1.3 - Inheritance

Question 1

How many chromosomes do somatic cells have?

Answer 1

46

Question 2

What is mitosis?

Answer 2

The process by which somatic cells are formed

Question 3

How many chromosomes do the sex cells have?

Answer 3

23

Question 4

What is meiosis?

Answer 4

The process by which sex cells are formed

Question 5

What is homozygous dominant?

Answer 5

Having two dominant alleles e.g BB GG

Question 6

What is homozygous recessive?

Answer 6

Having 2 recessive alleles

Question 7

What is heterozygous?

Answer 7

Having a dominant and recessive allele

Question 8

What’s a phenotype?

Answer 8

The word description for a characteristc

Question 9

What’s a genotype?

Answer 9

The genetic description for a characteristic e.g BB, ee, Ee

Question 10

Why do men suffer from more sex related diseases than women?

Answer 10

Because the y chromosome is shorter so contains fewer genes

Question 11

How can genetic profiling be used?

Answer 11

• fingerprinting can be used to place people at a crime scene
• evidence for a paternity case

Question 12

How can DNA be used for closely related species?

Answer 12

• DNA Will be similar

- physical characteristics

Question 13

What does genetic engineering mean?

Answer 13

It involved the transfer of genes from one organism to another using bacteria

Question 14

What does transgenic mean?

Answer 14

Where an animal or plant contains foreign genes

Question 15

What are bacteria?

Answer 15

-microscopic single celled organisms that do not have a proper nucleus

Question 16

What do restriction enzymes do?

Answer 16

They cut DNA at specific points

Question 17

What do plasmids do?

Answer 17

They carry genes that are resistant to antibiotics

Question 18

3 examples of genetic engineering

Answer 18

• insulin production
• cystic fibrosis production
• haemophilia production

Question 19

What are the advantages of genetic engineering?

Answer 19

• production of new organisms
• treats inherited diseases
• processes are cheaper and more efficient

Question 20

What are the disadvantages of genetic engineering?

Answer 20

• inserted genes may be harmful as we have a lack of knowledge how they work
• new organisms could get out of control
• altered genes could be harmful to other organisms

Question 21

How does genetic engineering happen?

Answer 21

1. A plasmid is removed from a bacterium and a restriction enzyme cuts out a section
2. The same enzyme cuts out a piece of human DNA which is then inserted into the plasmid
3. The plasmid is inserted into the bacterium and it replicates by mitosis so each new cell has the new gene
   E.g insulin gene

Question 22

How does herbicide resistance in plants work?

Answer 22

1. Selecting a gene for herbicide resistance and cutting into a plasmid
2. Plasmid with a gene is inserted and so a plant becomes transgenic
3. Growing seeds in a petri dish containing herbicide so only transgenic plants grow
4. Transgenic plants grow in a field and farmer sprays throughout the year

Question 23

Who discovered DNA?

Answer 23

Watson and Crick