Biology Module 5 - Heredity Revision Flashcards
(117 cards)
1
Q
Why do we need reproduction?
A
For the continuity of species as we have finite lifespans.
2
Q
Asexual Reproduction and methods.
A
Individuals who create exact copies of their genetic material, replicated through mitosis.
Methods: Budding, Binary/multiple fission, spores.
3
Q
Sexual Reproduction
A
Occurs between 2 genetically different parents, where their haploid gametes fuse into a zygote, creating a variation through their offspring.
4
Q
Reproductive Success
A
Producing fertile offspring to survive reproductive maturity and produce offspring of their own.
5
Q
Biological Fitness
A
To contribute to the gene pool from a certain genotype where their allele/gene variant is present in the future.
6
Q
Biological Fitness (Simple definition)
A
The more offspring you produce, the better your biological fitness.
7
Q
How to ensure success for gametes to meet.
A
The ovum and sperm should be in a moist environment at close proximity. Dehydration kills/falters performance of gametes.
8
Q
Methods of Aquatic and terrestial organisms ensuring gamete fusion.
A
Aquatic/amphibian organisms breed in mating rituals in the ocean.
Terrestrial organisms release internally due to the lack of environmental moisture.
9
Q
3 Mammal types
A
Monotreme - Lays eggs
Marsupial - Stores young in pouch
Placental - Develops from placenta nutrients
10
Q
External Fertilisation
A
Occurs openly by aquatic animals.
- Parents releases mass gametes for highest chance of fertilisation.
- Usually done in mating rituals to ensure proximity at a concentrated area.
11
Q
External Fertilisation - Example
A
Sessile (non-moving) animals such as oysters and coral have mass spawnings (usually full moon, high tide - natural phenomena) as a mating ritual for fertilisation.
12
Q
External Fertilisation - Positives
A
Fast, prolific development, using minimal energy and females can still produce during development. Young disperse naturally reding infraspecific competition.
13
Q
External Fertilisation - Negatives
A
Excess use of gametes with limited success, requiring mass gametes exposed to predators, disease, currents and environment generally.
14
Q
Internal Fertilisation
A
Parents produce from copulation after courtship is achieved, male inserts penis (mammals/reptiles) to release gamete to fertilise ovum. A zygote is formed from the fusion.
15
Q
Internal Fertilisation - How do insects attract mates.
A
Produce ‘pheremones’ to attract mates.
16
Q
Internal Fertilisation - Courtship
A
Emotional connection, needed for; Flat/earthworms, insects, reptiles, mammals and birds.
17
Q
Internal Fertilisation - Advantages
A
High success from inclosed proximity of less gamete use, young are protected and given nutrients internally for survival.
18
Q
Internal Fertilisation - Disadvantages
A
Requires courtship, slow development with mass energy use by female and young is cared for after birth.
19
Q
Maternal, Paternal - Vertebrates, Invertebrates
A
Maternal - Mother
Paternal - Father
Vertebrate - Backbone
Invertebrate - No Backbone
20
Q
Human Chorionic Gonadotrophin
A
Stimulates the corpus luteum (later placenta) to make progesterone for pregnancy.
21
Q
Lutenising Hormone
A
Stimulates testes to create testosterone.
Assists progesterone release after ovulation via the corpus luteum.
22
Q
Where is HCG, FSH & LH made?
A
The Piturity Grand in the brain creates HCG to then create FSH and LH.
23
Q
Oestrogen
A
Primary, involved with secondary sex characteristics (puberty) in females.
Thickens the endometrium and lubricates vagina in menstrual cycle.
Matures Sperm.
Develops baby organs and functions the placenta.
24
Q
Progesterone
A
Surrounds the Cervix and uterus for acrosomes to climb and reach the ovum.
If implantation is successful, the corpus grows to then be replaced by the placenta, failure cause it to degenerate.
25
Progesterone (Simple Definiton)
Supports menstruation and maintains the early stages of pregnancy.
26
Androgen
Secondly Sex Characteristics for males.
involved in the initiation and maintenance of spermatogenesis.
27
Oxytocin
Stimulates uterine contractions during labour as well as breastmilk flow after birth.
28
Relaxin
Relaxes muscles, ligaments and joints for the growing foetus, stretches the body.
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Endorphin
Relieves pain to increase concentration for labour.
30
Features of Fertilisation - General
Requires gametes to meet and combine - created originally from Gametogenesis.
Fertilisation occurs in the fallopian tube, creating a zygote from fusion - continuity through variation.
Stages for successful fertilisation.
- Formation & maturation of gametes
- Spermatozoa must journey in the oviduct
- Spermatozoa fuses through contact with ovum
31
Features of Fertilisation - Male
Needs spermatogenesis, assisted by testosterone (made in testes, assists in production) and oestrogen (assists in maturing cells)
32
Features of Fertilisation - Process in female
Acrosome will detach from the flagellum to journey up the uterus.
Passes through 3 barriers of the egg (corona radiate, zona pellucida and then egg membrane (follicle cells still attached act as enzymes, assisting sperm to cross).
Only 1 sperm enters, electric current prevents others. The final fusion creates successful implantation.
Cell division begins to form a blastocyst, gametes must be of the same species.
33
Features of Implantation
The zygote sticks to the wall of the reproductive tract as the most suitable environment.
The blastocyst implants to the uterine wall to access nutrients and develop into an embryo - blood vessels surrounding blastocyst carries blood with dissolved nutrients.
Embryo develops into a foetus after 5-11 weeks.
Embryo becomes a new organism after birth.
34
Plant Reproduction - Male, Female and no-gender reproductive parts.
Male parts/Stamen
Anther: Where pollen forms
Filament: Stalk holding the anther
Female parts/Pistil
Stigma: Sticky surface to catch pollen
Style: Binds the stigma to ovary.
Ovary: Holds/forms ovules here
Ovule: Organ that forms seeds (flowing plants)
No-gender:
Petals: Modified leaves to attract pollinators.
Receptacle: Reinforced the base supporting reproductive structures.
Sepals: Modified green leaves that protect unopened flowers/buds.
35
(Flowering) Plants - Sexual Reproduction
When pollen sticks to the stigma, it travels down the newly formed pollen tube to fuse with the ovule - creates an embryo/seed with its exterior developing into a fruit.
After fertilisation, seeds will disperse from the ovary, either as dry of fleshy fruits.
36
Plants - Dry and fleshy fruits
Dry fruits (banksia, pinecones) use explosive mechanisms to disperse seeds over time.
Fleshy fruits (apple) require a biotic agent to eggiest seeds for dispersal.
37
Plants - Cross and Self pollination
Cross pollination brings one plants pollen to another creating variation.
Self pollination uses less energy and no pollinators, producing through mitosis.
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Plants - Angiosperms and Gymnosperms
Angiosperms are flowering plants. Most are wind pollinated - small , green, odourless, petal less flowers in large numbers with light pollen to travel - highly inefficient.
Other variants use pollinating agents - Like bees, they are attracted to rewards (nectar), pollen attaches to the pollinating agent and makes contact to another stigma due to it.
Gymnosperms have no flowers, with seeds being directly expose (cones). Microspore from male cone will enter female in the pollen tube to reach the megaspore in the ovule, once fertilised the variation is formed and dispersed.
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Plants - Germination
The embryo is dormant and dehydrates to survive varying conditions. It will germinate when it finds; nutritious soil, water and warmth. Creating a Radicle Root for water/nutrients then a Plumute for photosynthesis to then develop further.
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Plants - Asexual Reproduction: P/N and Vegetative Organs
Done by organisms well adapted, disadvantages in how offspring are identical, great risk of eradication.
Some vegetative organs include:
Stolons: Strawberries (Develop plantlets)
Rhizomes: Ginger
Bulbs: Onions (storage organ)
Tubers: Potatoes
Suckers: Roses
Regeneration and Fragmentation: Sea Sponges (Part breaks off and grows new individual (cuttings))
Spores: Mushrooms
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Plants - Peremating Organs
Roots/stems which store nutrients in a large dormant wooden vessel to survive adverse conditions by seasons until safe to develop/regrow.
42
Reproduction - Fungi Definition
Eukaryotic organisms that secrete enzymes to break organic matter and absorb nutrients (mushroom, yeast, moles, truffles), releasing; carbon, nitrogen, oxygen, phosphorous.
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Reproduction - Fungi reproduction process
1. The sporophores use mitosis (sometimes meiosis for instant variation, depends on species) to release spores that grow without fertilisation.
2. Mycelium does mitosis to extend roots, releasing pheromones to attract other roots.
3. Plasmogamy occurs (2 cytoplasm combine, holding 2 nuclei) in the heterokaryotic stage. Gametangia is made needed for gamete production for new fungi.
4. Karyogamy occurs, fusing nuclei into a zygote - then grows over years.
5. Zygote creates a sporangia to germinate from mitosis and create a new mycelium network, until forming a sporophores from continuous budding. - Variation is created.
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Reproduction - Fungi Heterokaryotic stage
When the one cytoplasm stores 2 genetically different nuclei.
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Reproduction - Protists Definition & Reproduction
Eukaryotic living in moist environments. 'Biological junk drawer of cells that don't make tissue.
Can complete Binary fission too.
Multiple Fission (in unfavourable conditions)
1. Parent creates a cyst
2. Nucleus divides numerous times, producing multiple daughter cells.
3. Each daughter gains equal cytoplasm then wrapped in membrane.
4. Disperse from cyst when safe.
46
Reproduction - When do protists develop sexually?
Only produces sexually when under stress. E.g. Paramecium will use conjugation to create micronuclei with another, making variation to adapt and survive.
47
Reproduction - Bacteria Definition and Reproduction
Prokaryotic organism. Binary fission isn't mitosis since no nucleus is involved.
Binary Fission (asexual)
1. Nucleoid elongates to opposite poles as organelles & genetic material duplicate and are pulled accordingly.
2. Cleavage furrow begins to form as cell wall & membrane do cytokinesis in it with cell splitting creating 2 cells.
Process is exponential and quick.
48
Reproduction: Genetic Recombination & 3 variations
Rearrangement, breakage and rejoining of chromosomes segments, changing DNA sequence.
Transduction: A virus hijacks bacteria where its genes are incorporated into the genome of the virus. Imprecise and makes host break down as virus reproduces internally and then disperses to change other bacteria (bacteria doesn't die).
Conjugation: 2 of same species contact temporarily via pills tube, exchanging genetic material. Donor must have F-plasmid that recipient lacks, form of sexual reproduction too.
Transformation: 'Competent' bacteria ingest naked DNA from the environment absorbing into its chromosomes. (Competence is a genetic ability that genes must activate).
49
Agriculture - Plant Propagation
Asexual propagation from grafting; combining traits manually by fragmentation then wrapping the 2 stems together. Creates lack of genetic diversity, but produces same reliable traits - susceptible.
Sexual propagation from selection and germination from seed banks creates more diversity and still lets us create select traits - Palatability, disease resistance, storage size, quantity for agricultural production.
50
Agriculture - Animal Reproduction
Selective breeding raises concerns in poultry and ethics of animal welfare.
Artificial Insemination (AI) collects, stores and transports sperm of desire for manual fertilisation.
- Milk/meat selected traits are reducing fertility, dairy performance and reproductive ability in cattle.
Cloning: Nucleus of somatic cell is placed in an egg. Dolly the Sheep (1996). Creates lack of diversity and susceptibility to disease and genetic disease; hip dysmorphia in dogs.
Multiple Ovulation and Embryo Transfer (MOET): Cattle is fertilised and implanted, after 7 days, egg is taken and implanted into other cattle to then fully produce.
- Excess hormone treatment and procedure of MOET creates abnormality from offspring increase.
51
Parthenogenesis and process
Virgin Birth: (Honey Bees and Ants) Create female gametes and develop offspring without fertilisation.
Process:
The egg doubles and divides genetic material before the cells & genome fuse with 2 sets of identical chromosomes from the 'mother' for the offspring to then develop.
52
Homothallic and Heterothallic Definition
Homothallic: Self-fertile, produce sexually from a single spore for new colonies.
Heterothallic: Requires haploid a and a cells to fuse to produce new individuals.
53
Ascus and Ascospores Definition
Ascus is a sac where spores of fungi develop.
Ascospores is a spore formed within an ascus.
54
Syngamy
2 complete fusions of a haploid gamete that creates new diploid organisms for Protists.
55
Conjugation for protists
Temporary union of 2 individuals to exchange haploid pronuclear to form a zygote nucleus. The individuals then produce daughter cells by binary fission.
56
What does DNA consist of?
Sugar Phosphate backbone, nucleotide and hydrogen pulls.
An individual nucleotide is made of a phosphate, deoxyribose sugar and nitrogenous base.
57
Nature of antiparallel DNA and base bindings
each strand of DNA has a 5' and 3' end, antiparallel means that the strands travel in opposite directions.
Purine base Adanine binds to pyrimidine base Thymine.
Purine base Guanine binds to pyrimidine cytosine.
58
DNA vs RNA
DNA holds genetic info and controls cells, its found in the nucleus, mitochondria and chloroplasts.
RNA is barely found in the nucleus/nucleolous, more in cytoplasm and ribosomes (uses uracil instead of thymine).
3 RNA variants: mRNA, tRNA, rRNA
59
DNA Replication process
1. Gyrase relaxes supercoiled DNA.
2. Helicase cuts through the strands in the middle, unwinding and separating hydrogen bonds.
3. Primase binds RNA primer to strands to begin replication. A short complementary RNA molecule is synthesised onto the DNA to mark the start point.
4. DNA polymerase III synthesis's new DNA strands using existing strands.
5. DNA polymerase I edits; recognise and repair pairing errors in exonuclease.
6. DNA polymerase II repairs nucleotide sequence mistakes.
7. Ligase connects/seals 2 strands of DNA and connects Okazaki fragments.
60
Spontaneous and Mutagenic mutation definitions
Spontaneous mutations are natural errors in DNA replication.
Mutagenic mutations are caused by environmental exposure; radiation, chemicals and virus's.
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Genetic expression
The fact that genetic material should be transmitted accurately with correct instructions to ensure correct structure, functioning and behaviour for survival.
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IPPMATC
Interphase, early Prophase, late Prophase, Metaphase, Anaphase, Telophase, Cytokinesis
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The cell cycle
Phases
G1: Cell growth
S: DNA synthesis
G2: Growth and prep for mitosis
M: Mitosis
(interphase occurs between G1, S & G2)
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What is Mitosis
The duplication of a cell for growth, repair and replacement on somatic cells.
65
Mitosis procedure
Interphase: [Prior] the cell grows while chromatid replicate.
Prophase: Centrioles move to opposite poles as spindle fibres stretch between ends as mitotic spindles organise chromatid.
Metaphase: Spindles attach to centromeres of chromatid at equator.
Anaphase: Centromeres divide with new chromosomes, distributing.
Telophase: Cytoplasm splits in 2 as 2 new daughter cells are formed.
66
What is Meiosis's purpose?
To create variation in sex cells for adaptability/continuity of species.
67
Law of Segregation
Only 1 of the 2 gene copies in an organism is distributed to each gamete at equal chance for offspring to inherit.
68
Independent Assortment
Allele of a gamete received had no bearing on the allele received from another gene, equally likely to receive recessive or dominant alleles as a result of meiosis.
69
Crossing Over
When alike paternal & maternal chromosomes align to swap genes and alleles out to create variation.
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Meiosis Procedure (1/2)
Prophase 1: Chromosomes condense and form tetrad chromatids as crossing over occurs.
Metaphase 1: All material moves to the equator, chromatids attached at centromere by spindle fibres.
Anaphase: New sister chromatids unbind from tetrad but remain intact when moving, seperase enzyme is blocked by shugoshin protein.
Telophase 1: Chromatids migrate to opposite poles before cytokinesis forms 2 new cells.
71
Meiosis Procedure (2/2)
Prophase 2: Nucleolus disintegrates and chromatids short and thicken while centrosomes replicate & migrate to opposite poles.
Metaphase 2: Same chromatids align at equator.
Anaphase 2: Sister chromatids split and move.
Telophase 2: The 2 cells split producing 4 haploid cells, male sperm still needs to develop flagellum.
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Transcription Procedure
1. RNA polyermase binds to DNA strand after gyrase seperate portion of DNA.
2. The sense strand is used to create a complementary mRNA strand.
3. mRNA moves out of the nucleus into the cytoplasm to encounter ribosomes
73
How is the Pre-mRNA strand modified for polypeptide synthesis?
Modified to only use necessary sequences, non-coding regions/introns are spliced as exons merge together to fill in the gaps.
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Translation Procedure
1. Ribosomes attach to mRNA and tRNA attaches too.
2. tRNA reads the mRNA, attaching Amino acids on the tRNA tail link to one another forming a polypeptide chain.
3. tRNA moves away to find new amino acid.
4. Polypeptide chain is processed and joins other chains to fold and form protein.
5. mRNA breaks down to nucleotides for reuse.
75
How do genes and the environment affect phenotype?
From Diet (availability of food/water), pH level of soil, Temperature and Mutations.
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Example of: Genotype + Environmental factors = Phenotype
Rats licking their babies is an environmental factor, switching genes on/off affecting behaviour - this will continue licking trend to the future creating happy rats.
Genes also change for unlicked rats but a negative neglectful outcome.
77
Dominant & Recessive allele rules
Dominant over Recessive always
Same letter for same traits
2 dominant alleles = dominant
1 dominant 1 recessive = dominant
2 recessive = recessive
78
Mutations
Alters allele identity due to DNA sequence changes - point mutation. Occur in germ cells.
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Autosome
A chromsome in an organism that is not a sex chromosome, most Punnett squares are for autosomal chromosomes.
80
Pedigree chart rules
Circle = Female
Square = Male
Diamond = Unknown
Fully shaded = Affected individual
Half shaded = Carriers
Horizontal lines connect symbols for mating, vertical for offspring.
Numbers are used to distinguish siblings of each generation.
81
What are Polymorphisms and SNP's
Present in 2 alleles for a gene in 1% of the population p every 100-300 nucleotides. Accounts for 90% of genetic variation.
Single Nucleotide Polymorphisms (SNP) affects 1 nucleotide an individuals genome, randomly replacing an existing nucleotide - single nucleotide substitution.
82
The impact of SNP's
They alter DNA sequences, creating new alleles, roughly 99% occur outside the coding regions, non-coding SNP's may influence disease susceptibility. Affects physical, physiological and behavioural traits.
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Types of SNP's
Coding SNP's: In gene regions.
Synonymous SNP's: Codon changes, amino acids remain the same.
Non-Synonymous SNP's: Codon changes, amino acids are altered.
Mis-sense SNP's: Altered codon specifies a different amino acid.
Non-sense SNP: Altered codon specifies a premature stop codon.
84
Limits of SNP's
Genotype alone doesn't determine phenotype, environmental factors can influence trait expression, diseases may be monogenic or multigenic.
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Purpose of conservation studies and management
To maintain species adaptability to changing environments, studies allele frequency changes due to environmental conditions or migration.
86
Multi-regional Hypothesis
Proposes that Homo Erectus evolved independently with gene flow and modern humans evolved with gene flow, resulting in similar appearances.
87
Replacement Hypothesis
(Out of Africa) Home Erectus originated in Africa and dispersed 100,000yrs ago, modern humans evolved from Africa Homo Erectus out competing others.
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Bottleneck
An event drastically reducing the variation of a species - global event, like liquid coming out of a bottle, its held at a choke point.
89
DNA sequencing and profiling
They both offer distinct advantages based on research objectives. Sequencing provides precise nucleotide order while profiling shows genetic variations and is effective in forensic paternity and population genetic investigations.
90
Why are men more likely to have sex linked traits compared to women?
Men only get sex linked traits on their X allele (not y), while women have 2 X alleles. Sex linked traits are recessive so women can counter that.
91
Can sex linked traits be on both alleles of a women? What about men?
Yes, if both parents have the recessive trait and pass it down, if men have even 1 recessive trait, they automatically get the disease.
92
Difference between coding and non-coding SNP’s
Coding occurs in the DNA (gene) where proteins are coded.
Non-Coding occurs outside the DNA
93
SNP
Single Nucleotide Polymorphism
94
What does a synonymous SNP do?
Synonymous SNP’s change the base of a coding sequence, but doesn’t change its protein/amino acid coding sequence, because the altered gene sequence from SNP’s changed the mRNA codon- still coding the same sequence.
95
What do Non-synonymous SNP’s do?
The opposite of synonymous, the amino acid coding sequence is changed, changing the coded protein’s required amino acid - may be nonfunctional now.
96
Mis-sense and Non-sense SNP’s
Variants of Non-synonymous SNP’s. Mis-sense requires a different amino acid after substitution of original nucleotide, while non-sense requires a Stop codon.
97
How does Nonsense SNP’s work?
The more upstream a SNP occurs in DNA sequence, the earlier the stop codon will be specified in protein synthesis - result protein is shorter and maybe not functional.
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Advantages of SNP’s
Create proteins with enhance functions for better survival/tolerance against selective pressures.
99
What are STR’s
Short Tandem Repeats - DNA sequences on a loop (TATATATATA)
100
What does DNA technology do?
It sequences, analysis’s and cutting and pasting of DNA
101
Conservation Genetics
Concerned with population genetic variation and future evolution of species.
102
Population genetics
Link to human evolution such as the Out-of-Africa hypothesis and the multi-regional hypothesis.
103
DNA Profiling plus an example
Involves identifying the genotype of an individual.
DNA fingerprint tests are an example, genetic markers of individuals are analysed to identify relations/identity from the nucleotide sequence in certain regions.
104
DNA Sequencing
Lab technique to determine the exact sequence of nucleotides or bases in a DNA molecule.
105
What is PCR
Polymerase Chain Reaction: Lab technique to rapidly produce/amplify copy’s of specific DNA segments.
106
Ex-Situ and example
Away from its natural location - Outside or off site.
Such as biological material in a lab, collection, botanical garden or zoo.
107
What is an FST value?
Proportion of total genetic variance in a sub population - value from 0-1.
High FST implies great differentiation in a population.
108
What is AFLP
Amplified fragment length polymorphism: PCR based technique to selectively amplify a subset of DNA fragments to generate then compare fingerprints for genomes of interest.
109
What is Sanger Sequencing?
Chain Termination method: Determines nucleotide sequences of DNA.
110
Why are cells referred to as somatic and non-somatic
To differentiate organisms that produce asexually (somatic) and sexually (non-somatic/germ cells)
111
What is a bacteria that use binary fission?
E. Coli
112
What is Parthenogenesis, who uses it?
It’s the process of an unfertilised egg developing into a functional offspring asexually. Done by bees from meiosis, naturally goes from haploid to diploid.
113
Do fungi need male and female to reproduce?
Yes, they must be male and female respectively for mycelium to connect.
114
What is the Dikayophase
Dikaryon is the interphase between plasogamy and karyogamy.
115
What are sporeangiospores
The ends of microscope hyphae that hold the spores for reproduction on the sporangion.
116
What are Cornidia
Holds the genes at the tip of the hyphae (reproduce a/sexual)
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What’s the difference between reproduction methods for fungi?
Both production methods can use the sporangiospores, cornidia, mycelium etc, only difference is that asexual creates a clone, sexual needs male and female to create variant offspring.
