Biology Chapter 8: Reproduction and Development Flashcards
Multipotency
describes progenitor cells which have the gene activation potential to differentiate into multiple, but limited cell types. For example, a multipotent blood stem cell is a hematopoietic cell, and this cell type can differentiate itself into several types of blood cells, such as lymphocytes, monocytes, and neutrophils, but cannot differentiate into cells of other lineages.
pluripotent
stem cell can give rise to cells of any of the three germ layers: endoderm (tissue lining the gastrointestinal and respiratory linings), mesoderm (muscle, bone, blood, and the lining of most of the urogenital system), or ectoderm (epidermal and nervous tissues).
Totipotency
is the ability of a single cell to divide and produce all of the differentiated cells in an organism (e.g., a zygote is a totipotent cell)
Meiosis I results in _____ haploid cells with _______ chromosomes, each chromosome consisting of _______ sister chromatids.
2 haploid cells with 23 chromosomes, each chromosome consisting of 2 sister chromatids.
Inheritance if something is transmitted through the germ cells,
it means it is heritable and passed on to offspring.
Difference in end result is a non disjunct event occurs in meiosis I or meiosis II
Meiosis I - get 2 trisomy
Meiosis II - get 1 trisomy
ecotderm developmental path (outer layer)
-Outer surface (like skin)
-CNS
-Neural crest
Mesoderm developmental path
Notochord, bone tissue, tubule cells of kidneys, RBC, facial muscles
so mainly musculature, connective tissue (blood, bone and cartilage), gonads, kidneys and adrenals
Endoderm development path
interior lining of body such as gastrointestinal system, pancreas, part of the liver, bladder and lungs
Describe the process of neurulation
What is neurulation
process in which the nervous system is formed
What part in neurulation forms the CNS?
The neural tube
The anterior (rostral) part of the neural tube develops into the brain.
The posterior (caudal) part of the neural tube develops into the spinal cord.
Hormone responsible for triggering ovulation
LH
What is estrogen’s role in the follicular phase?
rises in the follicular phase, stimulates endometrial growth, and triggers the LH surge for ovulation.
What is estrogen’s role in the luteal phase?
Estrogen supports the luteal phase but is secondary to progesterone.
What causes mentruation?
A drop in estrogen leads to menstruation if pregnancy does not occur.
What is Progesterone’s role in the follicular phase?
low Progesterone
What is Progesterone’s role in the luteal phase?
After ovulation, the ruptured follicle transforms into the corpus luteum, which secretes high levels of progesterone.
Key function:
Thickens and maintains the endometrial lining, making it receptive to a fertilized egg.
Inhibits uterine contractions to prevent premature shedding of the lining.
Suppresses FSH and LH to prevent another ovulation in the same cycle.
FSH role in the follicular phase
Early Follicular Phase (Days 1-7) → Stimulates Follicle Growth
FSH is released from the anterior pituitary gland in response to low estrogen and progesterone levels at the start of the cycle.
It stimulates several follicles in the ovaries to grow and mature.
Each follicle contains an immature egg (oocyte) surrounded by granulosa cells that begin producing estrogen.
Difference in function for sperm development testes vs epididymis
The testes are responsible for sperm production (spermatogenesis)
The epididymis functions to mature, store, and transport sperm
Sperm gain motility and the ability to fertilize an egg while passing through the epididymis.
Sperm ejaculation pathway
SEVEn UP
S – Seminiferous tubules (site of sperm production in the testes)
E – Epididymis (sperm maturation and storage)
V – Vas deferens (sperm transport)
E – Ejaculatory duct (merges with the seminal vesicle, transporting sperm)
N – Nothing (just a placeholder in the mnemonic)
U – Urethra (sperm passes through here before ejaculation)
P – Penis (final exit point for sperm)
Describe dev of a sperm
Describe dev of a secondary oocyte
When does meiosis 2 take place in oogenesis
completed only if fertilized
Corona radiata vs zona pellucida
zona pellucida is the glycoprotein layer surrounding the oocyte, essential for sperm binding and preventing polyspermy, while the corona radiata is the outer layer of granulosa cells that provides nutrients and support to the oocyte
A primary oocyte is housed within a
primary follicle
During ovulation, The mature follicle (Graafian follicle) ruptures, releasing
the secondary oocyte (not a fully mature ovum yet)
when does the secondary oocyte become an ovum?
The secondary oocyte becomes an ovum only if fertilization occurs.
Ovum vs zygote
An ovum is a haploid female gamete awaiting fertilization, while a zygote is the diploid cell formed after fertilization, marking the beginning of embryonic development.
Sertoli cells vs leydig cells
Sertoli cells 🏗: Support spermatogenesis inside the tubules.
Leydig cells 🔥: Produce testosterone in the interstitial space.
Cowper’s gland/bulbourethral gland function, location
Function: Secrete pre-ejaculate fluid which lubricates the urethra and neutralizes any remaining acidic urine before ejaculation
Location: Situated near the urethra, below the prostate gland.
Prostate gland function
producing fluid for semen, supporting the urethra, and contracting during ejaculation
Embryo vs zygote
A zygote is a single-cell fertilized egg that forms immediately after sperm and egg fusion, while an embryo is a multicellular developing organism that forms after the zygote undergoes cell division and differentiation.
From which germ layer(s) do the tissues of the heart and blood vessels differentiate?
Mesoderm
trophoblast
trophoblast is the outer layer of the blastocyst.
What germ layer does the CNS and PNS form from?
CNS (Brain & Spinal Cord) → Neural Tube (Ectoderm)
PNS (Peripheral Nerves, Sensory & Autonomic Ganglia, Schwann Cells) → Neural Crest Cells (Ectoderm)
In human females, mitotic divisions of oogonia that lead to formation of presumptive egg cells (primary oocytes) occur between:
Fertilization and birth only
Spermatid vs spermatozoa
Spermatids are immature, haploid cells resulting from meiosis, while spermatozoa are the mature, motile, functional sperm cells that result from spermatids undergoing spermiogenesis (a maturation process).
Difference between endocrine and exocrine
Exocrine glands secrete their products through ducts; endocrine glands release their products into the bloodstream
Women over 35 years of age have an increased risk of nondisjunction due to errors in what phase of meiosis?
Anaphase II
