B6 - Inheritance, Variation & Evolution

Question 1

What does DNA stand for?

Answer 1

DeoxyriboNucleic Acid

Question 2

What type of molecule is DNA

Answer 2

Polymer

Question 3

Where is DNA found in a cell?

Answer 3

Nucleus

Question 4

What is a gene?

Answer 4

A gene is a short section of DNA

Question 5

What is the definition for genome?

Answer 5

The entire genetic material in an organism

Question 6

What are the repeating units called in DNA polymers?

Answer 6

Nucleotides

Question 7

What 3 things does each nucleotide contain?

Answer 7

• 1 sugar group
• 1 phosphate group
• 1 ‘base’

Question 8

What do the sugar and phosphate groups form?

Answer 8

Backbone to the DNA

Question 9

What are the names of the 4 bases?

Answer 9

A, T, G, C

Question 10

What are the base pairings?

Answer 10

A and T, G and C

Question 11

How many bases does each amino acid get coded by?

Answer 11

3

Question 12

Where are proteins made in a cell?

Answer 12

Ribosomes

Question 13

What does mRNA stand for?

Answer 13

messenger RiboNucleic Acid

Question 14

What does mRNA do?

Answer 14

Transfers genetic code from DNA to the ribosomes

Question 15

Name 3 examples of types of proteins

Answer 15

1) Enzymes
2) Hormones
3) Structural proteins

Question 16

What happens to a chain of amino acids once it’s been assembled?

Answer 16

It folds into a unique shape, allowing the protein to do its designated task

Question 17

What are the 3 different ways that mutations can change a DNA base sequence?

Answer 17

1) Insertions - where a new base is inserted into the DNA base sequence where it shouldn’t be
2) Deletions - when a random base is deleted from a base sequence
3) Substitutions - when a random base in the DNA base sequence is changed to a different base

Question 18

What is sexual reproduction?

Answer 18

Where genetic information from 2 organisms (mum and dad) is combined to produce offspring which are genetically different to either parent

Question 19

In sexual reproduction, the mum and dad produce gametes by what process?

Answer 19

Meiosis

Question 20

In humans, how many chromosomes are in each gamete?

Answer 20

23

Question 21

How many parents are there in asexual reproduction?

Answer 21

1

Question 22

What process does asexual reproduction happen by?

Answer 22

Mitosis

Question 23

What is a mutation?

Answer 23

A random change in an organism’s DNA

Question 24

What do mutations do?

Answer 24

They change the sequence of the DNA bases in a gene, which produces a genetic variant

Question 25

Explain the process of meiosis

Answer 25

1) The genetic information is duplicated. After this, the chromosomes begin to arrange themselves into pairs 2) In the first division of meiosis the chromosome pairs line up in the centre of the cell 3) The pairs are then pulled apart so each new cell only has one copy of each chromosome. Some of the father's and mother's go into each new cell 4) In the second division, the chromosomes line up again in the centre if the cell. The arms of the chromosome are pulled apart 5) You get 4 gametes, each with only a single set of chromosomes in it. Each of the gametes is genetically different from the others because the chromosomes all get shuffled up during meiosis and each gamete only gets half of them, at random

Question 26

What do the 2 gametes do after they've fertilised?

Answer 26

The resulting new cell divides by mitosis to copy itself

Question 27

What are some advantages of sexual reproduction over asexual reproduction?

Answer 27

- The organism inherits genes from both parents, which produces variation in the offspring - Variation increases the chance of a species surviving a change in the environment - Because adapted species have a better chance of survival, they're more likely to breed successfully and pass the genes for characteristics on - We can use selective breeding to speed up natural selection, allowing us to produce animals with desirable characteristics

Question 28

What are some advantages of asexual reproduction over sexual reproduction?

Answer 28

- Only one parent is needed - Uses less energy - Faster - Many identical offspring can be produced in favourable conditions

Question 29

How is a parasite transferred to a human by a mosquito?

Answer 29

When the parasite bites the human is when the parasite is transferred

Question 30

When does a parasite reproduce sexually and asexually?

Answer 30

- Sexually - when the parasite is in the mosquito | - Asexually - when the parasite is in the human

Question 31

How do fungi reproduce?

Answer 31

They release spores, which can become new fungi when they land in a suitable place

Question 32

What are 'runners' on strawberry plants?

Answer 32

- 'Runners' are stems which grow horizontally on the surface of the soil away from a plant - At various points along the runner, a new strawberry plant forms that is identical to the original plant

Question 33

How many of the 22 pairs of chromosomes are matched pairs that only control characteristics?

Answer 33

22

Question 34

Which pair of chromosomes are label XX or XY?

Answer 34

23rd pair

Question 35

Which chromosomes do males have?

Answer 35

XX

Question 36

Which chromosomes do females have?

Answer 36

XY

Question 37

How do you find the probability of getting a boy or a girl?

Answer 37

Draw a genetic diagram

Question 38

Why does genetic variation within the malarial parasite population increases whilst in the mosquito?

Answer 38

The malarial parasite secually reproduces whilst in the mosquito, which leads to genetic variation