IB Biology HL D3.1 Reproduction Questions

Practise IB Biology HL D3.1 with evidence-led questions on gamete formation, fertilization, reproductive hormones, pregnancy, development and contraception.

Exam points

Compare asexual clones with sexual reproduction; link meiosis and gamete fusion to ploidy and variation.
Identify human reproductive structures from diagrams and explain their functions.
Interpret ovarian and uterine hormone graphs and explain FSH/LH feedback.
Explain fertilisation from acrosome penetration to nuclear fusion and the cortical block to polyspermy.
Sequence IVF from FSH treatment and egg collection to embryo culture and transfer.
Identify floral structures and infer haploid meiotic products in anthers.
Trace pollen-tube growth to fertilisation and relate insect-flower adaptations to pollen transfer.
Explain how dioecy and self-incompatibility promote cross-pollination and reduce inbreeding.
Link seed dispersal to reduced competition; trace water, gibberellin and amylase in germination.
Trace hypothalamic GnRH through pituitary FSH/LH to sex-hormone production at puberty.
Compare spermatogenesis and oogenesis using meiotic stages, ploidy and cell outputs.
Trace blastocyst formation and implantation; explain HCG tests and corpus-luteum maintenance.
Explain placental exchange and pregnancy hormones; trace oxytocin-prostaglandin feedback in labour.

Covered syllabus points

D3.1.1—Sexual vs. asexual reproduction D3.1.2—Role of meiosis and gamete fusion D3.1.3—Male vs. female sexes D3.1.4—Human reproductive system anatomy D3.1.5—Ovarian and uterine cycles D3.1.6—Fertilization in humans D3.1.7—In vitro fertilization (IVF)D3.1.8—Sexual reproduction in flowering plants D3.1.9—Insect-pollinated flower features D3.1.10—Promoting cross-pollination D3.1.11—Self-incompatibility mechanisms D3.1.12—Seed dispersal and germination D3.1.13 (HL)—Puberty control D3.1.14 (HL)—Gametogenesis D3.1.15 (HL)—Preventing polyspermy D3.1.16 (HL)—Blastocyst and implantation D3.1.17 (HL)—Pregnancy testing D3.1.18 (HL)—Placenta role D3.1.19 (HL)—Hormonal control D3.1.20 (HL)—Hormone replacement therapy (HRT)

[Maximum number: 1]

Which diagram(s) represent(s) processes used in asexual reproduction?

I only

I and II only

II only

I, II and III

[Maximum number: 4]

Members of a species typically all have the same number of chromosomes.

Explain the need for both fusion of gametes and meiosis in a sexual life cycle.

[Maximum number: 18]

(a)

Draw a labelled diagram of the male reproductive system.

[ 4 ]

(b)

Outline the process of in vitro fertilization (IVF).

[ 6 ]

(c)

Explain how the structure and functions of the placenta maintain pregnancy.

[ 8 ]

[Maximum number: 4]

Draw a labelled diagram of the male reproductive system.

[Maximum number: 4]

Hormones are produced in plants and animals and cause changes in the organism.

Outline hormone feedback mechanisms in the menstrual cycle.

[Maximum number: 6]

Describe the process of fertilization in humans.

[Maximum number: 6]

Outline the process of in vitro fertilization (IVF).

[Maximum number: 3]

Angiospermophyta are vascular flowering plants.

The flowers of angiospermophyta are used for sexual reproduction. Outline three processes required for successful reproduction of angiospermophyta.

[Maximum number: 4]

Draw a half-view of an animal-pollinated flower.

[Maximum number: 1]

Flowering plants can use either self-pollination or cross-pollination when they carry out sexual reproduction. Which plants are most likely to cross-pollinate?

Plants that are hermaphrodites

Plants whose anthers and stigmas mature at the same time

Plants with flowers that have much longer stamens than stigmas

Plants that are either male or female

[Maximum number: 5]

Outline the metabolic processes during germination of a starchy seed.

[Maximum number: 1]

What controls the developmental changes during puberty?

I. Increased release of gonadotropin-releasing hormone (GnRH) by the hypothalamus
II. Luteinizing hormone (LH) leading to increased sex hormone production
III. Gonadotropin-releasing hormone (GnRH) triggering the onset of increased luteinizing hormone (LH)

I and II only

I and III only

II and III only

I, II and III

[Maximum number: 8]

Cell biologists play an important role in research into disease, fertility, evolution and many other areas of science.

Compare and contrast the processes of spermatogenesis and oogenesis.

Oogenesis	Spermatogenesis
in the ovaries	in the testes
starts «in germinal epithelium» during embryo/fetus development	starts during puberty/adolescence OR continuously starting «in germinal epithelium»
pauses occur in prophase I/prophase II/metaphase II	no pauses
large quantity of cytoplasm in egg / cytoplasm split unequally	small quantity of cytoplasm per sperm / equal division of cytoplasm
one cell/egg «per meiosis» OR some become polar bodies	four sperm «per meiosis» OR all cells become sperm
one «usually» at a time/per month/per menstrual cycle	many/far more/millions daily
released on about Day 14/in middle of menstrual cycle/at ovulation	released continuously «from testis» OR by ejaculation/intercourse
stops at menopause	goes on throughout adult life/until death

[Maximum number: 2]

Hemophilia is a sex-linked disease that affected some members of royal families in Europe during the 19th and 20th centuries.

Explain the mechanism that prevents polyspermy during fertilization.

[Maximum number: 1]

What is a blastocyst?

An unfertilized egg surrounded by follicle cells

An unfertilized egg cell expelled by menstruation

The follicle when it has swelled up with fluid

The embryo when it has become a hollow ball of cells

[Maximum number: 1]

What is a function of human chorionic gonadotropin (HCG)?

To stimulate the corpus luteum to produce progesterone during early pregnancy

To stimulate contraction of uterine muscles at the onset of birth

To inhibit the production of progesterone and prevent menstruation during pregnancy

To prevent polyspermy during fertilization in the fallopian tubes

[Maximum number: 8]

Explain how the structure and functions of the placenta maintain pregnancy.

[Maximum number: 7]

Feedback mechanisms are used in living organisms both to promote and respond to change.

Describe the hormone feedback mechanisms that help to prepare a woman's body for pregnancy, sustain the pregnancy and then give birth.

All question bank results loaded

a	FSH promotes estrogen secretion (by the follicle) OR FSH promotes follicle development and follicles secrete estrogen;
b	(high levels of) estrogen inhibits FSH secretion (by the pituitary gland);
c	(high levels at ovulation of) estrogen promotes LH secretion (by pituitary gland);
d	LH promotes progesterone secretion (by the corpus luteum) OR LH induces corpus luteum development and the corpus luteum secretes progesterone;
e	(high levels of) progesterone inhibits LH/FSH secretion (by the pituitary gland);
f	progesterone secretion decreases due to reduced LH/FSH (concentration);
g	FSH secretion increases due to reduced progesterone (concentration) OR decrease in progesterone restarts the cycle;

Covered syllabus points

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Question (b)

Question (c)

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