Genes, Inheritance, & Selection

Question 1

describe the natural selection process

Answer 1

1variation caused by mutations
2competition for food in the environment and some organisms have an advantage
3higher chance for survival
4more chance to reproduce
5next generation have better adapted variations

Question 2

who was the theory of natural selection put forward by

Answer 2

charles darwin - ‘survival of the fittest’

Question 3

what are alleles?

Answer 3

different versions of the same gene

Question 4

homozygous dominant meaning?

Answer 4

two copies of the dominant allele

Question 5

homozygous recessive meaning?

Answer 5

two copies of the recessive allele

Question 6

what does heterozygous mean?

Answer 6

when there is a variation in two alleles of a a gene

Question 7

what is continuous variation?

Answer 7

many small differences for a particular characteristic because of both genetic and environmental causes

Question 8

what is discontinuous variation?

Answer 8

when there are distinct differences for a characteristic caused by genetic variation

Question 9

what does the human genome contain?

Answer 9

all of the genetic information: coding DNA and non - coding DNA

Question 10

what is coding DNA?

Answer 10

genes of an organism which give information on how to synthesize proteins

Question 11

what is non - coding DNA?

Answer 11

doesn’t code for proteins but can cause activation or deactivation of genes in the coding DNA

Question 12

what is sexual reproduction?

Answer 12

involves the fusion of the nuclei of two gametes to form a zygote (fertilised egg cell) and the production of an offspring

Question 13

what are the gamates of flowering plants called?

Answer 13

pollen cells and egg cells

Question 14

what are some advantages of sexual reproduction?

Answer 14

1 increased genetic variation
2 survival advantage because species can adapt to the new environment
3 disease is less likely to affect population because of variation

Question 15

what are some disadvantages of sexual reproduction?

Answer 15

1 takes time and energy to find mates
2 difficult for some species to reproduce

Question 16

key facts about meiosis

Answer 16

1 four genetically different haploid daughter cells
2 two divisions
3 produces gametes

Question 17

what is asexual reproduction?

Answer 17

only one parent is required so the offspring are clones

Question 18

what are some advantages of asexual reproduction?

Answer 18

1 population increases rapidly in correct conditions
2 can exploit suitable environments quickly
3 more time and energy efficient
4 much faster than sexual reproduction

Question 19

what are some disadvantages of asexual reproduction?

Answer 19

1 no genetic variation
2 may only be suitable for one habitat
3 disease can affect whole population as there is no genetic variation

Question 20

what is evolution?

Answer 20

the change in adaptive features of a population over time because of natural selection

Question 21

explain the process of antibiotic resistance in bacteria

Answer 21

variation caused by mutations so some bacteria become resistant to the antibiotic so the resistant bacteria do not die when the population is treated with the antibiotic so they reproduce with no competition and pass on the genes for antibiotic resistance to the next generation

Question 22

who developed the theory of evolution

Answer 22

wallace

Question 23

what is Linnaeus’s system of classification?

Answer 23

kingdom, phylum, class, order, family, genus, species

Question 24

what are the two types of classification?

Answer 24

artificial (physical characteristics) and natural (similarities in DNA)

Question 25

what is molecular phylogeny

Answer 25

how the base sequences in a mammal’s DNA are more closely related to all other mammals

Question 26

what are DNA base sequences used to code for

Answer 26

amino acid sequences in proteins

Question 27

what is classification

Answer 27

the process of placing organisms into different groups based on their similarities

Question 28

what are the 5 kingdoms

Answer 28

-animals -fungi -plants -protists -prokaryotes

Question 29

what does fungi reproduce

Answer 29

spores

Question 30

what is Darwin's theory

Answer 30

natural selection - 'survival of the fittest'

Question 31

what is a clone

Answer 31

an organism which is genetically identical to its parent

Question 32

what is mutation

Answer 32

change in the sequence of DNA bases

Question 33

what is an evidence for evolution

Answer 33

fossils suggesting that humans evolved from apes

Question 34

what are the two types of alleles

Answer 34

dominant and recessive

Question 35

what are haploid cells

Answer 35

cells which contain one set of chromosomes (23)

Question 36

what are diploid cells

Answer 36

cells which contain two sets of chromosomes (23 pairs)

Question 37

what is a genotype

Answer 37

combination of alleles present in an organism

Question 38

what is a phenotype

Answer 38

physical characteristics observed in an organism

Question 39

what is a genome

Answer 39

all the genetic material present in an organism

Question 40

what is a chromosome

Answer 40

a structure made from coiled DNA

Question 41

are gametes haploid or diploid and why

Answer 41

hapoid so both the egg and sperm get half the amount of chromosomes

Question 42

what do fossils tell us?

Answer 42

when an organism lived, where an organism lived, and how a species changed over time or how similar it is to current day species

Question 43

advantage of classification

Answer 43

each species have a unique name which avoids confusion

Question 44

what is single gene inheritance

Answer 44

each individual inherits two alleles for a particular gene, one from each parent

Question 45

give three reasons why the fossil record can be unclear for older species.

Answer 45

- fossils are buried deeper so harder to find - organisms bodies were soft so most of the tissue decayed - fossils are smaller so harder to find

Question 46

what is a problem with antibiotic resistance

Answer 46

- theyre not effective - new antibiotic drugs have to be made which takes time