Genetics - Key Vocab

Question 1

Cell Membrane

Answer 1

Controls what enters and leaves the cell

Question 2

Nucleus

Answer 2

Contains the DNA (chromosomes)

Question 3

Chromosome

Answer 3

A strand/piece of DNA

Question 4

Cytoplasm

Answer 4

Where chemical reactions take place

Question 5

Mitochondria

Answer 5

Respiration occurs here

Question 6

Variation

Answer 6

The difference between individuals of the same species

Question 7

What does DNA stand for?

Answer 7

Deoxyribonulceic Acid

Question 8

Deoxyribonulceic Acid (DNA)

Answer 8

The chemical molecule in the nucleus that carries our genetic code.

Question 9

DNA is arranged into long, coiled molecules called ___________.

Answer 9

Chromosomes.

Question 10

Normal human body cells (e.g skin cell) have __ chromosomes, or __ pairs.

Answer 10

• 46
• 23

Question 11

_____ ___ _____ (sperm and egg) have half the amount of chromosomes that normal human body cells have.

Answer 11

Human sex cells

Question 12

Human sex cells have __ chromosomes.

Answer 12

23

Question 13

Genetic material is stored in the ______ of all cells. This material is called ___. It contains information needed to make an organism.

Answer 13

• nucleus
• DNA

Question 14

DNA is arranged into strands called ___________.

Answer 14

Chromosomes

Question 15

You have __ chromosomes in each cell, arranged into 23 _____.

Answer 15

• 46
• pairs

Question 16

Half the chromosomes come from the ___, and half from the dad.

Answer 16

mum

Question 17

What are genes?

Answer 17

Along the length of each chromosome there are coding regions called genes.

Question 18

A gene is a _______ __ _ __________ that codes for a particular characteristic.

Answer 18

• section of a chromosome

Question 19

A gene is a section of a chromosome that codes for a __________ ______________.

Answer 19

• particular characteristic

Question 20

For each gene, we inherit ___ _____ of the gene (one from our mother, one from our father).

Answer 20

• two forms

Question 21

Each form of the gene is called an ______.

Answer 21

• allele

Question 22

What is an allele?

Answer 22

An allele is a different form a gene.

Question 23

Alleles are ________ or _________.

Answer 23

• dominant
• recessive

Question 24

Dominant alleles are always expressed even if only one of the alleles is dominant.

Answer 24

e.g. BB or Bb

Question 25

Recessive alleles are only expressed if there are 2 recessive alleles.

Answer 25

e.g. bb

Question 26

A person has two alleles for hair colour - one brown and one blonde. What colour hair will they have?

Answer 26

Brown hair colour as it is the dominant one.

Question 27

If an individual has 2 identical alleles (e.g. BB, tt) for a characteristic (e.g. two blue eyes alleles) these are called __________ _______.

Answer 27

• homozygous alleles

Question 28

If an individual has 2 different alleles (e.g. Bb, Tt) for a characteristic (e.g. a blue allele and a brown allele) these are called ____________ _______.

Answer 28

• heteozygous alleles

Question 29

Genotype

Answer 29

this describes the alleles of an individual e.g., BB, Tt, ss

Question 30

Phenotype

Answer 30

This describes the physical appearance of an individual e.g. Brown eyes, Tall, curly hair

Question 31

Gamete

Answer 31

Sex cell

Question 32

An allele that controls a characteristic when it is present on only one of the chromosomes.

Answer 32

Dominant Allele

Question 33

An allele that controls a characteristic only if the dominant allele is not present.

Answer 33

Recessive Allele