Asexual and Sexual Reproduction Flashcards
Define asexual reproduction
A process resulting in the production of genetically identical offspring from one parent
What type of cell division (mitosis or meiosis) is used for asexual reproduction?
Mitosis is used for asexual reproduction
What types of organisms can reproduce asexually?
Mainly bacteria, fungo, small plants and animals. Also potatoes, bulbs.
What are the advantages of asexual reproduction?
- faster
- requires less energy
What are the disadvantages of asexual reproduction?
offspring are all genetically identical. reproduction does not produce genetic variation
Describe fertilisation
the fusion of the nuclei of
gametes
Define sexual reproduction
A process involving the fusion of the nuclei of two gametes to form a zygote and producing offspring that are genetically different from one another
What type of cell division is used in sexual reproduction?
Gametes are formed by meiosis, zygote divides by mitosis
What are the male and female gametes in, in animals?
Sperm and egg cell (ovum)
What are the male and female gametes in, in plants?
Pollen and Egg cell
gametes are formed by _________, a type of cell division which produces cells with _______ the chromosome numbers.
meiosis, half
nuclei of gametes are h______ and the nucleus of a zygote is d______.
nuclei of gametes are HAPLOID and the nucleus of a zygote is DIPLOID.
Discuss the advantages and disadvantages of
sexual reproduction:
(a) to a population of a species in the wild
(b) to crop production
Define self-pollination
the transfer of pollen grains from the anther of a flower to the stigma of the same flower or a different flower on the same plant
Define cross-pollination
cross pollination increases genetic variation
Discuss the potential effects of self-pollination
and cross-pollination on a population, in terms of
variation, capacity to respond to changes in the
environment and reliance on pollinators
fertilisation occurs when a p_____ nucleus f____ with a nucleus in an o______.
fertilisation occurs when a POLLEN nucleus FUSES with a nucleus in an OVULE
Describe the structural adaptations of
insect-pollinated and wind-pollinated flowers
Define fertilisation
the fusion of the nuclei from a male gamete (sperm) and a female gamete (egg cell)
Explain the adaptive features of sperm, limited
to: flagellum, mitochondria and enzymes in the
acrosome
What happens to the zygote in early development?
the zygote
forms an embryo which is a ball of cells that
implants into the lining of the uterus
What can pass across the placenta and affect the foetus?
some pathogens and toxins
Describe the roles of testosterone and oestrogen
in the development and regulation of secondary
sexual characteristics during puberty
thumbs up
Describe the menstrual cycle in terms of changes
in the ovaries and in the lining of the uterus
uterus lining will become thicker in preparation for an embryo potentially implanting. if no implantation occurs, the lining is shed during menstruation and the cycle repeats.
Describe the sites of production of oestrogen
and progesterone in the menstrual cycle and in
pregnancy
produced in the ovaries and pituitary glands.
explain the role of FSH
fsh (follicle stimulating hormone)
- stimulates egg manipulation in the follicles of the ovary
- stimulates follicles in the ovaries to secrete oestrogen
Define a sexually transmitted infection
an infection that is transmitted through sexual contact
the human immunodeficiency virus (HIV) is…
a pathogen that causes an STI
HIV infections may lead to ____S.
Describe the methods of transmission of HIV
Explain how the spread of STIs is controlled
Gametes are said to be h_______. This means that they have a single set of chromosomes. In humans this means they have 23 chromosomes
HAPLOID
Parts of a male flower
Stamen and anther
what do stamen consist of?
filament
parts of a female flower
carpel, style, ovary, and ovules
What do carpel consist of?
stigma (sticky opening)
What is a style?
long tube connecting stigma to ovary
What does the ovary do? (relevant to flowers)
houses ovules; becomes fruit
What is the function of ovules?
develop female gametes; become seeds
explain the role of LH
at its peak, stimulates the uterus to develop a lining (to replace the lining lost during menstruation)
results in the formation of a corpus luteum
explain the role of oestrogen
stimulates the uterus to develop a lining (to replace the lining lost during menstruation)
post-ovulation, inhibits FSH and LH production in the pituitary gland
