Mod 5: Question 1 Flashcards
Sex is…
expensive: uses lots of time and energy
may result in fighting
can be dangerous
Vocab: Maternal
relating to a mother; especially during pregnancy or shortly after childbirth
Vocab: Paternal
related to the father
Vocab: Zygote
fertilised egg
Vocab: Gametes
a mature haploid male or female germ cell which is able to unite with opposite sex
Vocab: Meiosis
cell division, 4 daughter cells each with half chromosomes of parent cell
Vocab: Somatic cells
any cell of a living organism other than the reproductive cells
Vocab: N
number of chromosomes in a gametes (23)
Vocab: 2N
number of chromosomes in somatic cells (46)
Vocab: X and Y chromosomes
sex chromosomes;
female = XX
male = XY
Vocab: Unisexual
either male or female - representing 1 sex
eg. humans
Vocab: Hermaphrodites
an animal containing both male and female sex organs
eg. snail
Vocab: Fertilization
action/process of fertilizing an egg or a female plant; involving fusion of male and female gametes to form a zygote
Vocab: Implantation
pregnancy - blastocyst attaches to the uterine wall of the endometrium lining
Vocab: Placental mammal
- hair or fur
- internal fertilization
- give birth to live young
- feed growing fetus via placenta and umbilical cord
- produce milk through mammalian glands
Vocab: Hormone control
1) positive feedback - rare (birth)
the increase will continue to increase eg. contractions, breastfeeding
2) negative feedback - most common
one goes up another goes down to bring it back to normal eg. when your hot body cools you down
Vocab: Changing hormones
1) hormones to make gametes and courtship
2) hormones for setting up uterus for pregnancy
3) hormones to hold the pregnacny
4) hormones for birth
Asexual Reproduction
- one parent
- identical genetics
- diviosn through - mistosis, binary fission, budding, vegetative propogation
advantages: high effciency (less time and energy) - population increase
disadvantages: low genetic variation - less lkely to survive change
organisms - plants, fungi, bacteria, protists
eg. Yeast (spores)
Sexual Reproduction
- two parents
- unique genetics
- division through - meiosis
advantages: high genetic variation - population is likely to survive change
disadvantages: low efficency (time and money) - slow reproductive rate
organisms - animals, plant, fungi
eg. Humans
External Ferterlisation
occurs outside of the animals body
* needs an aquatic enviroment (so they don’t dry out)
* gametes release at same time (evolved to have syncronised cycles with specific mating patterns)
* both sex’s produce hundreds of gametes (most die before birth due to low protection by parent)
* low chance of fertilisation due to being released in the open
produce jelly eggs
eg. cane toads, salmon
Internal Fertilisation
fertalisation occurs inside the body
* occurs in reproductive tract of the female (high success rate due to enclosed/suited enviroment)
* don’t breed as frequenctly (greater energy expenditure)
* produces fewer gametes (enough to allow continuity of species)
eg. seagull, cobra snake
Internal vs External Fertilisation
Similarities
- both sperm and egg gametes
- need a watery enviroment (favourable conditions for fertilisation)
- parental investment is indirectly proportional to number of zygotes produced
Vegatative Propagation
asexual plant reproduction
three
Runners
* long thin shoots - grow on surface of soil
* tip of node turns up and thicknes - creates new roots and shoots
* A and D: less energy, fast, competition for light
eg. strawberry
Rhizomes
* underground runners - give rise to new shoots at each node
eg. ginger, fern
Artificial Grafting
* plant leaves are inseted into the root system of another tree
* buds will begin to shoot
new individual plants arise from the stem, roots or leaves as a clone
Sexual Reproduction - plants
anther (male part - makes pollen) matures first so there isn’t any self pollination with the stigma (female part - attracts pollen, sticky)
Stages:
1. pollination
2. fertilisation
3. seed dispersal
4. germination
ferns, mosses, gymnosperms (cb), angiosperms (fb)
male part - carpel
female part - pistil
Pollination - plants
sexual reproduction
Step 1
pollen sticks to the stigma which is sticky when ready for fertilisation
flowers attract animals to bring the pollen
methods:
* wind - flowers with small petals, no nectar or colour, pollen is light and powdery eg. grass
* self - male will produce pollen (anther) and fertalise itself (less energy) eg. dandilions
* insects - yelllow or blue flowers, with necar and scent eg. bees
* birds - large, colourful, tuba shape (for beak), lots of nectar, no smell eg. lorakeets
Flower anatomy
EDIT
TO COME SOON
Fertilisation - plants
sexual reproduction
Step 2
- sperm cells transfered by the pollen tube
- fuses with the egg in the ovule
- fertlised ovule develps in the ovary
- ovule, containg embryo, is now a seed and the surronding ovary becomes a fruit
seed is a zygote
only in seeding plants - gymnosperms and angiosperms
Seed dispersal - plants
sexual reproduction
Step 3
after fertilisation the seeds are dispered
it is an advatafe for seeds to be dispered as:
* prevents overcrowding
* prevents compitetion - light, water and soil nutrients
* increases chance of continuity in case of change
Travel by:
air (dandelion), animal (blackberry), water (coconut), bursting (violet), human (cherry)
Germination - plants
sexual reproduction
Step 4
plant embryo is in a dehydrated form and is dormant - seed needs adverse conditions to survivie (water, nutrients, warmth)
embryo begins to grow creating a radicle to absrob nutrients and a plume for food production via photosythesis
once seed is established it grows into an adult plant and can reproduce
Budding - fungi
Asexual repoduction
- needs a conjusive enviroment
- parent is not effected
nucleus reproduces through mitosis and a little bud forms off the side; once nuclus moves into - pinches off to become its own organism or stays attatched in a colony
Spores - fungi
Asexual reproduction
Special unicellular fungi produced in huge quantities from one parent - very light to they can send offspring far away (good distribution)
* spores last a long time and won’t become fungi until conditions are right - survival of species
* most are haploid
Sexual reproduction - fungi
- occurs only when enviroment isn’t conjusive - goes into stasis
- diplod and haploid phase - mainly haploid
two different indiduals fuse to from a zygote spore
goes through meioso to form haploid spores which are genetically different from parent
Binary fission - protists
Asexual Reproduction
- Organism grows to double its size (doesn’t want to be small)
- Nucleus goest through mitosis to replicate genetic material - splits into two identical cells (mature size)
most common way to mate
eg. amoeba
Budding - protists
Asexual reproduction
nucleus goes through mitosis, a bud is formed and pinches off without changing the parent
Binary fission - bacteria
Asexual reproduction
- DNA replicates and one piece goes to either side of the cell
- clevage occurs and cytoplasm divides
- creates a smaller daughter cell which grows and matures
occurs in 9 minutes (rapid increase in numbers)
Bacteria Conjugation
Sexual reproduction
have hundreds of plasmids
two cells send a ‘tube’ where they replicate plasmids and send to the other cell
Artificial pollination
Plants
Stamen is manually removed from female part and pollen is transferred to the sticky stigma
* D - takes time/requires skill
* A - allows pollination to happen anywhere in the world
self or cross pollinated (choosing hybrid plants with different traits)
Cloning
Plants
Vegetative Propogation eg. strawberroes/bananas
* D - no variation (dieases can wipe out whole species)
* A - produced exact quality crops as parent/if no viable seeds plant can still reproduce
Selective breeding/artifical selection
Plants
eg. wild brassica - cauliflower, kale, cabbage, brussel sprouts, broccoli
* D - reduces genetic variation
* A - produces new varities of plant (agriculture demands)
Selective breeding
Animals
Intentional mating of individuals with desirable traits so there offspring express those same traits eg. chickens
* D - reduces genetic variation/sometimes rare disease genes can be passed on
* A - produces new variaties of animals (agriculture demand/high quality food)/animals can be selected that dont cause harm - cattle without horns
Artifical Insemenation
Animals
