B1 Genomes And Characteristics

Question 1

What are chromosomes?

Answer 1

Really long molecules of DNA

Question 2

What is the genome?

Answer 2

The entire genetic material of an organism.

Question 3

Where is genetic material stored in plant and animal cells and how is it arranged?

Answer 3

Stored in the nucleus, arranged into chromosomes.

Question 4

How many pairs of chromosomes do humans have?

Answer 4

23 pairs (46 chromosomes in total)

Question 5

What is a chromosome?

Answer 5

A very long molecule of DNA that’s coiled up.

Question 6

DNA is a polymer. What is a polymer?

Answer 6

A molecule that’s made up of smaller, repeating units called monomers.

Question 7

What are DNA monomers called?

Answer 7

Nucleotides

Question 8

How many strands of nucleotides does each DNA molecule contain and what is its structure?

Answer 8

Two strands of nucleotides, which coil together to form a double helix.

Question 9

What are genes?

Answer 9

The instructions in genomes.

A short length of DNA on a chromosome.

Question 10

What does each gene code for?

Answer 10

A particular sequence of amino acids, which are put together to make a specific protein.

Question 11

What is the process of making a big molecule (eg a protein) from lots of smaller proteins called?

Answer 11

Polymerisation.

Question 12

What do proteins control?

Answer 12

The development of different characteristics (eg dimples) and how an organism functions.

Question 13

What is an allele?

Answer 13

A different version of the same gene.

Question 14

What is the different version of the same gene called?

Answer 14

Alleles or genetic variants

Question 15

What is the combination of alleles an organism has for each gene called?

Answer 15

It’s genotype

Question 16

What makes a organisms genome unique?

Answer 16

It’s genotype.

Question 17

What is phenotype?

Answer 17

The characteristics the organism displays

Question 18

What do interactions with the environment affect?

Answer 18

They can modify the phenotype.

Question 19

Give an example of a how environment can affect the phenotype of a plant.

Answer 19

If a plant is grown in the sun it could grow green and luscious.

The same plant grown in the darkness would grow tall and spindly and its leaves would turn yellow.

Question 20

How are variations in phenotype determined?

Give a example of how height is determined.

Answer 20

By a mixture of genetic and environmental factors.

Example the max height a plant or animal can grow is determined by its genes, but whether it actually grows that tall depends on its environment.

Question 21

What is an organisms genome?

Answer 21

The entire genetic material of an organism (1 mark)

Question 22

What is an organisms

a) genotype
b) phenotype

Answer 22

a) an organisms genotype is the combination of alleles it has for each gene. (1 mark)
b) an organism’s phenotype is the characteristics it displays (1 mark)