Genetics Definitions For NCEA Exam

Question 1

Gene

Answer 1

Made of DNA, an instruction for a set protein.

Question 2

DNA

Answer 2

Genetic material, instruction to build an organism.

Question 3

Allele

Answer 3

Different form of a gene.

Question 4

Chromosome

Answer 4

Made from DNA, contains genes, has 46, 23 pairs.

Question 5

Nucleotide

Answer 5

Base block of DNA, sugar, phosphate, base

Question 6

Semi Conservative

Answer 6

Half new, half old.

Question 7

Complimentary Base Pair Rule

Answer 7

A goes to T, C goes to G.

Question 8

Sexual Reproduction

Answer 8

2 parents, genetic variation.

Question 9

Asexual Reproduction

Answer 9

1 parent, no genetic variation.

Question 10

DNA Replication

Answer 10

Doubling up or making copies of DNA.

Question 11

Genotype

Answer 11

The 2 alleles.

Question 12

Phenotype

Answer 12

The physical feature/characteristic.

Question 13

Test Cross

Answer 13

Crossing an individual with an individual who is HOMOZYGOUS RECESSIVE.

Question 14

Mutation

Answer 14

A sudden permanent change in the DNA sequence.

Question 15

Mutagen

Answer 15

Causes a mutation, (e.g x-rays, UV rays, chemicals e.t.c)

Question 16

Meiosis

Answer 16

Cell division which creates gametes, occurs in sex organs, produces 4 genetically different daughter cells, half number of chromosomes.

Question 17

Mitosis

Answer 17

Cell division which creates 2 genetically identical daughter cells, occurs in body. Purpose is growth & repair. Full number of chromosomes.

Question 18

Variation

Answer 18

Survival of a species through meiosis. A difference in base sequence.

Question 19

Environment

Answer 19

The habitat in which you live, e.g temperature, food, water, wind, disease.

Question 20

Gamete

Answer 20

Sex cell (sperm or egg), contains half number of chromosomes.

Question 21

Zygote

Answer 21

Cell formed when a sperm cell fuses with an egg cell. (Fertilised egg).

Question 22

Somatic

Answer 22

Body cell, contains full amount of chromosomes.

Question 23

Homozygous

Answer 23

2 same alleles.

Question 24

Heterozygous

Answer 24

2 different alleles.

Question 25

Recessive

Answer 25

Only show if dominant not present, e.g bb.

Question 26

Dominant

Answer 26

It will be EXPRESSED if present.

Question 27

Crossing Over

Answer 27

Occurs during meiosis a homologous pair swaps a section of DNA for the same gene.

Question 28

Homologous Pair

Answer 28

Pair of chromosomes with the same genes one from each parent.

Question 29

Independent Assortment

Answer 29

The random alignment of the homologous pair along the equator of the cell during meiosis.

Question 30

2n

Answer 30

Diploid (means twice something else).

Question 31

n

Answer 31

Haploid (means one of something).

Question 32

Pure breeding

Answer 32

A group of identical individuals that always produce offspring of the same phenotype when interbred.

Question 33

Fertilisation

Answer 33

Fusing of 2 gametes, female & male to form a zygote.

Question 34

Inherited

Answer 34

What comes from the individuals parents.

Question 35

Non-Inherited

Answer 35

What doesn’t come from the individuals parents.