Genetics and Developmental Biology

Which of the following directors of embryonic development can be found in the un

Which of the following directors of embryonic development can be found in the un

Which of the following directors of embryonic development can be found in the unfertilized egg?
A) tissue-specific proteins
B) proteins in the organizer region
C) cytoplasmic determinants
D) mRNAs from embryonic genome
E

ppk   2416   1 Reply

how_mendel

Which of the following is the most basic process in the developing embryo becaus

Which of the following is the most basic process in the developing embryo becaus

Which of the following is the most basic process in the developing embryo because all of the other processes listed can occur only after it, or in conjunction with it?
A) organogenesis
B) cell differentiation
C) mitosis
D) mor

ppk   2156   1 Reply

how_mendel

Hans Spemann and colleagues developed the concept of the primary organizer in am

Hans Spemann and colleagues developed the concept of the primary organizer in am

Hans Spemann and colleagues developed the concept of the primary organizer in amphibian embryos while studying the     

A) medial cells between the optic cups.
B) anterior terminus of the notochord.
C) dorsal lip

ppk   2508   2 Replies

A

The autonomic nervous system has minimal, if any control of

The autonomic nervous system has minimal, if any control of

7. The autonomic nervous system has minimal, if any control of
a) decreased intestinal peristalsis due to stress
b) muscular co-ordination required to write this exam
c) exam tension causing increased gastric tension
d) dilation o

YMCMB   1463   5 Replies

YMCMB

Consider the following model in answering the following questions.

Consider the following model in answering the following questions.

1)Consider the following model in answering the following questions.
Genotype: A1A1  A1A2  A2A2
Fitness:       1         1      1-s
a) What kind of selection does this model r

gh1991   1026   1 Reply

bio_man

The above events in the sequence in which they occur during the reproductive

The above events in the sequence in which they occur during the reproductive

1) Pre-embryo release hCG, which maintains hormone levels
2) A hormones signals the follicle to rupture
3) Blastocyst is implanted
4) The egg is fertilized to form a zygote
 

kasy110   3490   5 Replies

bio_man

A blastocyst differs from the spherical 16-cell morula in that the blastocyst is

A blastocyst differs from the spherical 16-cell morula in that the blastocyst is

A blastocyst differs from the spherical 16-cell morula in that the blastocyst is a sphere that contains..
a) An inner cell mass with germ layers that nourish the developing embryo
b) An inner cell mass with germ layers that will develop int

kasy110   4074   1 Reply

duddy

The archenteron of the developing frog eventually develops into the

The archenteron of the developing frog eventually develops into the

The archenteron of the developing frog eventually develops into the     
A) heart and lungs.
B) digestive tract.
C) brain and spinal cord.
D) blastocoel.
E) reproductive organs.

ppk   2946   2 Replies

ritamonteiro

Human Reproduction and Development

Human Reproduction and Development

1. Which reproductive structures are least similar in function
a) testes and ovaries
b) ductus deferens and fallopian tube
c) interstitial cells of testes and follicles of ovaries
d) ductus deferens and uterus

2. Some e

YMCMB   995   2 Replies

duddy

Human Reproduction and Development

Human Reproduction and Development

15. Two components in semen that promote the sperms ability to travel to the ovum in the Fallopian tube are
a) fructose and alkaline buffers
b) fructose and testosterone
c) FSH and testosterone
d) FSH and alkaline buffers

YMCMB   747   1 Reply

duddy

Human Reproduction and Development

Human Reproduction and Development

1. The thickening of the uterine wall is caused mainly by
a) LH
b) oxytocin
c) estrogen
d) FSH

2. What is the immediate effect of a high level of leutenizing hormone (LH) on the ovary?
a) delays menstruation
b

YMCMB   1067   2 Replies

duddy

Human Reproduction and Development

Human Reproduction and Development

1. The thickening of the uterine wall is caused mainly by
a) LH
b) oxytocin
c) estrogen
d) FSH

2. What is the immediate effect of a high level of leutenizing hormone (LH) on the ovary?
a) delays menstruation
b

YMCMB   905   1 Reply

duddy

What is the number of deaths due to sickle-cell anemia in a region without mosquitoes expected to be

What is the number of deaths due to sickle-cell anemia in a region without mosquitoes expected to be

Q1. What are alleles?
a)Different forms of the same gene.
b)Different genes.
c)The different characteristics of an organism.
d)Genes found only in humans.

Q2. If you add up the frequency of homozygotes + the frequency o

gh1991   12689   2 Replies

duddy

please help: hardy weinberg and things.. :)

please help: hardy weinberg and things.. :)

1. One factor that can make the effective population size (Ne) differ from the number of breeding individuals is the breeding sex ratio. What is the value of Ne for a population of 5 breeding adult males and 95 adult females? Explain why Ne is differ

gh1991   1507   1 Reply

bio_man

A correct statement is:

A correct statement is:

The correct statement is:   
         A) The ectoderm gives rise to the liver.
    B) The mesoderm gives rise to the notochord.
    C) The endoderm gives rise to the hair follicles.
    D) The mesoder

pmiller8892   2669   3 Replies

patel202

hellpp please on exam samples .. variation genetics

hellpp please on exam samples .. variation genetics

1. Why is genetic variation important in evolution?

2. How does inbreeding increase the strength of genetic drift within families in large populations, and how can this effect be empirically detected?

3. The graph below was prod

gh1991   1138   2 Replies

bio_man

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   1544   3 Replies

bio_man

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   28492   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   2647   1 Reply

star

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

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

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

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   3544   2 Replies

star

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   2823   2 Replies

mrjohnston

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   3603   2 Replies

mrjohnston

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

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

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   2323   3 Replies

Jermain_

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

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   1012   1 Reply

bio_man

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   3110   1 Reply

bio_man

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   3553   2 Replies

duddy

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   2282   1 Reply

star

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   2406   1 Reply

Jeffrey

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   2941   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   4107   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   2017   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   5807   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   2679   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   2060   1 Reply

bio_man