heredity - reproduction Flashcards

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1
Q

How does reproduction ensure the continuity of a species?

A

without reproduction, new individuals are not produced → species will go extinct

in stable environments, asexual reproduction is advantageous → large numbers of offspring + minimal energy used

sexual reproduction → variation → increases the likelihood of a species surviving environmental changes (favourable traits)

agricultural practices → potential to negatively influence the genetic of a species

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2
Q

advantages of external fertilisation

A

little energy required

large number of offspring

offspring spread more widely → less competition

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3
Q

disadvantages of external fertilisation

A

gametes go unfertilised

offspring less protected

offspring die from environment

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4
Q

advantages of internal fertilisation

A

more likely to occur

embryo protected from predators

more likely to survive

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5
Q

disadvantages of internal fertilisation

A

high energy

less offspring

more energy to raise offspring

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6
Q

plant fertilisation

A

The process of the male gamete (pollen) uniting with the female gamete (ovum)

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7
Q

pollination

A

Transfer of gametes from one plant to another

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8
Q

pollinating agents

A

wind or animals (bees) - agents that help pollen spread from one plant to another

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9
Q

self pollination

A

Pollination of the one flower by its own pollen. These are less genetically diverse.

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10
Q

cross pollination

A

rely on outside agents for transfer of pollen from one plant to another.

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11
Q

asexual advantages and disadvantages

A

efficient/fast

short time required to reproduce

no variation → increase risk of disease

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12
Q

hyphae

A

tiny thread of cytoplasm surrounded by a plasma membrane → covered by a wall of chitin

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13
Q

mycelium

A

feeding structure of a fungus → below ground

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14
Q

HOMOthallic

A

self-fertile → ability of a single spore to produce sexually reproducing colony

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15
Q

HETEROthallic

A

Requires haploid cells to fuse in order to produce new individuals.

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16
Q

binary fission

A

cell elongates → genome replicates (any plasmids replicate) → DNA separates to either side → cleavage furrow → two identical daughter cells

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17
Q

conjugation

A

direct transfer of DNA from one bacterial cell to another → introduce genetic variation

18
Q

transformation

A

when naked DNA is taken up from the environment by bacterial cells

19
Q

transduction

A

the use of bacteriophage (bacterial virus) to transfer DNA between cells

20
Q

types of sexual reproduction in protists

A

syngamy → complete fusion of gametes → diploid zygotes

conjugation → temporary union to exchange haploid → forms zygote nucleus → each individual produces daughter cells by binary fission

21
Q

zygote

A

diploid cell resulting from the fusion of gametes

22
Q

blastocyst

A

cell differentiation of cells has occurred. Inner cell mass (ICM) will form the embryo.
The outer layer (called trophoblast) will form the placenta

23
Q

implantation

A

the attachment of the blastocyst to the wall of the uterus

24
Q

morula

A

early stage of cell division - no differentiation

25
Q

process of animal fertilisation

A
  1. sperm makes contact with egg → burrows through corona radiata
  2. sperm attaches to receptor of zona pellucida
  3. digestive enzymes released from acrosome, sperm burrows through zona pellucida
  4. plasma membranes of sperm and egg fuse
  5. sperm nucleus enters egg
26
Q

Follicle stimulating hormone

A

Causes the release of an egg from an ova into the fallopian tube.

27
Q

Luteinising Hormone

A

Develops the ovum and causes ovulation and stimulates production of estrogen and progesterone

28
Q

Estrogen

A

promotes the menstrual cycle but decreases after ovulation

29
Q

Progesterone

A

prepares the uterus for implantation and maintains the uterus during pregnancy.

Prevents the release of further eggs

Decrease in levels of progesterone occur if fertilisation does not occur causing breakdown of the uterus wall.

30
Q

androgen

A

Hormones involved in male sex organs and the production of male gametes.

31
Q

estriol (weak estrogen)

A

inhibit further product of progesterone - preventing uterine contractions

increasing smooth muscle cells of the uterus

32
Q

role in birth oxytocin (love hormone)

A

stimulates the uterine muscles to contract the birthing process

releases milk during breastfeeding

33
Q

prolactin

A

mothering hormone

peaks at labour

central to milk production

34
Q

artificial pollination advantages and disadvantages

A

create plants with desirable traits

breed new variety of plants

cannot guarantee favourable trait is passed on

reduced genetic variation

35
Q

artificial insemination advantages and disadvantages

A

large number of females inseminated

semen is easier to transport than a whole animal

cannot guarantee favourable trait is passed on

reduced genetic variation

36
Q

selective breeding

A

The intentional mating of individuals with desirable traits, in the hope that offspring will express those same traits in their phenotype.

37
Q

cloning

A

genetically identical copies of an organism are made without using the process of sexual reproduction.

38
Q

cloning advantages and disadvantages

A

cloned plants have identical requirements to grow

guaranteed to express desired trait

identical offspring → disease susceptibility

expensive with limited advantages

ethical worries → cloning of humans

39
Q

transgenesis

A

process by which a gene is removed from one species and inserted into the genome of another species.

40
Q

transgenesis advantages

A

guaranteed to express desired traits

increased yield and nutritional value

reduced chemicals needed

41
Q

transgenesis disadvantages

A

identical offspring

espace of GMO population into wild

trade issues with anti-GMO countries

long term effect on health unknown