Chapter 9: Reproduction and Development

Fill-in-the-blank practice flashcards covering plant reproduction, human spermatogenesis, oogenesis, reproductive endocrinology, fertilization, embryogenesis, and growth patterns.

In flowering plants, the multicellular diploid stage that produces haploid spores is known as the __________ generation.

sporophyte

A diploid cell in the microsporangium that divides by meiosis to give rise to 4 haploid microspores is termed a __________.

microsporocyte

Within a pollen grain, the __________ divides by mitosis to form 2 non-motile sperm.

generative cell

The female gametophyte structure that develops in the ovule containing 8 nuclei formed by mitotic division of the surviving megaspore is the __________.

embryo sac

The three haploid cells in the embryo sac situated at the opposite end to the micropyle are called __________.

antipodal cells

During double fertilization, one sperm unites with the egg while the second sperm fuses with two polar nuclei to form a triploid ($3n$) __________.

endosperm

In the male reproductive system, sperm are produced inside coiled structures in the testes called __________.

seminiferous tubules

The acrosome of a spermatozoon is a specialized vesicle containing hydrolytic enzymes that differentiates from the __________.

Golgi body

The flagellum tail of a spermatozoon features a __________ arrangement of microtubules for motility.

$$9+2$$

Luteinizing hormone (LH) stimulates the __________ scattered between the seminiferous tubules to secrete testosterone.

Leydig cells

Sertoli cells synthesize __________, which binds to testosterone and promotes spermatogenesis.

Androgen Binding Protein

Sertoli cells secrete a peptide hormone called __________ that exerts negative feedback on the anterior pituitary gland to reduce FSH secretion.

inhibin

The continuous process of spermatogenesis in adult human males takes approximately __________ weeks.

$$7$$

The differentiation process in which haploid spermatids transform into mature spermatozoa is called __________.

spermiogenesis

In human females, primary oocytes begin meiosis during embryonic development but remain arrested at __________ until puberty.

prophase I

At ovulation, the released secondary oocyte is arrested at __________ of meiosis II.

metaphase

The secondary oocyte is encased by the __________, a glycoprotein layer that develops a jelly coat.

zona pellucida

The layer of granulosa cells surrounding the zona pellucida that supplies nutrients to the developing oocyte is called the __________.

corona radiata

A steep rise in estrogen near day 14 of the ovarian cycle triggers an __________, leading directly to ovulation.

LH surge

During the luteal phase, the ruptured follicle transforms under LH stimulation into the __________, which secretes progesterone and estrogen.

corpus luteum

During the secretory phase of the uterine cycle, endometrial glands enlarge and secrete fluid rich in __________ to prepare the uterus for embryo implantation.

glycogen

The functional maturation of sperm in the female reproductive tract involving the removal of cholesterol and glycoproteins from the acrosomal cap is called __________.

capacitation

During the acrosomal reaction, the hydrolytic enzymes released to digest a path through the zona pellucida are hyaluronidase and __________.

acrosin

During fertilization, the exocytosis of enzymes by cortical granules alters the zona pellucida to prevent __________.

polyspermy

Repeated cleavage divisions of the zygote produce a solid sphere of 32 cells known as a __________.

morula

A blastocyst is composed of an inner cell mass and an outer epithelial layer known as the __________.

trophoblast

Implantation of the blastocyst into the endometrium is initiated by the trophoblast approximately __________ after fertilization.

1 week

The process by which the inner cell mass differentiates into three embryonic germ layers is known as __________.

gastrulation

The flexible rod formed from the mesoderm layer that develops into the vertebral column discs is the __________.

notochord

During organogenesis, the nervous system, sense organs, and pituitary gland differentiate from the __________ layer.

ectoderm

After implantation, the trophoblast secretes __________ to maintain the corpus luteum and prevent menstruation.

hCG

By the end of the first trimester, the __________ takes over the role of the corpus luteum to secrete progesterone and estrogen.

placenta

During labor, oxytocin stimulates the placenta to make __________, which further induce contractions of the uterus.

prostaglandins

The amplification of uterine contractions driven by oxytocin and prostaglandins during parturition is governed by a __________ feedback mechanism.

positive

The growth of an organ at a different rate compared to the rest of the body is described as __________ growth.

allometric

In human allometric growth, __________ tissue grows rapidly from birth until early adolescence, reaching almost 200% of adult capacity before regressing.

lymphoid

In the limited growth curve of annual plants, the initial drop in dry mass during germination is caused by __________ of stored food reserves.

aerobic respiration

The unlimited growth curve typical of perennial woody trees is comprised of a continuous series of smaller __________ curves.

sigmoid