inheritance, variation, evolution Flashcards
1
Q
asexual reproduction
A
- 1 parent
- no fusion of gamets
- production of genetically identical offspring
- mitosis
2
Q
gamets are
A
sex cells
3
Q
sexual reproduction
A
- fusion of male and female gametes
- mix of genetic information
- meiosis
4
Q
animal gametes
A
sperm + egg
5
Q
flowering plants gametes
A
pollen + egg
6
Q
meiosis
A
- copies of genetic information made
- Cell divides twice to form four gametes
- > single set of chromosomes (haploid)
- all gametes are genetically different
7
Q
genome of an organism
A
The entire genetic material of that organism
8
Q
uses of genome
A
- search for genes linked to disorders
- scientists understand cause of inherited disorders (how to treat)
- investigate how humans may have changed our time
9
Q
characteristic of genome are controlled by…
A
a single gene
10
Q
alleles
A
different forms
blue eyes, brown hair
11
Q
genotype
A
combination of alleles present in a gene
BB
12
Q
phenotype
A
how the alleles are expressed
blue eyes
13
Q
alleles can be either
A
- dominant
- recessive
14
Q
homozygous
A
two alleles are the same
BB,bb
15
Q
heterozygous
A
alleles are different
Bb
16
Q
dominant
A
captial letter
17
Q
recessive
A
lowercase letter
18
Q
monohybrid inheritance
A
1 gene involved
19
Q
polydactyl
A
extra finger or toe
->causes by dominant allele
20
Q
cystic fibrosis
A
disorder of cell membrane
->caused by a recessive allele
21
Q
females
A
XX
22
Q
males
A
XY
23
Q
offspring inherits
A
- 1 sex chromosome from mother (X)
- 1 sex chromosome form father(X/Y)
24
Q
variation may be due to the differences:
A
- the genes that individuals have inherited (genetics)
- conditions in which individuals have developed (environment)
25
mutations create
new alleles
26
evolution
gradual change in the inherited characteristics of population over time
27
evolution can lead to
the formation of new species
28
natural selection
-states that all species have evolved from simple life forms that first developed more than 3 billion years ago
29
who thought of natural selection?
charles darwin
30
natural selection occurs because:
- within a species more individuals are born than can survive
- differences in their genes
- individuals with characteristics best suited to environment (more likely to survive)
- > more likely to survive
31
evidence for evolution
- when theory was published, mechanism of inheritance and variation was not known
- now shown that characteristics are passed on from 1 generation to the next by genes
32
fossils
remains of organisms from hundreds of thousands of years ago found in rock
33
fossils formed:
- from the hard parts of animals that do not decay easily
- from parts of organisms that have not decayed, because conditions needed were absent
- when parts of the organisms are replaced by other materials they decay
- footprints
34
scientists use fossils...
to look at how organisms have gradually changed over long periods of time
35
problems of fossils
- earth forms of life were soft bodied
- > left few traces behind
- what traces there were may have been destroyed my geological activity
36
development of antibiotic resistant strains of bacteria
-bacteria can evolve rapidly
-when reproduce mutations occur
-bacteria might be resistant, antibiotics not killed
-bacteria survive + reproduce
—> resistant strain develops
37
steps of selective breeding (artificial selection)
1) chose parents that best show desired characteristics
2) breed together
3) from offspring chose those with desired characteristics
4) continue over many generations
38
selective breeding:
the process by which humans breed plants + animals with particular, desirable characteristics
39
selective breeding characteristics:
- disease resistance in food crops
- animals that produce more meat/milk
- domestic dogs with gentle nature
- large or unusual flowers
40
selective breeding can lead to
inbreeding
- probe to disease
- inherited defects
41
genetic engineering involves
changing the characteristics of an organisms by introducing a gene from another organism
42
genetics engineering is
a more recent way of bringing about changes in organisms
43
in genetic engineering
1) enzymes are used to isolate desired gene
2) gene is inserted into a vector (bacterial plasmid / virus)
3) the vector is used to insert the genes into the required cell
44
fungi and bacteria cells are
genetically engineered to produce useful substances
45
main system way to remember
kid prefer chips over fancy green salads
46
main system
```
kingdom
phylum
class
order
family
genus
species
```
47
new models of classification proposed because:
- microscopes improved (know more about cells)
| - biochemical processes became better understood
48
for evidence there is a
three domain system
49
in tds organisms are divided into:
- archaea
- bacteria
- eukaryota
50
archaea
- primitive bacteria
| - living in extreme environments
51
bacteria
true bacteria
52
eukaryota
nucleus
| protists, fungi, plants + animals
53
extinction is caused by
- changes in environment
- new predators
- new diseases
- new,more successful competitors
- single catastrophic event (volcanic eruption)
54
evolutionary trees
method used by scientists to show how they think organisms are related
