BIOL 200 Exam #4

What are the two types of receptors on a sperm

Jelly coat receptors and resact receptors

What is the jelly coat receptor

a receptor on the sperm that binds with the jelly coat of the oocyte

What is a resact receptor?

a receptor that signaling molecules called resact released by the oocyte bind to this receptor and cause the sperm to swim faster and straighter to the oocyte

What type of receptor is this?

What type of receptor is this?

Jelly coat receptor

What type of receptor is this?

Resact receptor

What is the acresome?

the vesicle in the sperm that hold digestive enzymes

What is an oocyte

A haploid gamete cell (also known as an egg cell) found in the ovaries

What is a sperm?

A haploid gamete cell found in the testes

What happens when the sperm jelly coat receptors bind to the jelly coat of the oocyte?

This triggers Ca2+ to enter the sperm and make the vesicles sticky

What is bindin

A signal molecule on sperm that will only bind with bindin receptor on the oocyte of the same species (serves as a check that fertilization occurs between the same species)

What is the name of this signaling molecule?

Bindin

What happens when bindin signaling molecule from sperm and bindin receptors on oocyte bindin

This triggers the influx on calcium from the endoplasmic reticulum in the oocyte to be released causing the cortical granules of the oocyte to fuse with the membrane and expand

How do cortical granules prevent polyspermy

1. cleaves bindin receptors

2. layer expands/ swells

What is the mechanism/ structure of the oocyte that helps prevent polyspermy

Cortical granules

What is the structure that is highlighted in the oocyte

Cortical granules

What is gametogenesis?

the process of making gametes (sperm and egg cells)

What is oogenesis?

the process of making oocytes (egg cells)

What is spermatogenesis

the process of making sperm

What is oogonia?

a diploid cell in the ovary that has not gone through meosis 1 yet, it has two fates: to become more oogonia or to become a primary oocyte and eventually an oocyte

What is a primary oocyte?

a diploid cell that has passed the mitosis cell and is destined to be an oocyte but has yet to complete meiosis 1

What is a secondary oocyte?

a haploid cell that has gone through meiosis 1 but has yet to complete meiosis 2

What is a mature ovum?

a mature oocyte, a haploid cell that has gone through meiosis 2

What are polar bodies?

The other product produced in meiosis 1 and 2 that hold genetic information but have too little cytoplasm to become a gamete and thus are destroyed

What are primary polar bodies?

Cells produced in meiosis 1 that hold genetic information but have too little cytoplasm to become a gamete and thus are destroyed

What are secondary polar bodies?

Cells produced in meiosis 2 that hold genetic information but have too little cytoplasm to become a gamete and thus are destroyed

What is the granulosa?

cells attached to the primary and secondary oocyte that provides it nutrients and materials such as RNA

What stages of the oocyte is the granulosa present

at the primary and secondary oocyte

When does mitosis of the oogonia occur

before birth

When does oogonia differentiate into a primary oocyte

before birth

When is meiosis 1 completed and the primary oocyte becomes the secondary oocyte?

during puberty

When is meiosis 2 completed and the secondary oocyte becomes a mature ovum

during fertilization

What is spermatogonia

a diploid cell in the testes that has not gone through meosis 1 yet, it has two fates: to become more spermatogonia or to become a primary spermatocyte and eventually a sperm

What is a primary spermatocyte

a diploid cell that has passed the mitosis cell and is destined to be a sperm but has yet to complete meiosis 1

What is a secondary spermatocyte?

a haploid cell that has gone through meiosis 1 but has yet to complete meiosis 2

What is a spermatid

a haploid cell that has gone through meiosis 2 but has not yet differentiated to become a sperm cell

What must happen for spermatids to become sperm

they must differentiate to become sperm

When are primary spermatocytes first made

during puberty

When are secondary spermatocytes first made

during puberty

When do spermatids start being made and differentiating into sperm

during puberty

When in spermatogonia made

before birth

What is a cytoplasmic determinant?

gene regulatory molecules in the oocyte that are asymmetrically distributed within the cell and promotes differentiation into specialized cells

What are the two mechanisms for cell differentiation

cytoplasmic determinant (bicoid) and induction (neurulation)

How does cytoplasmic determinant work?

it’s asymmetrically localized within the oocyte so that when the fertilized oocyte divides the CD is unevenly distributed among the daughter cells

What is bicoid

a CD that established anterior/posterior or where the head/tail form

high concentrations of bicoid form…

a head

low concentrations of bicoid form…

a tail

What is induction

cells receive signals from other outside cells that prompts receiving cell to differentiate into a specific type of cell
Ex: neurulation

What is the difference between cell differentiation in cytoplasmic determinant and induction (neurulation)

neurulation requires signaling and receptors, ectoderm must have BMP-4 and noggin receptors to develop skin and neural tissue

What is gastrulation

the forming of the 3 germ tissue layers: ectoderm, mesoderm, endoderm

What is ectoderm

outside tissue layer

What structures does ectoderm develop into

epidermal layer (skin), CNS (neural)

What is the mesoderm

middle tissue layer

What structures does mesoderm develop into

skeletal system, muscular system, circulatory system

What is the endoderm

inner tissue layer

What structures does endoderm develop into

liver, gut, digestive tract, urinary tract

What is noggin

a signal produced by the notochord that promotes the development of neural tissue in the ectoderm

What is BMP-4?

a signal produced by the ectoderm that promotes the development of skin tissue

Does BMP-4 block noggin or noggin block BMP-4?

Noggin blocks BMP-4

Why does the neural tube develop in the middle

because the notochord which produces noggin (signal that promotes neural tissue) is in the middle so noggin in concentrated in the middle so ectoderm cells in the center receive noggin and differentiate into neural tissue

How come skin tissue develops if noggin blocks BMP-4

noggin signal is only concentrated in the center so ectoderm cells on the outside only get BMP-4 signal and become skin cells

What are somites

blocks of tissue in the mesoderm that attach to the notochord and neural tube and develop into vertebrate, ribs, and skeletal muscles

What is totipotent

cells that can become any type of cell

What is pluripotent

cells that can become several types of cells but not any cell

What is determined cell

cell that has one fate but has not differentiated yet

What is a differentiated cell

a fully formed cell that has functions specialized to that type of cell

What is neurulation

the formation of the neural tube