Sexual Reproduction Flashcards
Gametes and Zygote difference
Gametes Are HAPLOID HALF THE CHROMOSOME NUMBER
Zygote are diploid normal number of chromosomes
Describe it
Reproduction by two parents
Offspring are genetically different
Relies on MEIOSIS to create sex cells (gametes)
Meiosis
Separates homologous chromosomes then chromatids
Happens in the gonads
Produces haploid cells
Introduces greater variation and diversity to population
Prophase I
Homologous chromosomes are next to each other
Prophase I
Homologous chromosomes are next to each other
Metaphase I
Homologous chromosomes are lined up ward
Anaphase I
Homologous chromosomes separate
Telephase I
Each daughter cells has two chromosomes
Male gonads
Testes, produces sperm
Need to be in scrotum to keep temperature around 35.5
Sperm
Produced by meiosis
Haploid
Stored in dpidydymus
Lutenising hormone in males
Causes testes to produce larger amount of testosterone
Pathway of sperm
Epididymis - Vas Deferens - urethra (fluids are added) which forms semen
How many eggs are produced in females
1, there are not four cells produced because only one haploid egg gets most of the nutrients
Female gonads are…
Ovaries
Where does fertilization happen
Fallopian tubes
What helps move the eggs
Cilia in the tubes
How do eggs mature
In a follicle.
Lutenising hormone causes the follicle to get bigger and causes the egg to be released.
What is the folicle called when egg is release
Corpus luteum
What is produced as the follicle gets bigger
Oestrogen is produced. Gets the uterus ready for pregnancy and causes uterus lining to get thicker
What does the corpus luteum produce
Progesterone - which maintains uterus lining
If woman does not get preg, the copus gets smaller and levels of progesterone decreases. And the uterus lining is lost
Gamete of plants
Pollen (male) egg female egg)
Wind pollinated flowers
Pollen are small and dry
Large amounts are produced
Flowers are small
Disadvantages of wind pollination
Cannot control direction of it
Relies only on luck
Animal pollination
Flowers and petals brightly colored
Strong scent
Nectar may be secreted
Stigmas are taller than stamens to prevent self pollination
