Genetics and Developmental Biology

Animal development compares to plant development in that

Animal development compares to plant development in that

Animal development compares to plant development in that   
A) plant cells, but not animal cells, undergo convergent extension.
B) animal cells, but not plant cells, migrate during morphogenesis.
C) plant cells and animal cells mi

ppk   2188   1 Reply

bio_man

Thalidomide, now banned for use as a sedative in pregnancy, was used in the earl

Thalidomide, now banned for use as a sedative in pregnancy, was used in the earl

Thalidomide, now banned for use as a sedative in pregnancy, was used in the early 1960s by many women in their first trimester of pregnancy. Some of these women gave birth to children with arm and leg deformities, suggesting that the drug most likely

ppk   1980   1 Reply

bio_man

Although it contributes no cells to the embryo, the formation of the primitive s

Although it contributes no cells to the embryo, the formation of the primitive s

Although it contributes no cells to the embryo, the formation of the primitive streak is guided by the structure known as the   

A) neural crest.      B) endoderm.      C) hypoblast.    &n

ppk   1538   1 Reply

bio_man

An open space within the gastrula is the

An open space within the gastrula is the

An open space within the gastrula is the   
A) endoderm.
B) mesoderm.
C) ectoderm.
D) neural crest cells.
E) archenteron.

ppk   2872   1 Reply

bio_man

In frog embryos, the blastopore becomes the

In frog embryos, the blastopore becomes the

In frog embryos, the blastopore becomes the     
A) anus.      B) ears.      C) nose.      D) mouth.      E) eyes.

ppk   2452   1 Reply

bio_man

The outer-to-inner sequence of tissue layers in a post-gastrulation vertebrate e

The outer-to-inner sequence of tissue layers in a post-gastrulation vertebrate e

The outer-to-inner sequence of tissue layers in a post-gastrulation vertebrate embryo is   
A) ectoderm ? mesoderm ? endoderm.
B) endoderm ? mesoderm ? ectoderm.
C) mesoderm ? endoderm ? ectoderm.
D) endoderm ? ectoderm

ppk   3550   1 Reply

bio_man

During the early part of the cleavage stage in frog development, the rapidly dev

During the early part of the cleavage stage in frog development, the rapidly dev

During the early part of the cleavage stage in frog development, the rapidly developing cells     
A) skip the mitosis phase of the cell cycle.
B) skip the cytokinesis phase of the cell cycle.
C) rapidly increase the volume a

ppk   2230   1 Reply

bio_man

From earliest to latest, the overall sequence of early development proceeds in w

From earliest to latest, the overall sequence of early development proceeds in w

From earliest to latest, the overall sequence of early development proceeds in which of the following sequences?     

A) acrosomal reaction ? cortical reaction ? synthesis of embryo's DNA begins ? first cell division

ppk   3013   1 Reply

bio_man

In sea urchins, the "fast block" and the longer lasting "slow block" to polyspe

In sea urchins, the "fast block" and the longer lasting "slow block" to polyspe

 In sea urchins, the "fast block" and the longer lasting "slow block" to polyspermy, respectively, are     
A) the jelly coat of the egg and the vitelline membrane.
B) inactivation of the sperm acrosome.

ppk   2814   1 Reply

bio_man

If gastrulation was blocked by an environmental toxin, then

If gastrulation was blocked by an environmental toxin, then

If gastrulation was blocked by an environmental toxin, then   
A) the blastula would not be formed.
B) the blastopore would form above the gray crescent in the animal pole.
C) cleavage would not occur in the zygote.
D) fertil

ppk   2736   2 Replies

ppk

Compared to sea urchin eggs, those of mammals

Compared to sea urchin eggs, those of mammals

Compared to sea urchin eggs, those of mammals     
A) have not already completed meiosis at the time of ovulation.
B) have no requirement for the cortical reaction.
C) complete the fertilization process more rapidly.
D)

ppk   1386   1 Reply

bio_man

A human blastomere is

A human blastomere is

A human blastomere is     
A) an embryonic structure that includes a fluid-filled cavity.
B) that part of the acrosome that opens the egg's membrane.
C) a cell that contains a (degenerating) second polar body.

ppk   2227   1 Reply

bio_man

As cleavage continues during frog development, the size of the blastomeres

As cleavage continues during frog development, the size of the blastomeres

As cleavage continues during frog development, the size of the blastomeres     
A) decreases as the number of the blastomeres decreases.
B) increases as the number of the blastomeres stays the same.
C) increases as the

ppk   2166   1 Reply

bio_man

At the moment of sperm penetration, human eggs

At the moment of sperm penetration, human eggs

At the moment of sperm penetration, human eggs     
A) have used flagellar propulsion to move from the ovary to the oviduct.
B) have a paper-thin cell of calcium carbonate that prevents desiccation.
C) are still located

ppk   2231   2 Replies

bio_man

In mammalian eggs, the receptors for sperm are found in the

In mammalian eggs, the receptors for sperm are found in the

In mammalian eggs, the receptors for sperm are found in the

A) cytosol of the egg.
B) nucleus of the egg.
C) zona pellucida.
D) fertilization membrane.
E) mitochondria of the egg.

ppk   4474   1 Reply

bio_man

Fertilization normally

Fertilization normally

Fertilization normally     
A) follows gastrulation.
B) is required for parthenogenesis.
C) precedes ovulation.
D) merges two diploid cells into one haploid cell.
E) reinstates diploidy.

ppk   5314   1 Reply

bio_man

In mammals, the nuclei resulting from the union of the sperm and the egg are fir

In mammals, the nuclei resulting from the union of the sperm and the egg are fir

In mammals, the nuclei resulting from the union of the sperm and the egg are first truly diploid at the end of the     

A) acrosomal reaction.
B) activation of the egg.
C) initial cleavage.
D) completion of g

ppk   2057   1 Reply

bio_man

In a newly fertilized egg, the vitelline layer

In a newly fertilized egg, the vitelline layer

 In a newly fertilized egg, the vitelline layer     
A) reduces the loss of water from the egg and prevents desiccation.
B) opens the egg's nuclear membrane to allow haploid sperm DNA to enter.
C) hardens to form a

ppk   2671   1 Reply

bio_man

A reproductive difference between sea urchins and humans is

A reproductive difference between sea urchins and humans is

A reproductive difference between sea urchins and humans is 
A) sea urchin eggs and sperm are of equal size, but human eggs are much bigger than human sperm.
B) sea urchins, but not humans, have a need to block polyspermy because only

ppk   5806   1 Reply

bio_man

Contact of a sea urchin egg with signal molecules on sperm causes the egg to und

Contact of a sea urchin egg with signal molecules on sperm causes the egg to und

Contact of a sea urchin egg with signal molecules on sperm causes the egg to undergo a brief     
A) vitellogenesis.
B) mitosis.
C) acrosomal reaction.
D) membrane depolarization.
E) apoptosis.

ppk   2016   1 Reply

bio_man

During fertilization, the acrosomal contents

During fertilization, the acrosomal contents

During fertilization, the acrosomal contents     
A) help propel more sperm toward the egg.
B) trigger the completion of meiosis by the sperm.
C) nourish the mitochondria of the sperm.
D) digest the protective jelly coat

ppk   4106   1 Reply

bio_man

The vitelline layer of the sea urchin egg

The vitelline layer of the sea urchin egg

The vitelline layer of the sea urchin egg     
A) releases calcium, which initiates the cortical reaction.
B) has receptor molecules that are specific for binding acrosomal proteins.
C) is outside of the fertilization membran

ppk   2939   1 Reply

bio_man

A sea urchin zygote undergoes its first cell division

A sea urchin zygote undergoes its first cell division

A sea urchin zygote undergoes its first cell division     
A) 30 minutes after fertilization.
B) 5 seconds after fertilization.
C) 4 hours after fertilization.
D) 90 minutes after fertilization.
E) 24 hours af

ppk   2405   1 Reply

Jeffrey

As an embryo develops, new cells are produced as the result of

As an embryo develops, new cells are produced as the result of

As an embryo develops, new cells are produced as the result of
A) cell division.
B) morphogenesis.
C) epigenesis.
D) preformation.
E) differentiation.

ppk   2275   1 Reply

star

The formation of the fertilization membrane requires an increase in the availabi

The formation of the fertilization membrane requires an increase in the availabi

 The formation of the fertilization membrane requires an increase in the availability of     
A) hydrogen ions.
B) bicarbonate ions.
C) calcium ions.
D) sodium ions.
E) potassium ions.

ppk   3552   2 Replies

duddy

A human zygote undergoes its first cell division

A human zygote undergoes its first cell division

 A human zygote undergoes its first cell division     
A) 30 minutes after fertilization.
B) 4 hours after fertilization.
C) 5 seconds after fertilization.
D) 24 hours after fertilization.
E) 90 minutes after

ppk   3108   1 Reply

bio_man

Describe the embryonic development of the nervous system.

Describe the embryonic development of the nervous system.

Describe the embryonic development of the nervous system.

ppk   1011   1 Reply

bio_man

Even in the absence of sperm, metabolic activity in an egg can be artificially a

Even in the absence of sperm, metabolic activity in an egg can be artificially a

Even in the absence of sperm, metabolic activity in an egg can be artificially activated by

A) exposure to the low pH of the uterus.
B) abnormally high levels of carbonic acid in the cytosol.
C) abnormally low levels of extracell

ppk   2338   2 Replies

duddy

Fertilization of an egg without activation is most like

Fertilization of an egg without activation is most like

Fertilization of an egg without activation is most like
A) resting during halftime of a basketball game.
B) dropping a rock off a cliff and watching it land in the valley below.
C) walking to the cafeteria and eating lunch.
D) pla

ppk   2322   3 Replies

Jermain_

Contact of a sperm with signal molecules in the coat of an egg causes the sperm

Contact of a sperm with signal molecules in the coat of an egg causes the sperm

4) Contact of a sperm with signal molecules in the coat of an egg causes the sperm to undergo

A) vitellogenesis.
B) apoptosis.
C) depolarization.
D) mitosis.
E) the acrosomal reaction.

ppk   3068   2 Replies

duddy

What function(s) is/are associated with the basal ganglia? Huntington's disease

What function(s) is/are associated with the basal ganglia? Huntington's disease

What function(s) is/are associated with the basal ganglia? Huntington's disease affects the cerebral basal ganglia, causing neural degeneration, and resulting in abnormal muscle movements and cognitive decline. What may cause the cognitive decli

ppk   1773   1 Reply

star

In humans, identical twins are possible because

In humans, identical twins are possible because

In humans, identical twins are possible because     
A) the gray crescent divides the dorsal-ventral axis into new cells.
B) extraembryonic cells interact with the zygote nucleus.
C) cytoplasmic determinants are distrib

ppk   3601   2 Replies

mrjohnston

The term applied to a morphogenetic process whereby cells extend themselves, mak

The term applied to a morphogenetic process whereby cells extend themselves, mak

The term applied to a morphogenetic process whereby cells extend themselves, making the mass of the cells narrower and longer, is     

A) elongational streaming.
B) convergent extension.
C) bi-axial elongation.

ppk   2822   2 Replies

mrjohnston

Candace is a normal-looking 15-year-old girl but has never had a menstrual perio

Candace is a normal-looking 15-year-old girl but has never had a menstrual perio

Candace is a normal-looking 15-year-old girl but has never had a menstrual period, though she has other signs of puberty such as breasts and pubic and axillary hair. During a pelvic exam her physician determines that she has no uterus. Blood tests re

ppk   3543   2 Replies

star

bio

bio

 The nematode Caenorhabditis elegans ____________.
A) is composed of approximately 1,000 cells, for which the developmental origin of each has been mapped.
B) is composed of a single cell in which the developmental origin of each protein h

blonde101   1634   2 Replies

Maria

Do first generation chimeras transmit genes from both parental strains?

Do first generation chimeras transmit genes from both parental strains?

So this is very simple: I made injections of 1 engineered chromosome into Bl6 blastocysts, and I got my chimeras. I will next check for germline transmission on males, but my question is, does chimeric sperm also contain the Bl6 genetic background, o

Binah   1095   3 Replies

duddy

For most animals the vegetal pole of the zygote differs from the animal pole in

For most animals the vegetal pole of the zygote differs from the animal pole in

For most animals the vegetal pole of the zygote differs from the animal pole in that
   A the blastomeres originate only in the vegetal pole.
   B the vegetal pole has a higher concentration of yolk.
   C the posterior end of the embryo for

iwtin1   1995   1 Reply

duddy

Hans Spemann's Experiments

Hans Spemann's Experiments

What are the current time advantages and benefits from the Hans Spemann's Experiments on Embryos ?

Akash Raza   2646   1 Reply

star

Which of the following terms best describes the place in a cladogram where a lineage splits?

Which of the following terms best describes the place in a cladogram where a lineage splits?

Q1. Which of the following terms best describes the place in a cladogram where a lineage splits?

Node
Branch
Root
Tip

Q2. (Hodges and his colleagues hypothesized that evolution of which of the following char

gh1991   28488   1 Reply

duddy

genetic tree

genetic tree

a) Which character, if removed, would
have no effect on tree length?
Character IV
b) Which character provides a synapomorphy supporting the Hoelzerium/Hardassensis clade? Character II
c) Cynthiae+Moorehelpus are often lumped toget

gh1991   1542   3 Replies

bio_man