Inheritance, Variation and Evolution

Question 1

5 differences between mitosis and meiosis

Answer 1

1. Produces 2 identical daughter cells
   Produces 4 daughter cells
2. Daughter cells are genetically identical
   Daughter cells are not identical
3. Cells divide once
   Cells divide twice
4. At the end cells have 46 chromosomes
   At the end cells have 23 chromosomes
5. Used for growth, repair and asexual reproduction
   Used for production of gametes for sexual reproduction

Question 2

Cystic fibrosis

Answer 2

A disorder in cell membranes caused by a reccive allele

Question 3

What is polydactylyl

Answer 3

Extra fingers or toes caused by dominant allele

Question 4

What is someones genotype

Answer 4

What alleles they have

Question 5

Heterozygous

Answer 5

A genotype that has 2 different alleles

Question 6

Homozygous

Answer 6

A genotype that has 2 of the same alleles

Question 7

Phenotype

Answer 7

The physical expression of someone’s alleles

Question 8

How does variation happen

Answer 8

Inherited genes
Conditions of their development

Question 9

How does natural selection work

Answer 9

Randomly, an animal will mutate to have different genes to their parents.
This could be advantageous meaning they will live longer to reproduce and pass on their mutation to offspring

Question 10

How to restrict bacteria becoming resistant to antibiotics

Answer 10

Make sure a patient fully completes their anti-biotic cycle
Anti-biotics should be used when needed
Agricultural use of antibodies is resricted

Question 11

How do bacteria become resistant to antibiotics

Answer 11

Randomly a bacterium mutates to become resistant to antibiotics
Antibiotics are used by humans killing all non-resistant bacteria leaving only resistant bacteria
These bacteria that survive reproduce to form the new generation

Question 12

3 types of things that fossils could be

Answer 12

Actual remains of an organism
Mineralised bone of the animal
Footprints or traces of the organism

Question 13

Describe how you would selectively breed to get very spotty dogs

Answer 13

1. Find 2 spotty dogs and breed them to get the F2 generation
2. Breed the F2 generation together to get the F3 generation
3. This is because children inherit their genotype and therefore some of their phenotype from both of their parents

Question 14

How to genetically engineer a bacterium

Answer 14

1. Take DNA from human nucleus
   Take plasmid from bacterium
2. Cut desired gene from DNA using enzymes
3. Cut out a piece of the plasmid using enzymes
4. Gene is inserted into plasmid
5. The plasmid is inserted back into the bacterium which multiplies many times

Question 15

Who made the classification system

Answer 15

Ireane (just kidding)
Linneaus

Question 16

Name the classification system going down

Answer 16

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 17

Who made the 3 domain addition to the classification system

Answer 17

Woase

Question 18

Advantages of sexual reproduction

Answer 18

Variation in offspring
Variation can adapt to environment better
Can be used by humans in selective breeding

Question 19

Advantages of asexual reproduction

Answer 19

Only one parent needed
More energy efficient
Faster than sexual reproduction
Identical copies can be reproduced

Question 20

2 ways of how to clone a plant

Answer 20

A branch from a parent plant is cut off, lower leaves are removed and is placed in damp compost
Tissue taken from plant and placed in agar jelly, once big enough plant is moved to compost

Question 21

How do fungi reproduce

Answer 21

Sexually and asexually

Question 22

2 ways of how to clone an animal

Answer 22

Inseminate a cow artificially with bull sperm
Zygotes develop into embryos
Embryos split into smaller cells which are planted into host mothers to be born

The nucleus is taken from a female’s skin cell, and a nuclues is taken from a different female’s egg cell. The nucleus from the skin cell is put inside the egg cell without the nucleus, forms a zygote which is electrically shocked to start cell division, the now embryo is placed into a surrogette mother where it develops

Question 23

Why was Darwin’s theory not initially accepted

Answer 23

Religious ideas
Insufficient evidence at the time
No knowledge of genetics at the time

Question 24

Label a nucleotide

Answer 24

Phosphate
Sugar Base

Question 25

Which bases bond to which bases

Answer 25

A-T
C-G

Question 26

Steps in protein synthesis

Answer 26

The rRNA is copied to the smaller tRNA
Which can fit out the nucleus to go to the Ribosome
Binds to ribosome
mRNA binds to every 3 bases, (2 amino acids join)
Amino acid strands form a 3D shape

Question 28

Steps in speciation

Answer 28

1. Parts of a population become geographically isolated from each other
2. Random mutations occur in the 2 populations and if the mutations in both populations are better adapted to their different environments that animal will survive longer to reproduce and pass on their mutation (genes) to their offspring
3. The 2 populations eventually evolve so differently that when brought back together their offspring will be infertile

Question 29

Embryo screening

Answer 29

Genetic tests carried out to see if an embryo has a faulty allele