Plants + Animals Flashcards
What is Asexual reproduction
Is a process that results in the production of genetically identical offspring (clones) from one parent
Does not require gametes
Strawberry plants, spider plants
What is sexual reproduction
Requires gametes
Fusion of male + female gametes to form a zygote
Lots of genetic variation
What is Mitosis used in
Asexual reproduction
2 daughter cells
What is Meiosis used in
Sexual reproduction
4 daughter cells
Give the differences between Mitosis and Meiosis
Mitosis occurs in asexual reproduction and the 2 daughter cells are genetically identical to parent cell with only one cell division.
Meiosis = sexual reproduction, 2 cell divisions and the gametes have half the genetic material of the parent cell.
What is a Haploid cell
Half number of chromosomes in nucleus (23)
What is a Diploid cell
Complete cell (46 chromosomes)
What is the function of the fallopian tube
Takes the egg from the ovary to uterus
What is the ovary
Where the eggs are produced
What id the crevix
Holds grown=ing fetes in place
What do the glands do in males
Secrete a liquid to add to sperm, combined called semen
What is the sperm duct
Tube that allows sperm to travel from testes to penis
Give some ways in which the sperm cell has adapted
Flagellum to swim
Receptors o head to detect chemicals secreted by egg
Streamlined
Packed with mitochondria
How has the egg cell developed
Zona pelliccia hardens during fertilisation, prevents poly sperming
Big cell, contains nutrients for the zygote as it undergoes cell division
Explain the journey of the sperm
The sperm is made in the testes by Meiosis, the then travels up the sperm duct to uretha where it is joined by liquids to form semen. This will the be released into the vagina and by using its flagellum it is able to swim towards the crevix.
Define fertilisation
The fusion of male + female gametes
What is a zygote
The first fertilised egg
Give the journey of the egg (6 stages)
The unfertilised egg travels doen fallopian tube
Egg is fertilised by sperm
The zygote undergoes cell division (Mitosis) to form an embryo
The embryo implants into the thickened uterus wall, a placenta develops
The embryo continues to grow, the amniotic fluid acts to protect it
The fully developed foetus is ready to be born
What is the function of the placenta
Attachment that develops from fetes to mothers uterus, allows embryo to extract nutrients from blood
How has the placenta adapted
Villi, large surface area
High concentration gradient
Villi have thin walls
What travels into the umbilical cord
Oxygen
Glucose
Amino acids
Vitamens
What travels out of the umbilical cord
Carbon dioxide
Urea
What does Oestrogen do
Made in Ovaries
Development of secondary characteristics (breast growth, menstruation)
Repairs Uterus lining
What is Progesterone
Made in Ovaries
Regulates menstrual cycle
Maintains lining of Uterus
What is Testosterone
Made in Testes
Development of secondary male characteristics
What is FSH
Made in Pitduraly gland
Stimulates spem production in Men
Maturation of egg cells in women
What is LH
Stimulates Ovulation
Define Puberty
A time period in which bodily changes occur yo make individual reproductivity ready
What happens on Day 1
Uterus lining breaks down, menstruation occurs
Low levels of Oestrogen and Progesterone
Ash stimulating development of egg
What happens on Day 7
Uterus lining thickens again, stimulated by Oestrogen
What happens on Day 14
Ovulation ocurres
Stimulated by LH
What happens on Day 21
Uterus lining is maintained by high levels of progesterone
What is Menstruation
The breaking down of the uterus lining
What is the menstrual cycle
The continuous sequence of events in the woman’s reproductive system
What is the function of the Anther
Produces the male gametes
What is the Style
Positions Stigma to accept pollen grains. Pollen tube will grow through the style
Define pollination
The transfer of pollen from the anther to the stigma of plant
Give the difference for the stigma in wind and insert pollinated plants
Insect - Found within the flower, insect brush it as they enter, often sticky
Wind - Extend out of flower, feathery to catch pollen, large
What is the stigma
Where the pollen grins attach to
Give the difference win pollen in wind and insect pollinated plants
Insect =
- Large + stick to attach
- Small quantities
- Heavy
- Some have spikes
Wind =
- Lighter to be carried by wind
What does the pollen tube allow
The nucleus to travel from the pollen grin to the ovary
How does the pollen tube grow dow through the style
Pollon grain secretes enzymes that clear a path to the ovary
What does the ovary become after fertilisation
A fruit
What does the Ovule become after fertilisation
A seed
Give 3 factors required for germination
Moisture
Warmth
Oxygen
