Inheritance, Variation And Evoluation

Question 1

What structure does DNA have?

Answer 1

A double helix structure

Question 2

What is a gene and what does it do?

Answer 2

A small section of DNA found in a chromosome, each gene codes for a particular sequence of amino acids

Question 3

What is a genome ?

Answer 3

A entire set of genetic material in an organism

Question 4

What is DNA made up of ?

Answer 4

DNA strands are polymers made up of lots of repeating units called nucleotides, they consist of a sugar

Question 5

What is the pairs of the DNA ?

Answer 5

A-T and C-G called complementary base pairing

Question 6

What are proteins functions ?

Answer 6

-enzymes -biological catalysts
-hormones -carry messages
-structural proteins -physically strong

Question 7

What are mutations ?

Answer 7

Changes to the genetic code

Question 8

What are the 3 different type of mutations ?

Answer 8

-Insertions
-deletions
-substitutions

Question 9

What are insertion mutations in the DNA

Answer 9

A new base is inserted into the DNA base sequence of where it should be

Question 10

What are deletions and substitutions mutations ?

Answer 10

Deletions are when a random base is deleted from DNA base sequence
Substitution mutations are a random base sequence is changed

Question 11

Sexual reproduction is ?

Answer 11

Genetic information from 2 organisms (mother and father) ut combined to produce off spring

Question 12

What is asuexual reproduction?

Answer 12

Only 1 parent so the offspring is formed through mitosis

Question 13

What are diffrences between asexual and sexual reproduction?

Answer 13

Sexual
-2 parents
-genetically diffrent
- funsion of gamete
Asexual
-1 parent
-genetically identical
-no funsion of gamete

Question 14

How are gametes produced ?

Answer 14

Meiosis

Question 15

Process of meiosis in reproduction?

Answer 15

-The cell duplicates its genetic information
-then pulled apart so each cell has some of the mothers and father chromosomes
-the chromosomes line up in the center then there arms are pulled apart
-you get 4 gametes each have a single set of chromosomes, genetically diffrent

Question 16

What happens when two gameyes fused during fertilisation ?

Answer 16

The resulting cell divides by mitosis to make a copy of its self, this repeats to produce lots of new cells in an embryo

Question 17

Pros and cons of sexual and asexual reproduction?

Answer 17

Sexual
-variation in offspring
-adapted characteristics
-selective breeding
Asexual
-less energy
-faster
-1 parent
-have favourable conditions

Question 18

What many pares of chromosomes are in every human body cell

Answer 18

23

Question 19

What are the differences is male and female chromosomes ?

Answer 19

Males have X-Y chromosome Y chromosomes is male characteristics
Females have X-X chromosomes
XX combination allows female characteristics

Question 20

How to find out the probability of boy or girl is ?

Answer 20

Genetic diagram- models that show all the genetic outcomes

Question 21

If an organism has 2 alleles for a particular gene that are the same then it’s ?

Answer 21

Homozygous

Question 22

If 2 alleles for a particular gene are different then it’s ?

Answer 22

Heterozygous

Question 23

The allele for the characteristic that’s shown is what ?

Answer 23

The dominant allele (used in a capital letter)

Question 24

The characteristic that isn’t showed is called what

Answer 24

Recessive allele (small letter)

Question 25

Some disorders can be inherited this can be checking how ?

Answer 25

these can be screened for in embryos

Question 26

What is cystic fibrosis?

Answer 26

It’s a genetic disorder of the cell membranes, results in thick sticky mucus In the air passages (recessive allele)

Question 27

What is polydactyly ?

Answer 27

It’s a genetic disorder when a baby is born with a extra finger or toe (dominant allele)

Question 28

Pros and cons of embryonic screening ?

Answer 28

Pros -help to stop people suffering -cost the government -laws to stop it Cons -implies that people with genetic problems are “undesirable” -it’s expensive -make people chose there beef embryo

Question 29

What did Mendel realise ?

Answer 29

-characteristics in plants are determined by heredity in plants -hereditary units are passed on to offspring unchanged from both parents -hereditary units can be dominant or recessive

Question 30

What are the 2 types of variation ?

Answer 30

Genetic and environmental variation

Question 31

What is genetic variation?

Answer 31

A offspring or child that has the combing genes of both parents causing a variation

Question 32

What is environmental variation ?

Answer 32

The conditions an organism is in causes diffrences

Question 33

What is Charles Darwin’s theory about evolution ?

Answer 33

Evaluation by natural selection, the organisms with the most suitable characteristics for the environment would be more successive therefore surviving

Question 34

What is speciation ?

Answer 34

Over a long period of time, the phenotype of organisms change so much due to natural selection a new species is formed

Question 35

How can species become extinct ?

Answer 35

-environment changed quickly -new predictor -new diseases -can’t compete for foot -catastrophic event

Question 36

What is selective breeding ?

Answer 36

When humans artificially select the best animals to breed on characterises

Question 37

What is examples of selective breeding ?

Answer 37

-animals that produce more meat or milk -cells with disease resistance -decorative plants

Question 38

What is the problem with selective breeding ?

Answer 38

Reduced the gene pool- number of diffrent alleles

Question 39

What is genetic engineering?

Answer 39

To transfer a gene responsible for a desirable characteristic from one organisms genome into another organism so that it also has the desired characteristics

Question 40

How does genetic engineering happen ?

Answer 40

-a useful gene is isolated from one organisms genome using enzymes -a vector is usually a fruit or bacterial plasmid -when the vector is introduced to the target organism, useful gene is inserted into its cell(s)

Question 41

What are pros and cons of GM crops ?

Answer 41

Pros - increase in yield -they could increase nutrients in LIC company’s Cons -affect the number of wild flowers -might not be safe

Question 42

What are the 2 ways plants can be cloned ?

Answer 42

-tissue culture -cutting

Question 43

What is tissue culture ?

Answer 43

A few plant cells, put in growth medium with hormones then they grow into new plants-clones

Question 44

What is cutting ?

Answer 44

-gardeners can take cutting from hod patent plant then produce genetically identical copies -produce quickly and cheaply

Question 45

How can animal clones be made ?

Answer 45

Embryo transplants

Question 46

How are animal clones made using embryo transplants ?

Answer 46

Produce cloned offspring through the sperm cells and egg cells are taken then used to artificially fertilise

Question 47

What are fossils ?

Answer 47

The remains of plants and animals from thousands of years ago

Question 48

What are the 3 ways fossils form in rocks ?

Answer 48

-gradual replacement by minerals -casts and impressions -preservation in places where no decay happens

Question 49

What is gradual displacement ? Examples?

Answer 49

Things like teeth,shells,bones ect.. which don’t decay easily and can last a long time when buried

Question 50

What is casts and impressions ?

Answer 50

How fossils are formed when an organism is buried in a soft material

Question 51

What is isolation ?

Answer 51

Where populations of a species are seperrated, this can happen due to physical barriers

Question 52

How can bacteria become antibiotic-resistant ?

Answer 52

All organisms or bacteria sometimes develop random mutations in there DNA making them resistant

Question 53

What is classification ?

Answer 53

Organising living organisms into groups

Question 54

In the three-domain system, organisms are split into 3 large groups called ?

Answer 54

-Archaea -Bacteria -Eukaryota

Question 55

What is the independent variable ?

Answer 55

What you change ?

Question 56

What is the control variable ?

Answer 56

What you keep the same

Question 57

What is the dependent variable ?

Answer 57

What you measure