 14

DNA is coiled to form the arms of the chromosome
Cross sections made up of base pairs

Question 15

State information about the genome

Answer 15

This is all of the information that is in the chromosomes
There are over 20000 genes in humans
A special type of DNA is inherited via mother, comes from egg’s mitochondria.

Question 16

State properties of the phrase, inheritance.

Answer 16

Characteristics from both dad and mum
Siblings inherit some similar and some different characteristics from parents so may or may not look similar.

Question 17

What will there be for each characteristic e.g hair colour in the cells?

Answer 17

A certain combination of alleles

Question 18

What is a genotype?

Answer 18

This is the genes directly found inside of our cells.

Question 19

What is a phenotype?

Answer 19

The characteristics visible on our appearances

Question 20

Génotypes may have different alleles, but the ________ one will be expressed in the phenotype.

Answer 20

Dominant

Question 21

What is a dominant allele

Answer 21

This is a allele more likely to occur

Question 22

What is a recessive allele

Answer 22

This is an allele less likely to occur

Question 23

Define the term ‘heterozygous’

Answer 23

This is where there is one dominant allele and one recessive allele
Aa or Bb or cC

Question 24

Define the term ‘ homozygous ‘

Answer 24

Both dominant alleles or both recessive alleles
AA / aa BB / bb

Question 25

Are dominant alleles shown as capital letters or lowercase letters?

Answer 25

Capital

Question 26

Are recessive alleles shown as capital or lowercase letters?

Answer 26

Lowercase