Topic 14 - inheritance

Question 1

DNA?

Answer 1

DNA molecules are large and complex. They carry the genetic code that determines the characteristics of a living organism.

Question 2

What is the backbone of DNA double helix?

Answer 2

The backbone of the DNA double helix consists of alternating phosphate and deoxyribose sugar molecules.

Interlinking bases hold the two sides together.

Question 3

Chromosomes?

Answer 3

Chromosomes are thin strands of DNA (deoxyribonucleic acid).

They are subdivided intogenes.

Question 4

Humans have how many chromosomes?

Answer 4

Humans have46 chromosomesarranged in23 pairs.

Question 5

Genes?

Answer 5

A gene is a short length of DNA found on a chromosome that codes for a particular characteristic or protein.

Question 6

DIPLOID.

Answer 6

All body cells (somatic cells) have pairs ofeach chromosomes

Question 7

HAPLOID.

Answer 7

Sex cells have a single copy of each chromosome

Question 8

GAMETE.

Answer 8

The scientific word for a sex cell is

Question 9

Human diploid number is

Answer 9

46.

Question 10

Human haploid number is

Answer 10

23.

Question 11

ALLELES

Answer 11

Differing forms of a gene are

Question 12

PHENOTYPE

Answer 12

is the physical appearance resulting from the inherited information.

Question 13

GENOTYPE

Answer 13

the combination of alleles that control an organism’s characteristics

Question 14

Alleles can be (3)

Answer 14

1.DOMINANT (always expressed in the phenotype). (capital)

2.RECESSIVE (only expressed when there are two recessive alleles). (lower case)

3.CODOMINANT (both alleles are expressed). (mixed)

Question 15

BB eye colour? (B is brown b is blue)

Answer 15

BB has the phenotype brown. It is HOMOZYGOUS dominant

Question 16

bb eye colour? (B is brown b is blue)

Answer 16

bb has the phenotype blue. It is HOMOZYGOUS recessive.

Question 17

Bb eye colour? (B is brown b is blue)

Answer 17

Bb has the phenotype brown. It is the HETEROZYGOUS genotype.