Module 5: Heredity Flashcards
(338 cards)
1
Q
Why is reproduction important?
A
It is a fundamental evolutionary process which has allowed for the continuity of life and species
2
Q
What are the two main types of reproduction?
A
Asexual and sexual
3
Q
What does sexual reproduction involve?
A
Two parents producing unique offspring
4
Q
What occurs in sexual reproduction?
A
The meeting of special sex cells called gametes
5
Q
What is an advantages of sexual reproduction?
A
Provides genetic diversity
6
Q
What is a disadvantage of sexual reproduction?
A
Lots of time and energy required creating vulnerability to predators
7
Q
How many chromosomes do humans have?
A
46 chromosomes arranged in a homologous pair
8
Q
What does diploid mean?
A
2 sets of chromosomes
9
Q
What does haploid mean?
A
1 set of chromosomes
10
Q
What chromosomes do offspring inherit?
A
One set from mum and the other from dad
11
Q
How is a zygote formed?
A
Fusion of haploid gametes
12
Q
What are hermaphrodite?
A
Bisexual animals meaning they have both female and male parts
13
Q
When is hermaphroditism good?
A
For species with low populations or non-mobile species
14
Q
What is a disadvantage of hermaphroditism?
A
Requires a larger amount of energy expenditure
15
Q
Where can fertilisation occur?
A
Externally or internally
16
Q
What is external fertilisation more suited to?
A
Aquatic organisms
17
Q
What is internal fertilisation more suited to?
A
Terrestrial organisms
18
Q
What is done to increase the success of external fertilisation?
A
Synchronisation, mating behaviour and release of a large amount of gametes
19
Q
Does external fertilisation include parental care?
A
No
20
Q
What is an advantage of external fertilisation?
A
Wide dispersal of young
21
Q
What is an example of external fertilisation?
A
Staghorn coral
22
Q
How do Staghorn coral successfully undergo external fertilisation?
A
Shed million of gametes into the sea
Environmental cues help synchronise reproductive cycle
Pheromones also released with gametes to stimulate nearby coral
23
Q
What is the benefit of internal fertilisation?
A
Protects gametes from dehydration and developing young from predators
24
Q
How does reproduction in reptiles occur?
A
Eggs are fertilised internally and then deposited outside
25
What protection do most reptile eggs have?
A soft but tough leathery shell
26
What protection do only a few reptile eggs have?
Some like turtle eggs have a hard shell
27
Where does courtship take place for birds?
In flight or on the ground
28
Where does copulation occur for birds and what is its disadvantage?
Takes place on the ground making them vulnerable to predators
29
How do birds copulate?
Since male birds do not have a penis they instead rub their cloacas together with the female bird
30
What shell forms around bird eggs?
Calcium carbonate shell
31
Do birds show parental care?
They incubate their eggs and exhibit parental care after they hatch
32
What are the three subclasses of reproduction for mammals?
Monotremes, marsupials and eutherians
33
What are monotremes?
Mammals like platypus and echidna that have internal fertilisation and then lay eggs
34
Do monotremes express parental care?
Young hatchlings obtain milk from mammary glands
35
What are marsupials?
Mammals like kangaroos that develop internally for a short time and continue their embryonic development in a pouch
36
What is the reproduction cycle called in marsupials?
Embryonic diapause
37
Why is embryonic diapause beneficial?
It is a strategy to increase chances of survival
38
What are etherians?
Placental mammals such as humans where embryonic development occurs inside the body in the uterus
39
When does a placenta develop?
Once an embryo has implanted into the uterine wall
40
What does a placenta do?
Supplies nutrients and oxygen and removes wastes from the baby
41
What is it called when live young are born?
Viviparous
42
What is it called when young are born from eggs?
Oviparous
43
What is an advantage of eutherian reproduction?
Mature live young are born increasing their chance of survival
44
What does reproduction in plants rely on?
External agents to carry gametes also known as pollinating agents
45
What are the reproductive organs of plants?
Flowers
46
What is the male reproductive system in plants called?
Stamen
47
What are the parts of the stamen?
The anther and filament
48
What is the anther?
Where pollen grains are formed
49
What is the filament?
The stalk that carries the anther
50
What is the female reproductive system called in plants?
The carpel
51
What parts are there to the carpel?
Stigma, style and ovary
52
What is the stigma?
The sticky top surface of a flower to which the pollen adheres
53
What is the style?
It is what joins the stigma to the ovary
54
What is the ovary in plants?
Where the ovules are formed
55
What is pollination dependent on?
Dependent on wind, water and animals
56
What are the two types of pollinations?
Cross pollination and self pollination
57
What is an advantage of cross pollination?
It ensures greater variation in offspring
58
What is an advantage of self pollination?
It requires less energy
59
Which form of pollination is favoured ?
Cross pollination
60
How do plants account for the inefficiency of wind pollination?
Lots of pollen is produced
61
What is one method plants use to reduce pollen wastage?
They use flowers and nectars to attract animals
62
How does fertilisation occur in plants?
Sperm cell by the pollen tube fuses with ovum inside the ovule
63
Where do fertilised ovule develop in plants?
In the ovary
64
What does an ovule become in a plant?
An ovule containing an embryo becomes a seed and the ovary becomes its fruit
65
What are the two main types of fruits produced during reproduction in plants?
Dry fruits and fleshy fruits
66
How do dry fruits increase distribution?
They have explosive mechanism and are light
67
How do fleshy fruit increase distribuiton?
Animals eat them and then discrete the seeds
68
What is germination and when does it occur?
It is when a seed starts growing when it is in good conditions
69
What is a radicle?
A young root which grows during germination that absorbs water
70
What is a plumela?
A young stem that develops during germination and grows green leaves for photosynthesis
71
What does asexual reproduction involve?
One parent required to create genetically identical offspring
72
Where is asexual reproduction most common?
In unicellular organisms
73
What are some advantages of asexual reproduction?
Quick reproduction, competitive advantage if in suitable environment, uses less energy
74
What is a disadvantage of asexual reproduction?
Particularly vulnerable to sudden changes in environment
75
What are vegetative organs?
Organs such as bulbs, tubers, rhizomes and suckers
76
What are perennating organs?
Underground organs such as roots
77
What are the benefits of perennating organs?
Allow plants to survive harsh conditions and when separated give rise to new plants
78
What are runners in plants?
Long, thin, modified stems that grow along the surface
79
What is an example of a plant that uses runners as a method of reproduction?
Strawberries where leaves, flowers and roots are produced at nodes
80
What are rhizomes?
Underground horizontally modified stems
81
What is an example of a plant which uses rhizomes as a method of reproduction?
Ferns
82
What are suckers?
Roots of some plants which produce modified roots known as sprouts
83
What is an example of a plant that use suckers as a means of reproduction?
Blackberry
84
What are apoximis?
Plants that produce offspring from special generative tissue
85
What do apoximis create?
Gametes or leaf tissue
86
What is an example of a plant that uses apoximis as a means of reproduction?
Kangaroo grass
87
What is budding?
When an adult organism gives rise to a small bud
88
What does a bud do once reaching a certain size?
Separates from the parent and grows into a new individual
89
What are some examples of organisms that undergo budding?
Yeast, jellyfish and brain coral
90
What happens as a bud is forming?
The DNA duplicates and then the nucleus divides with one half moving into the bud
91
How long does budding continue for?
As long as there is sufficient nutrients
92
What is an advantage of budding?
If there is no change in the environment it will be highly suited to it
93
What is a disadvantage of budding?
They are not very resistant to change in the environment
94
What is the main method of reproduction for bacteria and protists?
Binary fission
95
What happens during binary fission?
Genetic material is replicated and then split in two
96
What is an advantage of binary fission?
Rapid population growth
97
What is a disadvantage of binary fission?
No genetic variation
98
How does binary fission occur in bacteria?
DNA attaches to opposite ends of the cell membrane and a new cell wall is synthesis in the cell cleavage
99
How does binary fission occur in protists?
Involves mitosis and the formation of a spindle
100
What are spores?
Spores are tiny unicellular reproductive cells
101
What are spores produced by?
Produced by structures known as sporangia
102
What makes spores different to gametes?
They do not have to fuse with a cell to produce an individual
103
What is the structure of a fungus?
Hyphae form the main structure of the fungal body known as mycellium
104
What are spores developed from?
Haploid nuclei
105
What is an advantage of spores?
Extremely light so can be spread wide by wind
106
How do fungus reproduce if conditions are unfavourable?
Sexually
107
What is the purpose of manipulating reproduction in agriculture?
To improve the quality and yield of food
108
What is reproductive technology?
Any use of technology to assist and improve reproduction
109
What can be done with reproductive technology?
Artificial insemination and embryo splitting
110
What are sex hormones responsible for?
The development of reproductive organs
111
What are breeding seasons?
Involves periods of female fertility being limited to once or twice a year
112
What are continuous breeders?
Females that have fertility cycles that repeat throughout the year
113
What are the three main sex hormones?
Androgens, oestrogens and progestogens
114
What are androgens?
Male hormones that control the development and functioning of male sex organs
115
What type of androgen is secreted in the testes?
Testosterone
116
What does testosterone do?
Plays a key role in sperm production
117
What are oestrogens?
Female hormones that control the development and functioning of female sex organs
118
What is the main function of oestrogen?
Ovarian functioning and fertility in females
119
What are progestogens?
Female hormones that play a key role in pregnancy
120
What is the most common progestogen?
Progesterone
121
What do oestrogen and progesterone regulate?
Gamete production in ovaries, preparing the uterus for implantation, menstruation and maintenance of pregnancy
122
What are the two types of gonadotropic hormones secreted by the pituitary gland?
Follicle stimulating hormones (FSH)
Luteinising hormone (LH)
123
What does FSH do?
Stimulates the maturation of follicles in ovaries
124
What does LH do?
Promotes final maturation of ovarian follicle, ovulation and development of corpus luteum
125
When do females get there eggs?
Female babies are born with all the eggs they will ever produce
126
How does an ova mature?
It becomes surrounded by a single layer of cells that begin to divive
127
How often on average does the ovarian cycle repeat?
Every 28 days
128
How does a follicle mature?
Follicle cells secrete fluid pushing eggs to one side of the follicle which then move to the surface creating a bulge
129
What is a matured follicle called?
Graafian
130
What hormone is produced during the follicular phase?
There is a surge in LH production
131
What does the surge in LH lead to in the follicular phase?
Causes ovulation and stimulates the next phase of the ovarian cycle
132
How long does the luteinising phase last?
Around 14 days
133
When does the luteinising phase begin?
After ovulation
134
What happens during the luteinising phase?
The burst follicle enlarges and changes colour building up a yellow protein lutein
135
What is the build up of lutein in the follicle called?
It is called the corpus luteum
136
What does the corpus lutuem do?
Secretes progesterone preparing the body for pregnancy
137
What starts the menstrual cycle?
Day one is menses which is when the lining of the uterus breaks down
138
When does the follicular phase start and end?
Starts on the first day of menses and ends at ovulation
139
What occurs during ovulation?
An egg is released
140
What does progesterone produced by the corpus luteum do?
Prepares the lining in the uterus for implantation
141
What hormones does the placenta produce?
Progesterone, oestrogen and HCG
142
What does LH stimulate in males?
The production of testestrone
143
What does FSH stimulate in males?
The production of a protein to maintain testestrone levels
144
What does the hormone inhibin do in the male reproductive cycle?
Reduces levels of FSH in the body
145
Where and how are sperm produced?
Produced by meiosis inside sperm tubules in the testes
146
What is the structure of a sperm?
Sperm head contains a haploid nucleus and long tail moves side to side
147
How many sperms enter the female reproductive system?
Half a million
148
How long can sperm survive in the female reproductive system?
For a couple of days
149
How are sperm attracted to the egg?
By rheotaxis which is the movement through fluid
150
What are the three layers of the egg a sperm has to get through?
Corna radiata, ona pellucida, cell membrane
151
What prevents other sperms from entering the egg after one has already penetrated it?
Surface proteins
152
What is a fertilised egg called?
A zygote
153
What happens to the corpeus luteum when a zygote implants?
It continues to grow and secreting hormones
154
When does the placenta do after three months?
It takes over the role of secreting hormones
155
When does the ovarian cycle usually resume after pregnancy?
After the mother stops breastfeeding
156
What does the placenta do?
Carries oxygen and nutrients from the mother to foetus and removes waste
157
What are the two things that must occur for birth to occur?
Uterus contractions and the tissue of the cervix must soften so that it can dilate
158
What hormones initiate labour?
Prostaglandins secreted by the uterus wall
159
What does oxytocin promote during labour?
Coordinated contractions and softens the cervix
160
What does relaxin do during labour?
Further aids in the softening of the cervix
161
What does the decrease of progesterone and oestrogen do during labour?
Promotes stronger contractions
162
What is mitosis responsible for?
Growth of multicellular organisms, repairing damaged tissue, asexual reproduction and genetic stability
163
What does meiosis result in?
Formation of gametes
164
What are the two parts of meiosis?
Meiosis 1 - diploid cell divides into haploid cells with half chromosomes
Meiosis 2 - cell divide again resulting in four haploid cells
165
What are the five main phases of the cell cycle?
G1 - gap phase for cell growth before DNA replication
S - synthesis during which DNA replicates (interphase)
G2 - second gap phase when enzymes check duplicated chromosomes
Mitosis - division of the nucleus
Cytokinesis - separation of the two cells
166
What are the four phases of mitosis?
Prophase, metaphase, anaphase and telophase
167
What occurs during prophase?
DNA separates into chromosomes containing two copies of DNA
168
What occurs during metaphase?
Chromosomes line up in the centre and spindle fibres attach
169
What occurs during anaphase?
Sister chromatids separate to opposite ends of the cell
170
What occurs during telophase?
Chromosomes gather on opposite ends of the cell and the nuclei form
171
Where else can DNA be found that is not in the nucleus?
In organelles such as mitochondria and chloroplast
172
When do organelles replicate?
After cell division they replicate independently
173
Who was the first scientist to identify DNA?
Miescher
174
What did Watson and Crick use to construct the DNA model?
Chemical and X-ray evidence
175
What is the Watson and Crick DNA model?
Two stranded molecules with paired bases twisted into a helix
176
What did crick realise about the backbone?
That the sugar phosphate backbone is antiparallel to the other
177
What are the two pairing options of bases?
Adenine (A) - Thymine (T)
Guanine (G) - Cytosine (C)
178
What holds the DNA strands together?
Weak hydrogen bonds
179
What are the two types of nucleic aicds?
DNA and RNA
180
What chemicals are in nucleic acic?
Carbon, hydrogen, oxygen, nitrogen and sometimes phosphorus
181
What are nucleic acids?
Polymers made from monomers called nucleotides
182
What is a nucleotide made from?
Ribose (RNA) or deoxyribose (DNA), phosphorus and nitrogen
183
What is DNA and what does it do?
Main chemical in the nucleus that stores genetic info that controls the cells and is responsible for transmitting inherited information
184
What is RNA?
Is a nucleic acid found in small amounts in the nucleus and in large amounts in the cytoplasm
185
What is a key difference between RNA and DNA bases?
RNA has the base uracile (U) instead of thymine (T)
186
What are the three types of RNA?
Messenger RNA - mRNA
Ribosomal RNA - rRNA
Transfer RNA - tRNA
187
What does mRNA do?
Carries info from the DNA to the cytoplasm
188
What does rRNA do?
Brings mRNA and tRNA together during translation
189
What does tRNA do?
Translates mRNA messages into proteins
190
What is the first step of DNA replication?
Helicase causes the DNA helix to progressively unwind
191
What is the second step of DNA replication?
DNA unzips from the bottom creating a replication fork exposing the nucleotide bases
192
What is the third step of DNA replication?
A primer attaches to the DNA and DNA polymerase III adds nucleotides to continue the synthesis
193
What are the two strands of DNA doing?
They run antiparallel and have either a 3' end or 5'end
194
From where are nucleotides always added?
From the 3' end
195
What is the leading strand and how are nucleotides added to it?
They end with 3' end so nucleotides are added in long chains
196
What is the lagging strand and how are nucleotides added to it?
They end with 5' end so nucleotides are added in chunks
197
What are the chunks added to the lagging strand known as?
Okazaki fragments
198
What does the enzyme ligase do?
Forms one continuous strand of the lagging strand
199
What is the fourth step of DNA replication?
Replication errors are identified and corrected by DNA polymerase I
200
What are natural errors in DNA replication known as?
Spontaneous mutation
201
What are errors in DNA replication caused by exposure to the environment called?
Mutagenic mutations
202
What are environmental factors that cause errors in DNA called?
Mutagens
203
What is DNA mismatch repair?
When polymerase I recognises mismatched base pairs and replaces them correctly
204
What can be the effects of mutations?
They can be harmful, beneficial or have no impact
205
Why is accurate replication of DNA important?
As the genes code for proteins that determine the functioning of the cell
206
What are 5 mechanisms to ensure genetic continuity?
Consistent replication before cell division
Orderly distribution of chromosomes
Successful fertilisation methods
Methods to ensure embryo survival
Natural selection
207
What are 2 mechanisms for genetic variation?
Mutation
Mixing of parental genes
208
What is the DNA like in prokaryotes?
Contain a single chromosome in a circular strand called a nucleoid
209
What non-chromosomal DNA do prokaryotes have?
One or more small rings of non-chromosomal DNA known as plasmids
210
What do plasmids do?
Code for features that are not essential to the survival of the cell
211
What is the structure of the DNA in prokaryotes?
Supercoiled and forms loops around a central protein
212
What is non-coding DNA known as?
Introns
213
What is coding DNA known as?
Exons
214
What is the structure of the DNA in eukaryotes?
Is linear and is wrapped around five main proteins known as histones
215
What are polypeptides?
Molecules made up of a chain of amino acids
216
What is transcription?
Process of creating RNA using RNA polymerase
217
What is the first step of transcription?
Part of the DNA unzips and the non-coding strand has the info for the protein
218
What is the second step of transcription?
The non-coding strand acts as a template for the mRNA to assemble
219
What is the third step of transcription?
The mRNA moves out of the nucleus and to the ribosomes
220
What is translation?
The synthesis of the polypeptide sequence from mRNA
221
What is the first step of translation?
Ribosomes move along mRNA and temporarily attach to tRNA
222
What is the second step of translation?
Amino acids on tRNA are linked by an enzyme forming a polypeptide chain
223
What is the third step of translation?
tRNA moves away from mRNA leaving a growing polypeptide chain
224
What is the fourth step of translation?
Polypeptide chain is processed and created into the final protien
225
What is the fifth step of translation?
mRNA is broken down to be reused
226
What is the shape of tRNA?
Clover leaf shape with at one end three unpaired bases called anticodons
227
How do tRNA work?
An anticodon attaches itself to its complimentary bases on the mRNA and an amino acid binds with the other end depending on the anticodon
228
What is the analogy for protein synthesis?
DNA is the operating system, mRNA is the software, tRNA is the machinery and the protein is the product
229
What is non-coding DNA responsible for?
It determines whether or not genes are read depending on how tightly its is wrapped around histones
230
What is phenotype?
The physical appearance, structure, behaviour and physiology
231
How can phenotype be influenced?
Can be influenced by genetics or factors in the environment
232
What is an example of a phenotype influenced by the environment?
Hydrangeas are different colours according the pH of the soil they are in
233
What colour are hydrangea flowers when in acidic soil?
Blue
234
What colour are hydrangea flowers when in basic soil?
Pink
235
What is the primary structure of proteins?
Arranged in linear chains
236
What is the secondary structure of proteins?
3D arrangement linked by hydrogen bonds
237
What is the tertiary structure of proteins?
More complex 3D arrangements
238
What is the quaternary structure of proteins?
2 or more polypeptide chains that are linked
239
What do fibrous proteins do?
Form structural components of cells and tissues
240
What is the structure of fibrous proteins?
Long and insoluble in water
241
What are some examples of fibrous proteins?
Collagen, elsatin, keratin
242
What is the structure of globular proteins?
Spherical in shape and compact and soluble in water
243
What is an example of a globular protein?
Haemoglobin
244
Where can structural protein be found?
In connective tissue like skin, bone and tendons
245
What do enzymes do?
They are involved in cellular metabolism and catalyse reactions such as chemical respiration and digestion
246
What do channel proteins do?
Regulate the intake and output of chemicals such as sodium ions
247
What do receptor proteins do?
Receive signals sent by hormones and neurotransmitter and act as markers allowing the body to recognise itself as self
248
What happens during crossing over?
Arms of pair of homologous chromosomes wrap around each other
249
What are the points of crossing over of chromosomes known as?
Chiasmata
250
What occurs at the chiasmata?
Arms of the chromosome break and exchange material
251
What are punnet squares?
A model used to represent inheritance
252
What can punnet squares be used for?
To predict possible outcomes
253
What is a test cross used for?
To determine the genotype of a phenotypical dominant thing as it can either be homozygous or heterozygous
254
What is a pedigree?
Traits expressed in a family over several generations with a minimum of three studied
255
What can a pedigree be used for?
To study the heredity patterns in families
256
What is the key usually to a pedigree?
Male - square
Female - circle
Trait present - shaded
257
What type of numbers should be assigned to each generation in a pedigree?
Roman numerals I, II, III
258
What type of numbers should be assigned to each individual in a generation?
Normal numbers 1, 2, 3
259
What makes a zygote female?
When an X chromosome is inherited from both parents
260
What makes a zygote male?
When an X chromosome from the mum and a y chromosome from the dad is inherited
261
What is sex linkage?
When the X and Y code for not only gender
262
Which chromosome X or Y can carry the allele?
X chromosome
263
In what gender do recessive disorders occur in more frequently?
In males
264
What is it called when an allele is present but not expressed?
A carrier
265
What is incomplete dominance?
The blending of features of the two alleles expressed
266
What is the notation for incomplete dominance?
A letter chosen for the gene and the allele is a subscript in the right top corner
267
What is codominance?
When both alleles are expressed creating a new phenotype
268
What is the notation for codominance?
Same as incomplete dominance but each allele is written with capital letters
269
What does multi-allelic mean?
When there are three or more alleles for a single gene trait
270
What is an example of multi-allelic trait?
Human blood type that has three alleles A, B and O
271
What is the dominance of the alleles for human blood?
A and B are codominant as markers are produced on RBC and and O is recessive as no markers are produced on RBC
272
What is population genetics?
Study of how the gene pool of the population changes over time
273
What is the gene pool?
Is the sum total of all the genes and alleles with a population
274
How can allele frequency be measured?
Number of copies of allele G in the population/ total copies of the gene G + g in the population
275
What does SNP stand for?
Single nucleotide polymorphisms
276
What does SNP refer to?
Individuals with different phenotypes
277
Where do most SNPs occur?
In the non-coding region hence are not observable
278
Why are SNPs important?
They are genetic markers used to distinguish individuals and can be associated with disease and disorder
279
What is genotyping?
Involves identifying genetic variation in individuals
280
What is sequencing?
Involves finding the exact nucleotide sequence
281
What is the sanger method?
A method for DNA sequencing
282
What is the sanger method known as?
dideoxy DNA (ddDNA) sequencing
283
What are the steps in the sanger method?
Isolate DNA from the cells, undergo the sequencing reaction, sort DNA fragments by length using capillary electrophoresis, analyse results using a computer
284
What is the maxam-gilbert method?
A method for DNA sequencing
285
What does the maxam-gildert method involve?
The chemical sequencing of DNA strands
286
Why is the maxam-gilbert method not used widely?
Due to its complex nature and its hazardous chemicals
287
What is DNA profiling also known as?
DNA fingerprint analysis
288
What is DNA profiling used for?
To identify and compare individuals by their DNA
289
What is DNA profiling a useful tool for?
In forensic investigations and paternity testing
290
What does PCR stand for?
Polymerase chain reaction
291
What does PCR do?
It increases the amount of DNA for testing
292
What is an ethical consideration of DNA sequencing?
Who owns the information once analysed
293
How do you know if an allele is sex linked dominant?
If a dominant father has female offspring with dominant traits
294
What base does uracil pair with?
Adenine
295
Is an artificially cloned mammal completely genetically identical?
No as there is DNA from the donated egg and the donated somatic cell
296
What type of response is sweating?
A nervous response
297
What type of response is vasodilation?
A nervous response
298
The rupture of an ovarian follicle occurs after a surge in which hormone?
Luteinising hormone (LH)
299
What is the response of an Australian plant to a named pathogen?
Basket grass responds to Phytophthora cinnamomi which is a fungus by producing hydrogen peroxide, reinforcing the cell wall and plant cell death to limit the spread
300
What is DNA sequencing?
Provides the order of bases and pairs
301
What is DNA profiling?
Gives information about the relatedness of an organism to other organisms
302
What is the main role of proteins?
To provide structure and support for cells
303
What does autosomal mean?
That the gene in question is located on one of the numbered chromosomes
304
Why is the process of polypeptide synthesis important?
It leads to the correct sequence of amino acids in polypeptides and proteins
305
What is population genetics?
The study of genetic variation within a population
306
What factors affect the gene pool?
Size population
Mutation
Natural selection
Genetic drift
Diversity of the environment
Migration patterns
307
What was used to compare koalas?
Haplotypes
308
What are haplotypes?
A group of SNP markers used to compare organisms
309
What is a monogenic disease?
A disease from a single gene in all cells of the body
310
What are polymorphisms?
When individuals have different phenotypes usually due to mutations
311
What is the newborn screening program?
Free genetic testing for newborns for SNPs associated with congenital diseases
312
What are the two main theories for human migration?
Multiregional hypothesis
Replacement hypothesis
313
Which theory is correct and what is the evidence?
Genetic studies have shown the multiregional hypothesis is correct
314
What are mutagenic agents?
Agents which alter DNA and cause mutations
315
What are some examples of chemical mutagens?
Ingested chemicals such as alcohol and environmental such as solvents
316
What do chemical mutagens do?
They are structurally similar to DNA bases and may be incorporated resulting in incorrect insertion of nucleotides
317
What are natural muatgens?
Mutagens present at normal level in the environment
318
What are biological muations?
Mutagens which are naturally occurring such as viruses and bacteria
319
What are non-biological mutations?
Mutagens which are naturally occurring such as metals
320
What is the arrangement of DNA in prokaryotic cells?
Single loop of DNA no nucleus
321
What is the arrangement of DNA in eukaryotic cells?
Strands of DNA in a nucleus
322
What is the role of progestrone?
Keeps the placenta functioning, maintains the uterine lining, regulates blood sugar levels, stimulates the growth of mammary
glands
323
How does progestrone levels change throughout pregnancy?
Normally rises during the first 36–38 weeks of the pregnancy, then fall towards the due date
324
What results in new alleles?
Mutation in the DNA gene
325
What does crossing over and and random segregation during meiosis lead to?
Creates new combinations of alleles, genetic variation
326
Where can mitochondrial DNA be inherited from?
Only females
327
How does mitosis contribute to continuation of species?
Mitosis assists the continuity of species by allowing growth and repair as well as asexual reproduction
328
What is independent assortment?
Homologous chromosome pairs are separated into daughter cells independently
329
What is random segregation of alleles?
During meiosis each parent passes an allele at random to their offspring resulting in a diploid organism
330
How is fertilisation important to the continuation of species?
Is essential for sexual reproduction
Involves the genetic input of of two different parents creating genetic diversity
331
Why is genetic diversity important?
It is important for natural selection and evolution in changing environments
332
Why is implantation important to the continuation of species?
It is important for placental mammals as it allows internal development so that young are born relatively developed
333
Why is hormonal control of pregnancy important to the continuation of species?
It ensure that the foetus is born when it has developed sufficiently to allow its survival
334
What does the hormone relaxin do?
Allows the expansion of joints and muscles of the mother
335
How many people in a population must have a SNP for it to be counted as an SNP?
At least 1% of the population
336
What is the larger structure in DNA?
Deoxyribose sugar
337
What is the smaller structure in DNA?
Phosphate
338
What is the function of proteins?
Are responsible for the functioning of cells as enzymes catalyse reactions
