Reproduction/hormones/Inheritance Flashcards
What is the role of oestrogen
Stimulates the thickening of uterus lining
stimulates the production of LH
What is the function of progesterone
Maintains the uterus lining inhibits (stops) FSH and LH
where is oestrogen produced in the body
Ovaries
What is the role of FSH in the menstrual cycle
stimulates development of the folicle
egg development
surged ovulation
Where is progesterone produced in the body
Ovaries
What is the role of LH in the menstrual cycle
Surges to stimulate ovulation
where is LH and FSH produced in the body
Pituiarty gland
What does FSH stand for
Follicle stimulating hormone
what does LH stand for
Luteinizing Hormone
What is the order of the hormones on the graph
Oestrogen
LH
FSH
Progesterone
What is the role of the placenta in nutrition of the developing embryo
glucose and oxygen diffuse across to allow respiration to occur
what is the job of the amniotic fluid
protects foetus from jolts and bumps
keeps temperature fairly constant
high heat capacity so requires lots of energy to move the temperature either way
what is asexual reproduction
- mitosis
- involves only one parent
- the offspring have identical genes
- no genetic variation
explain mitosis
- growth and repair
- one cell division
- 2 daughter cells
- Diploid
- Occurs everywhere but the sex organs
- no genetic variation
how does mitosis occur
- is when a cell reproduces itself by splitting
- to form two cells with identical sets of chromosomes
-
what is sexual reproduction
Meiosis
- genetic information from two organisms (a father and Mother)
- produces genetically different cells
genetic variation - produces gametes (sperm and egg cells)
what are gametes
Sex cells (egg and sperm)
how many chromosomes does each gamete have
23 chromosomes
haploid
what does sexual reproduction involve
fusion of the male and female gametes
because there are two parents the offspring contain a mixture of their parents genes
what is meiosis features
- produces gametes
- 2 cell divisions
- 4 daughter cells
- haploid
-genetically different - occurs in sex organs
what is an alleles
different versions of the same gene
what is Heterozygous
a trait which you have two different alleles
eg (Dd)
what is homozygous
a trait which you have two alleles are the same
e.g ( AA) or (aa)
what is genotype
the combination of the two alleles that an individual has
letters
What is Phenotype
observable characteristics - the characteristics of the allele produced)
e.g ( brown eyes, female, male,
blue eyes, ginger hair)
words
what is the dominant and recessive allele
dominant- allele is always expressed in the phenotype
Recessive- allele is only expressed in the phenotype when they have 2 copies
what causes discontinuous variation
genetic variation
What causes continuous variation
Features often vary because of a combination of genetic and environmental causes
what is phenotypic variation
Is the variability in the phenotype that exists in a population because of genetic variation and environmental factors
describe the structure/features of insect pollinated flowers
stamen- enclosed within the flower
stigma- Enclosed within the flower ( so insect must make contact)
type of stigma- Sticky so pollen grains attach to insect
Size of petals- big to attract insect
colour of petals - bright to attract insect
Nectary- sweet to attract insects
Pollen grains- large, sticky, hooks
describe the structure/features of Wind pollinated flowers
Stamen - exposed to win
Stigma- exposed to catch pollen blowing in the wind
Type of stigma- feathery to capture pollen
Size of petals- small
Colour of petals- dull no need to attract insects ( usually green)
Nectary- none
Pollen grains, smaller smooth, inflated grains to carry in the wind
what are two ways Plants reproduce asexually
Runners
cuttings
what are the steps for cloning
- artificial method
- cutting
- Gardeners can take cuttings from good plants and then plant them to produce genetically identical copies
- These plants can be produced quickly and cheaply
what are the steps to Runners
strawbwerries
- the parent strawberry plant send out runners - fast growing stems that grow out sideways, just above the ground
- runners take root at various points ( as short distance away) a new plant grows
- The new plants are clones of the plant
( genetically identical)
What is the definition of Haploid
cell only contains one of each chromosome(23)
What is the definition of Diploid
Cell contains two of each chromosome (46)
