Inheritance, Variation and evolution

Question 1

What are the 3 components of a nucleotide

Answer 1

Deoxyribs sugar
Phosphate molecule
Base

Question 2

Scientists that discovered DNA

Answer 2

Franklin- provided x-ray images
Watson
Crick

Question 3

2 Functions of DNA

Answer 3

Genetic code are segments of DNA that hold specific instructions.
Replication- cells divide to create new cells

Question 4

What is a genome?

Answer 4

Complete set of genetic material for an organism

Question 5

DNA

Answer 5

Long molecule made up two straws which are twisted together to make a spiral-double helix. Molecule of inheritance.

Question 6

How is protein synthesis carried out?

Answer 6

DNA unzips
Transcription (messenger is formed)
MRNA leaves the nucleus and enters the cytoplasm.
TRNA s attached to a specific amino acid
TRNA binds to MRNA

Question 7

Phenotype

Answer 7

Characteristics you can see

Question 8

Genotype

Answer 8

Genetic code ( can’t see)

Question 9

What are the types of mutation of DNA base sequences?

Answer 9

Insertation- A new base enters the sequence where it shouldn’t be. Amino acids will change.
Deletions- Random base is deleted from the sequence which has a knock on effect.
Substitution- A random base in the sequence is changed to a different base.

Question 10

Meiosis process

Answer 10

Parent cell
Chromosomes make identical copies of themselves.
Similar chromosomes pair up.
Sections of DNA get swapped
Pairs of chromosomes divide.
Chromosomes divide again.

Question 11

Feature of meiosis

Answer 11

Production of sex cells
Cell divides twice, forming four gametes or daughter cells.
Gametes are genetically different.

Question 12

What is Mendall’s experiment?

Answer 12

Take two plants; one which is pure-bred for tallness and one pure-bred for shortness and cross them.

Question 13

Heterozygous

Answer 13

Two different alleles (Bb)

Question 14

Homozygous

Answer 14

Two of the same alleles (BB) (bb)

Question 15

Allele

Answer 15

Different versions of the same gene.

Question 16

Cystic fibrosis and symptoms

Answer 16

Produce too much mucus- can use embryo screening.
Symptoms- Thick sticky mucus in airways.
Repeated chest infections
Poor digestion leading to malnutrition.
Blockage of bowels.
Fertility problems.

Question 17

Artificial insemination

Answer 17

Only one male can fertilise many females at the same time. This allows the farmer to pick the best genes.

Question 18

What is selective breeding?
What is the drawback?

Answer 18

Allowed the breeding of animals (working) which were obedient, fast and agile enough to do the jobs required.
It introduced many deformities through the distortion of characteristics.

Question 19

What is genetic engineering?

Answer 19

Process where the genome of an organism is modified by introducing another gene from a different organism to give a desired characteristic.

Question 20

Genetic engineering steps:

Answer 20

1. DNA that contains an insulin- coding gene is removed from cell.
2. Enzymes are used to isolate the desired gene.
3. Enzymes are used to insert the gene in to the DNA plasmid.
4. Bacteria reproduce through mitosis.
5. A large population with the new characteristic is created.
6. The gene is removed and transferred at an early stage of development to ensure all cells contain the gene.

Question 21

Clone

Answer 21

Genetically identical to the mother. Genetically identical copy of the original body cell.

Question 22

Cloning steps

Answer 22

1. Remove nucleus from an unfertilised egg cell.
2. The nucleus from an adult body cell is then inserted into the egg cell.
3. An electric shock causes the egg cell to divide to form embryo cells.
4. These embryo cells contain the same genetic information as the adult skin cell.
5. When the embryo has developed into a ball of cells, it is inserted into the womb of an adult female to continue its development.

Question 23

What are 3 advantages of cloning?

Answer 23

Genetically engineered animals can be cloned.
Save animals from extinction.
Produce stem cells for therapeutic purposes.

Question 24

What are 3 disadvantages of cloning?

Answer 24

Could lead to cloning babies.
Reduced variety in population.
Research the destruction of embryos.

Question 25

What is MRSA? Who is it a higher risk to?

Answer 25

Bacteria that is a 'super bug'. It is becoming increasingly resistant to antibiotics and is a risk to vulnerable.

Question 26

Symptoms of MRSA

Answer 26

High temperature (38) Chills Aches and pains Dizziness Confusion

Question 27

What are the 4 reasons resistance happens?

Answer 27

Competition Mutation -Variation Survival Genes

Question 28

How to prevent MRSA?

Answer 28

Don't overprescribe antibiotics. Always finish a course of antibiotics. Stop using antibiotics in farming.

Question 29

What are fossils?

Answer 29

Mineralised remains of living organisms, or of tracer left behind by organisms.

Question 30

Evolution

Answer 30

The process in which the characteristics of species change over many generations

Question 31

Where are fossils found?

Answer 31

Sedimentary rock

Question 32

Evidence provided by studying fossils

Answer 32

Size Shape Body structure Time period they lived in

Question 33

Who had the theory of evolution?

Answer 33

Darwin

Question 34

What is the definition of species?

Answer 34

A group of organisms that share a genetic heritage, are able to interbreed, and to create offspring that are also fertile.

Question 35

What is speciation?

Answer 35

Two species or two groups of animals that are so genetically different they cannot successfully interbreed.

Question 36

What are the 6 classes?

Answer 36

Mammals Birds Amphibians Fish Insects Worms

Question 37

What are the 7 levels?

Answer 37

Kingdom Phyllum Class Order Family Genus Species

Question 38

What did Woese do?

Answer 38

Developed the use of DNA sequences to refine classification. Introduced 3 domains

Question 39

What are the three domains?

Answer 39

Eukaryota -All animals, plants, fungi and protists Bacteria Archaea -Primitive bacteria surviving in extreme conditions.

Question 40

What is a long strand of DNA that contains many genes called?

Answer 40

Chromosome

Question 41

Where are proteins made

Answer 41

DNA (Ribosomes)