D3.1 Reproduction

What is the process by which living organisms generate more members of their own species? Reproduction

What are the two types of reproduction? Sexual and asexual reproduction

What is the main effect of sexual reproduction? Brings about change

What is the main effect of asexual reproduction? Brings about continuity

What are the two key processes in the sexual life cycle of eukaryotes? Meiosis and fusion of gametes

What is fertilization? The fusion of a male and female gamete

What does fertilization result in? Formation of a new individual

Why does fertilization double the chromosome number? Because it combines chromosomes from both parents

What process prevents chromosome doubling every generation? Meiosis

What is the chromosome number of gametes? Haploid

What is the chromosome number of body cells? Diploid

At what stage does meiosis happen in animals? During the process of creating gametes

What is the evolutionary significance of meiosis? It was a critical step in the origin of eukaryotes

What is isogamy? Fusion of outwardly identical gametes

What is anisogamy? Fusion of different male and female gametes

What do the testes produce? Sperm and testosterone

What is the function of the scrotum? Holds testes at a lower than core body temperature

Where are sperm stored until ejaculation? Epididymis

What is the function of the sperm duct? Transfers sperm during ejaculation

What do the seminal vesicle and prostate gland secrete? Fluid containing alkali, proteins, and fructose

What is the function of the urethra in males? Transfers semen during ejaculation and urine during urination

What is the function of the penis? Penetrates the vagina for ejaculation of semen near the cervix

What do the ovaries produce? Eggs, oestradiol, and progesterone

What is the function of the oviduct? Collects eggs, provides a site for fertilization, and moves the embryo to the uterus

What is the function of the uterus? Provides for the needs of the embryo and fetus during pregnancy

What does the cervix do during pregnancy? Protects the fetus and dilates to provide a birth canal

What is the function of the vagina? Stimulates the penis and provides a birth canal

What does the vulva protect? Internal parts of the female reproductive system

What is the menstrual cycle? A cycle of changes in the uterus and ovary regulated by hormones

What are the two parts of the menstrual cycle? Uterine cycle and ovarian cycle

What is the first half of the ovarian cycle called? Follicular phase

What occurs during the follicular phase? Follicles develop, and the most developed follicle releases an egg

What is the release of an egg called? Ovulation

What is the second half of the ovarian cycle called? Luteal phase

What is the corpus luteum? The structure formed from the follicle wall after ovulation

What happens to the corpus luteum if fertilization does not occur? It breaks down

What is the uterine cycle? Changes in the endometrium during the menstrual cycle

What happens to the endometrium during the luteal phase? It thickens in preparation for implantation of an embryo

What occurs if there is no embryo? The endometrium breaks down and is shed during menstruation

What event marks Day 1 of the menstrual cycle? The start of a woman’s period

What happens after menstruation ends? The lining of the uterus is repaired and thickens

What regulates the menstrual cycle? Four hormones: FSH, LH, oestradiol, and progesterone

What is the function of FSH? Stimulates follicle development and secretion of oestradiol

What is the function of oestradiol? Stimulates repair of the endometrium and inhibits FSH secretion

What triggers ovulation? A sharp peak in LH

What is the function of progesterone? Promotes thickening of the endometrium and inhibits FSH and LH

What is fertilization? The fusion of a sperm with an egg to form a zygote

What prevents entry of multiple sperm into the egg? The glycoprotein layer hardens after fertilization

What happens to sperm mitochondria after fertilization? They are destroyed

What is in vivo fertilization? Fertilization inside the body

What is in vitro fertilization (IVF)? Fertilization outside the body in controlled laboratory conditions

What is the first step in IVF? Downregulation

What hormone is injected during IVF to stimulate follicle development? FSH

What hormone matures follicles in IVF? Human chorionic gonadotropin (hCG)

How are eggs collected in IVF? By using a micropipette mounted on an ultrasound scanner

Where do meiosis and fertilization occur in flowering plants? Inside flowers

What are the male parts of a flower called? Stamens

What are the female parts of a flower called? Carpels

What is pollination? Transfer of pollen from an anther to a stigma

What carries male gametes to the ovule in flowering plants? Pollen tube

What does a zygote develop into in flowering plants? An embryo

What is cross-pollination? Transfer of pollen from one plant to another

Why is cross-pollination important? Promotes genetic variation and hybrid vigor

What is self-pollination? Transfer of pollen from an anther to a stigma on the same plant

What is inbreeding depression? Failure to thrive and infertility due to inbreeding

What is self-incompatibility? A mechanism preventing self-pollination in plants

Why might a single variety in an orchard produce little fruit? Lack of genetic diversity and self-incompatibility

What is the function of nectaries in flowers? Secrete nectar to attract pollinators

What is the role of petals in insect-pollinated flowers? Attract insects and guide them to anther or stigma

What is the role of scent in flowers? Advertises the flower to pollinators

What are the advantages of cross-pollination over self-pollination? Genetic variation and resistance to environmental change

What ensures that only one sperm fertilizes an egg? Hardening of the egg’s glycoprotein layer

What happens to chromosomes after fertilization? They combine during the zygote’s first mitosis

What is the outcome of successful pollination and fertilization in plants? Formation of seeds and embryos

What is reproduction?

A process by which living organisms generate more members of their own species.

What are the two types of reproduction?

Sexual and asexual reproduction.

How does sexual reproduction differ from asexual reproduction?

Sexual reproduction brings about change, while asexual reproduction brings about continuity.

What two processes must a sexual life cycle include?

Meiosis and fusion of gametes.

What is fertilization?

The fusion of a male and female gamete to form a new individual.

What happens to chromosome numbers during fertilization?

Fertilization doubles the number of chromosomes.

What process halves the chromosome number during the sexual life cycle?

Meiosis.

What are the two types of gametes called in anisogamy?

Male and female gametes.

What does the testis produce?

Sperm and testosterone.

What is the role of the scrotum?

It holds the testes at a temperature lower than the core body temperature.

Where is sperm stored until ejaculation?

In the epididymis.

What is the function of the sperm duct?

It transfers sperm during ejaculation.

What do the seminal vesicle and prostate gland secrete?

Fluid containing alkali, proteins, and fructose, added to sperm to form semen.

What is the role of the ovary in the female reproductive system?

It produces eggs, oestradiol, and progesterone.

What occurs during ovulation?

A mature egg is released from the follicle into the oviduct.

What does the corpus luteum secrete during the luteal phase?

Oestradiol and progesterone.

What is the role of progesterone in the uterine cycle?

It promotes the thickening and maintenance of the endometrium.

What is the significance of cross-pollination in plants?

It promotes genetic variation and hybrid vigor.

What is self-incompatibility in plants?

A mechanism preventing self-pollination by stopping pollen from germinating or growing.

How do fruit farmers benefit from self-incompatibility mechanisms in plants?

By planting different varieties with distinct self-incompatibility alleles to ensure abundant crops.

What is seed dispersal?

Seed dispersal is the movement of seeds away from the parent plant to reduce competition and spread the species.

Why does seed dispersal reduce competition?

It reduces competition between offspring and the parent plant.

What are the types of seed dispersal?

Dry and explosive, fleshy and attractive for animals to eat, feathery or winged to catch the wind, and covered in hooks to catch onto animals.

Is seed dispersal the same as pollination?

No, seed dispersal and pollination are separate processes in the plant's sexual life cycle.

What is puberty?

Puberty is the sequence of developmental changes that lead to sexual maturity.

What controls the onset and progress of puberty?

The brain controls puberty via hormone secretion, particularly through gonadotropin-releasing hormone (GnRH).