Log in
HomeStudy Guides420,000US230,000

BIOLOGY 280 Midterm: Review 6_done

8 views4 pages
lavendersnail893
16 Nov 2020
School
UMASS-Amherst
Department
Biology
Course
BIOLOGY 280
Professor
Bruce Byers

For unlimited access to Study Guides, a Grade+ subscription is required.

Document Summary

Describe the logic underlying trivers" theory that anisogamy (and more broadly asymmetrical parental investment) results in sexual selection. Anisogamy is sexual reproduction by the fusion of two dissimilar gametes (difference size and types). In broader terms, it is the differential parental investment. In most cases, the female investment is much greater than the males and in large terms, it is because of the difference in sperm and eggs. The differential parental investment is due to difference in size of gametes. For example, female birds may lay eggs that"s almost 1/3 of her own body weight and full of nutrients, whereas the males" sperm is an individual cell. For mammals, the female will carry the offspring in their body for months and nurse them for a while after birth. Males only need to provide one sperm to fertilize the egg. By looking at gametes, females have less that are more expensive while males have a many cheap gametes.

Get access

Grade+
$40 USD/m
Billed monthly
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
10 Verified Answers

Related Documents

BIOLOGY 280
Final Exam
Study Guide
BIOLOGY 280 Study Guide - Final Guide: Facial Symmetry, Mate Choice, Symmetry In Biology
lavendersnail893
BIOLOGY 280 Lecture Notes - Lecture 11: Guppy, Sensory System, Reproductive Isolation
amaranthmarten130
BIOLOGY 280
Final Exam
Study Guide
BIOLOGY 280 Study Guide - Midterm Guide: Hybrid Speciation, Heteroneura, Reproductive Isolation
lavendersnail893

Related Questions

Please briefly explain reasoning for all questions.

1)

Which of the following is a component of a vertebrate kidney? (Select all correct choices.)
glomerulus
Bowman's capsule
renal tubules
collecting ducts
Malphigian tubules

2)

In organisms, the ability to control osmosis depends on the properties of the plasma membranes of individual cells. Based on their ability to permit the free movement of water and some solutes, these membranes are best described as: (select all correct choices)
impermeable.
permeable.
semipermeable.
diffusible.
impervious.

3)

True or false: The inner cell mass of the blastocyst becomes the embryo, while the outer cell layer of the blastocyst forms part of the placenta.
true
false

4)

Which of the following accurately characterizes the early cleavage divisions in most animals, although not necessarily in mammals?
They do not involve an increase in the size of the zygote.
They are directed by the zygote’s genome.
They are relatively slow.
They do not occur at the same time, so at any given moment the zygote may have an odd number of cells.
All of these choices are correct.

5)

A key difference between hormonal regulation of the reproductive systems of males and females is that:
LH and FSH are released only in females.
LH and FSH are released only in males.
LH and FSH are released cyclically in females but nearly continuously in males.
LH is released in males and FSH is released in females.
LH is released continuously in males and FSH is released cyclically in females.

6)

Compared to sexual reproduction, asexual reproduction: (select all correct choices)
requires less investment in attracting mates.
allows much more rapid population growth.
is rarely found as the sole mechanism of reproduction.
results in the production of genetically identical cells or individuals.
involves meiosis and fertilization as core processes.

7)

True or false: In response to LH and FSH, ovaries secrete estrogen and progesterone.
true
false

8)

During the luteal phase of the menstrual cycle, if the oocyte is not fertilized, a number of events occur which are listed below. Select the answer that places the events in the correct chronological order.

Events:
1. the lining of the uterus is shed
2. the corpus luteum secretes progesterone
3. follicle cells are converted to the corpus luteum
4. the corpus luteum degenerates
5. estrogen and progesterone levels fall

3, 2, 4, 5, 1

1, 2, 3, 4, 5

2, 4, 3, 1, 5

4, 3, 2, 1, 5
5, 2, 3, 4, 1

9)

If an antibody is missing its Fc fragment, what would happen if this antibody encounters its target antigen in the bloodstream? Select all correct choices.
The antibody would be able to bind the antigen at a specific epitope.
The antibody would be able to bind the antigen, but not at an epitope site.
The antibody would not be able to bind to the antigen.
The antibody would be able to activate components of the complement system.
The antibody would not be able to activate components of the complement system.

10)

If an individual carries a mutation that results in a complete lack of MHC class I proteins, how would the individual’s immune response be affected? Select all correct choices.
Memory cell antibodies would not be able to attach to antigen epitopes.
Cytotoxic T cells would not be able to target (and destroy) infected cells.
Helper T cells would not be able to interact with antigen-presenting cells.
Plasma cell antibodies would not be able to attach to antigen epitopes.

11)

If an individual carries a mutation that results in a complete lack of MHC class I proteins, how would the individual’s immune response be affected? Select all correct choices.
Memory cell antibodies would not be able to attach to antigen epitopes.
Cytotoxic T cells would not be able to target (and destroy) infected cells.
Helper T cells would not be able to interact with antigen-presenting cells.
Plasma cell antibodies would not be able to attach to antigen epitopes.

12)

Which of the following statements is true regarding T cell receptors? Select all correct choices.
They recognize antigen-MHC complexes.
They contain variable and constant regions.
They are composed of two heavy (H) chains and two light (L) chains.
They are formed by the rearrangement of V, J, C, and D gene segments.
They can be found in the bloodstream independent of T cells.

PLEASE ANSWER IN PARAGRAPH FORM CORRECTLY. I appreciate it.

1. A) Describe what SexualSelection is and B) explain how it differs fromNatural Selection

2. Research a behavior in an animal andA) explain the ultimate causes of that behaviorand B) list the proximate causes of it.

3. “The southern gastric broodingfrog was discovered in 1972 and properly described in 1981. Intenseinterest followed and in the same year it had disappeared in thewild, shortly followed by the last captive specimen's death in1983. The interest was primarily due to the frog's unusualreproductive method. The female swallows her eggs and turns herstomach into a womb, vomiting up her young when they are grown. Theloss of her stomach means she doesn't eat while they develop, andher new womb bloats so much it causes her lungs to collapse(meaning she has to breathe through her skin). On the other handanother species of frog, the Túngara frog, lay their eggs in a pondand leaves them to develop on their own without any parental care”(www.facebook.com/evolutionarybiology - like). A)Compare the gastric brooding frog and the Túngara in terms of howthey balance the trade-off of quality vs. quantity of offspring(are they each K-selected or r-selected?). B) Whatother life-history traits (include: life span, number of offspringproduced, age at reproduction, reproductive events per lifetime) doyou expect to find differences between gastric brooding frog or theTúngara frog? Explain.

4. A) Explain why one can argue that humanswere K-selected species before the industrial revolution and now inmodern times see to be r-selected (in your explanation include theterms: carrying capacity, rate of population growth).B) However, in developed countries, the number ofoffspring produced per couple is decreasing every year, the age offirst time mothers in increasing (they are older when they havetheir first baby) and the cost of investment per offspring isincreasing (for example college tuition!). Explain what effectwould that have in the model of population growth in developedcountries (do you expect them to be more K-selected or r-selected?)Make sure to support your argument. C)Can human population increase forever? (use the terms: carryingcapacity, population growth, density-dependent anddensity-independent factors).

5. Study the figure below (published in Kwanoet al. 2002). The x-axis of the figure shows different locations atdifferent altitudes, with altitude decreasing from left to right(W. Java has the highest altitude, W. Mindanao has the lowest). They-axis represents the range of body length for beetles found ateach location. Two species of closely related rhinoceros beetlesinhabit Southeast Asia: Chalcosoma caucasus andChalcosoma atlas. One species, C. atlas (whiteboxes in the figure), is more common in low altitude, while C.caucasus (filled boxes in the figure) is more common in higheraltitudes. However, they overlap at intermediate altitude (fromLampung to E. Thailand). The graph shows the body length of eachspecies in allopatric and sympatric locations. What ecologicalphenomenon can explain the differences between the allopatric (whenonly one species lives in that location) and sympatric (when bothspecies live in the same location) populations? Please explain yourargument, you MUST include the terms: competition, competitiveexclusion, realized niche, fundamental niche, resource-partitioning& character displacement).

Andrea Smith was taking notes for her biology exam. Her professor has told her that the exam would cover, in part, the di erences between sexual and asexual reproduction. As she reviewed her notes and prepared for today’s class, she was thinking about her own reproductive dilemma. If only asexual reproduction were the case for humans, maybe she wouldn’t be in this mess. Or at least there wouldn’t be questions about who was the father of her twins. “Dwelling on it isn’t going to help me prepare for class, and right now I have got to nish this chapter on animal reproduction,” she thought. She tried to concentrate and forget about her current dilemma as she feverishly typed on her notepad:

Asexual or sexual reproduction: 3 types of asexual reproduction: (1) ssion: separation of a parent organism into two or more individuals of equal size, (2) budding: growth of new individuals from outgrowths of existing organisms, and (3) fragmentation accompanied by regeneration: the breaking of the body into several pieces, some or all of which develop into new complete individuals through the regrowth of lost body parts. NOTE: Be able to explain the di erences between sexual and asexual reproduction!

She suddenly let out a long sigh. “It’ll be ne,” she thought. “I just hope that none of my family or friends watches the show. What was I thinking when I agreed to this? But that’s what Xavier wanted, and I will do whatever it takes to prove he is the father. Besides I am going to need the money if I have to take care of these babies on my own!”

e next day in class she was feeling even more nervous and was becoming increasingly angry as she thought about her current situation. Her thoughts were interrupted by the sound of her professor’s voice:

“OK, class,” her teacher was saying, “that wraps up asexual reproduction. Let’s move on to reproductive cycles
and patterns. Most animals exhibit cycles in their reproductive activity. Reproductive cycles are often controlled
by hormonal and environmental cues. Animals may reproduce either exclusively asexually or sexually while other animals alternate between the two methods. For example, some animals can lay eggs of two types, depending on
the environment and/or season. One egg type matures only if it is fertilized while the other type does not require fertilization for development, a process called parthenogenesis. Some animals, and in rare cases humans, have both male and female reproductive systems. Some hermaphrodites can fertilize themselves, but most must mate with a member of the same species. Please look over these handouts and answer the questions that follow.”

As the other students read through the assignment, Andrea was thinking: “I’m dealing with a case of sexual reproduction that no doubt started with the fertilization of my egg with, hopefully, Xavier’s sperm. at reminds me, I need to make sure I go over internal and external fertilization again in my notes. I’m not sure I completely understand it.”

All this started the night Xavier had come came over to talk to Andrea about their break-up. He had smelled and looked so good that evening. e events of that night had left Andrea wondering if there was really some truth to that stu about pheromones, which Andrea has learned in her class were chemical signals released by one organism that in uence the behavior of another individual of the same species. Even though Andrea had met someone else and had

“An Unusual Case of Animal Reproduction” by Powell and Tillman Page 1

been seeing Neo for a while, she hadn’t been able to resist Xavier. Neither she nor Xavier had behaved like themselves that night. It was unlike them not to use some barrier method of contraception. As the class wrapped up, Andrea’s mind was still on her upcoming appearance on a daytime talk show. In some ways she was dreading it; but she was determined to prove what she believed she had known all along: at Xavier was the father of her twins.

Questions

1. What is the di erence between asexual and sexual reproduction?
2. List and de ne some types of asexual reproduction. Give one example of each. 3. What is the di erence between parthenogenesis and hermaphroditism?
4. What is the di erence between internal and external fertilization?
5. What is the function of pheromones?

NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE

“An Unusual Case of Animal Reproduction” by Powell and Tillman

Page 2

Part II – The Pregnancy

“I can’t believe it has come to this! Airing our dirty laundry on national television. I never thought Xavier would let things get so out of hand.”

It was late and Andrea was so upset she couldn’t sleep. She tried studying for the upcoming exam, but she couldn’t concentrate. She decided to get an early start on packing. She was so angry with Xavier. How could he have left her pregnant and alone, she thought, as she neatly added her new dress to the bag? How could he think that their babies might belong to someone else? She grabbed her journal, about to add it to the bag, but instead sat in her cozy corner chair and began to read:

January 12, 2007

I’m pregnant with twins! Sometimes it’s still hard to believe because it was so unexpected. I feel like I am about to pop! I know that Xavier is the father of my babies and I can’t wait for us to be a family. But he has doubts about it all because he knows that I met someone else during the brief time that we split up. And he wants to be sure that he is the father before we can move on. But what if it is Neo, the new guy I met? ere’s a slight chance but I doubt it. I know the exact time of conception. It was the night Xavier came over to talk about our relationship. It was a little over a week after that night that the pregnancy test detected the increase in HCG. I guess I just missed him so much.

I do regret that Xavier hasn’t been around much during the pregnancy. He has missed the development of our babies. In the past months, I have heard the babies’ heartbeats and felt them moving around. I wish he would come back because it’s obvious that I am pregnant now. Hopefully we can talk through our di erences and get back together before the pregnancy gets di cult—the frequent urination and back pain my OB/GYN keeps warning me about. I know there is no way he will ever let me go through labor alone. I only pray the contractions are not more than I can bear. Xavier seems committed to the idea of a paternity test. Hopefully it won’t come to that, but if it does, we’re going to a daytime show to gure all this out.”

“Wow! at seems like a lifetime ago,” she thought. “Now we have these beautiful twins and we don’t seem any closer to becoming the real family I dreamed about. Well this will all be over in a couple of days. I am 110% con dent that the twins belong to Xavier, not Neo. I can’t wait to see the look on Xavier’s face and hear him apologize once he sees the results of the paternity test!”

Questions

1. What does Andrea mean by time of conception?
2. How is HCG used to determine pregnancy?
3. List some changes that occur with the fetus/mother during the 1st, 2nd, and 3rd trimesters. 4. What hormones are responsible for inducing and regulating labor?
5. What trimester is Andrea in during this journal entry?

NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE

“An Unusual Case of Animal Reproduction” by Powell and Tillman

Page 3

Part III – The Results

Andrea replayed the words over and over again in her mind: “Xavier, you ARE the father!” She was ecstatic. Finally, she could breathe, knowing that Xavier was the father of her babies. en she heard what the host had to say next...

“Neo...YOU ARE the father!”
Andrea looked around in disbelief. She heard herself saying, “What do you mean? You just said Xavier was the father!

If Xavier is the father, how can he be the father?” she asked as she pointed toward Neo.

“Well, this is a rst, even for our show. But it appears that your twins were fathered by both of these men.”

“I can’t believe it. e rst time I do something like this and I end up with twins and two fathers! Not only did I expose myself to potentially deadly STDs, but now I have two children, whom I have no doubt that I will be raising alone, and I have put my school career in jeopardy,” Andrea thought.

She still couldn’t believe this was really happening to her. How was it possible that her TWINS have di erent fathers? What were the events that must have happened within her body that could lead to these circumstances? She grabbed her

journal from her bag and ipped back to the entry describing her feelings the day she found out she was having twins:

August 23, 2006

I just came back from another Dr’s appointment. Dr. Blossom informed me that I am having two babies— twins—fraternal. I don’t know if they are boys or girls yet. One could be a boy and the other a girl. I still can’t believe this has happened. Xavier has to be the father. He has to be! I will have to just play the hand I have dealt myself. How stupid was I? I was going to practice abstinence after Xavier and I broke up...and I certainly wasn’t planning on meeting and getting involved with Neo! I can’t believe that Neo and I didn’t use a condom either. And it’s no excuse that we had been drinking. I just got caught up in the moment with Xavier—going down memory lane and things got all sentimental. I could have at least thought to use the rhythm method and kept track of when ovulation may occur. is has to be the most irresponsible thing I have ever done! Why did I stop taking my birth control pills anyway? And I have no idea where I put that diaphragm. Undoubtedly, some people will judge me as the type of woman who should have a tubal ligation that would permanently prevent any pregnancy.

Everything hit her at that very second. She closed her journal and just sat there for a moment. Andrea was reminded that she had stopped taking the pill the month before she became pregnant. She remembered that physicians recommend that a woman wait at least one cycle after she stops taking the pill before becoming pregnant because there is a chance that multiple ovulations may occur. Did it have something to with oogenesis? Andrea was so confused she just couldn’t keep things straight in her mind. She thought about it for a minute to let it all sink in.

Andrea sat back and thought about the lecture on animal reproduction the week before. She pulled out her lecture notes on the menstrual cycle, the basic foundation of everything that she was going through.

Questions

1. Describe the two types of cycles that occur in female mammals (menstrual vs. estrous).

2. Compare and contrast the sterilization techniques (vasectomy and tubal ligation) and the temporary and reversible methods discussed in the case.

3. What are the functions of GnRH, FSH, LH, estrogen, and progesterone?

4. How can the paternity results be explained? Your answer should consider the amount of time before and after ovulation a woman is at risk for pregnancy and how long sperm can survive in the reproductive tract. Your discussion may include the following terms: ova, oogenesis, and fertilization, etc.

•

Image in title block dervied from licensed image © CLIPAREA.com—Fotolia.com, ID #21458691. Case copyright held by the National Center for Case Study Teaching in Science, University at Bu alo, State University of New York. Originally published December 8, 2011. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work.

NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE

“An Unusual Case of Animal Reproduction” by Powell and Tillman Page 4

Andrea’s Lecture Notes: The Female Reproductive Cycle

(I) e female reproductive cycle involves both the uterus and the ovaries:

Menstrual cycle = uterine cycle
• Refers to the speci c changes that occur in the uterus

Ovarian cycle
• Cyclic events in the ovaries that regulate the menstrual/uterine cycle

(II) Hypothalamus secretes gonadotrophin-releasing hormone (GnRH) which stimulates the anterior pituitary to secretefollicle stimulating hormone (FSH) and luteinizing hormone (LH) into the blood. FSH and LH regulate the ovarian cycle.

~OVARIAN CYCLE:

Folicular Phase

FSH and LH stimulate a follicle to grow

e growing follicle releases estrogen

Ovulation

• An LH surge triggers ovulation

Luteal Phase

LH stimulates ruptured follicle to become corpus luteum

Corpus luteum secretes estrogen and progesterone, which inhibits LH and FSH secretion from the pituitary

Corpus luteum disintegrates

Estrogen and progesterone levels decrease, releasing the inhibitory e ect on the hypothalamus and the

pituitary

FSH and LH are released and a new cycle begins

(III) Ovarian hormones, estrogen and progesterone, regulate the uterine (menstrual) cycle ~UTERINE CYCLE:

Proliferative Phase

• increasing estrogen levels causes the uterine lining (endometrium) to thicken: prepares the uterus for

implantation of the blastocyst

Secretory Phase
• increased levels of estrogen and progesterone following ovulation maintains the endometrium by increasing

blood supply and growth of endometrial glands that secretes nutrients

Menstrual Flow Phase
• decreased levels of estrogen and progesterone cause the uterine arteries to spasm, depriving the endometrium

of blood: endometrium disintegrates, resulting in menstruation

Based on the information in the case study, Animal Reproduction, please answer the following questions.

Andrea is pregnant and is trying to calculate the time of conception.What is time of conception and how is it determined?

What are the functions of GnRH, FSH LH, estrogen and progesterone in pregnancy?

Andrea is having twins but the babies have two different fathers.Explain the difference between fraternal and identical twins.Which are these?How could the babies have different fathers?