Midterm Flashcards
What is Asexual Reproduction?
Takes one organism to produce and pass on genetic material. 100% of genetic material is passed on, thus the offspring is a copy
- Animal example: Amoeba
What is Sexual Reproduction?
The union of egg and sperm. There needs to be a mating occurring and there is genetic variation (50%/50% per parent)
What is the Biological Paradigm?
The animal that leaves the most genes in the next generation, wins, immortality as in offspring
What is reproduction?
When animals (and plants) give rise to offspring which may consist of a portion of the parent by sexual or asexual reproduction
What is sex?
Reproduction marked by the union of gametes (male sperm, female egg).
However, reproduction can happen with union of gametes (sexual) or without union of gametes (asexual)
What are gonads? What are the male and female gonads?
Reproductive glands that produce “germ cells” which mature into “gametes”
Male gonads are tests (sperm are the gametes)
Female gonads are ovaries (eggs are the female gametes)
How do bacteria reproduce?
Through binary fission (asexual reproduction)
the bacterium grows large then the parent splits and becomes two equal parts
How can bacteria DNA be altered?
Conjugation…with “sex pillus” connector
Conjugation is NOT reproduction, bacteria aren’t replicated but altered
When was the first asexual reproduction?
3.8 billion years ago
When was the first sexual reproduction?
1.5 billion years ago
What species can produce sexually and asexually?
Green Algae
Due to environmental changes, “sex inducer gene” is turned on
What is a phenotype?
An organism’s outward appearance influenced by genes and the environment (the external)
What is a genotype?
An organism’s genetic make up (the internal)
How many chromosomes do humans have?
46 total, 23 pairs (including the 2 sex chromosome and 44 autosomes)
Does asexual reproduction use mitosis or meiosis?
Mitosis
Does sexual reproduction use mitosis or meiosis?
Meiosis
Why during the process of Meiosis is each sperm or egg different?
The process of “crossing over” where genetic material swapped and that causes genetic diversity
What can cause genetic variation?
I. Genetic recombination (crossing over)
II. Spontaneous Mutation, errors
III. Induced by external mutagen
What is genetic recombination (crossing over)?
Meiosis process where the child gets a trait (hair color for example) similar to one of their parents
What are spontaneous mutations?
Errors that occur during replication (extra chromosome - down syndrome)
What are external mutagens that can cause variation?
Radiation, smoking, pollution
What were Charles Darwin’s 5 points on Natural Selection?
- All individuals are born with slight variation
- Some variations are neutral, some deleterious, but some bestow an advantage
- Those animals with an advantage will breed more readily and pass on these advantageous variations
- Survival of the fittest
- Overtime, new species may arise due to variation
What are pros and cons of Asexual Reproduction?
Pro:
- fast and easy
- takes only 1 organism
Cons:
- no genetic variation
What are pros and cons of sexual Reproduction?
Pros:
- Offspring have genetic variation
Cons:
- not fast and easy
- needs a mate
What are genetics?
Genes (blueprint of inheritance)
What are genes?
A linear portion of DNA
A gene codes for a protein
What is a chromosome?
A long strand of DNA made up of many genes
What is Loci?
Known genes are found on a certain chromosome at a certain location or position
What is an allele?
An alternative form of a gene
What is Fertilization?
When specialized gametes (a haploid egg & haploid sperm) come together to form a (diploid) zygote
In humans, which is more expensive egg or sperm?
Egg!
What are polar bodies?
When eggs divide unevenly, and more cytoplasm is placed in a daughter cell. Smaller eggs are known as polar bodies
What are the steps of mammalian fertilization?
- Ovary releases egg
- Egg and sperm meet
- egg travels to fallopian tubes
- Implanted in uterus
How long after egg release, does the egg need to be fertilized? How long can sperm live in a woman’s reproductive tract?
- 12-24 hours
- 5 days
About how many eggs do human females hold?
1-2 million where with each egg loss, the quality of egg decreases
How much sperm do men reproduce?
360 trillion, as of recent times, the quality of male sperm has decreased
What caused the decline in quality of human eggs and sperm?
Mutation
True or false: Even when women go through menopause, men can still produce sperm that can cause pregnancy?
True!
True or false: In meiosis, more sperm is produced than eggs?
True!
True or false: In mammals, females typically produce more offspring than males
False, males typically produce more offspring
True of False: the female track can weed out inferior sperm?
True!
What is the “passive egg fallacy”?
Contradicts the idea that the sperm is the ‘key’ to the egg’s ‘lock’
truth: the egg is in control in choosing which sperm fertilizes the egg
What is external fertilization? What is a species that engages on external fertilization?
When gametes unite outside the female’s reproductive tract
fish! they drop their eggs outside, and a male will come over on top the eggs and release his sperm thus fertilizing the eggs
What are pros and cons for external fertilization?
pros:
- doesn’t have to carry eggs
- may or may not have parental care
- self sufficient
- can have high rates of dispersal
cons:
- many eggs aren’t fertilized
- many eggs are wasted as they are eaten
- dispersed to inappropriate habitats
- need to find water (if amphibians)
- doesn’t know father
What is internal fertilization?
Gametes unite within the body of the inseminated animal (typically in the females)
What insects mate in the air via internal fertilization?
Dragonflies, Lovebugs, Hoverflies
Is a female insect collecting a spermatophore considered internal or external fertilization?
Internal fertilization
Can males species get pregnant?
In the case of seahorses, Yes! the males carry the eggs once the female releases them into the male
What are the pros and cons of internal fertilization?
pros:
- Protected inside female (or male)
- Nutrition more constant
- can know relatedness (maternity & paternity)
- Can place eggs in safe setting
cons:
- highly dependent offspring
- females can be slowed down
What are some dangers of mating?
- can be preoccupied with mating and get hunted (male praire dogs)
- male-male contests (fights between males)
- males can hurt/kill the females (male mallards often drown females)
How is sex determined in birds? Name the chromosome type and which sex determines the offspring sex
ZZ males, ZW females
females decide the sex
How is sex determined in most insect? Name the chromosome type and which sex determines the offspring sex
XY males, XX females
male decide the sex
How is sex determined in grasshoppers and crickets? Name the chromosome type and which sex determines the offspring sex
XO males, XX females
males decide the sex
How is sex determined in butterflies? Name the chromosome type and which sex determines the offspring sex
WW male, WZ female
female decide the sex
What are secondary sex characteristics? and name some
traits that appear during puberty
(breasts, facial hair, muscle mass)
What are primary sex characteristics?
gonads and any anatomical part of internal reproductive system
(penis&balls, vagina)
What are the male and female sex hormones?
Female: Estrogens
Male: Androgens
True of false: sex hormones are synthesized from cholesterol
True!
T or F: Sex hormones are excreted by endocrine glands
True! (through the testes, ovaries, and adrenal)
T or F: Sex hormones controls puberty & reproduction
True!
Where do females produce testosterone?
In the ovaries and adrenal gland
Where do males produce estrogen?
in the adrenal glad
What does estrogen regulate in females?
Regulates secondary sex characteristics:
pubic hair, breasts, menstrual cycle
What does progesterone do?
Regulates menstrual cycle, pregnancy, and growth of the embryo
T or F: Prolactin is a sex hormone
False! but high levels can decrease levels of certain sex hormones
What does prolactin do?
related to maternal care including mammalian milk
regulates the immune system and overall metabolism
What are some male secondary sex characteristics?
deepening of voice, muscles mass, growth spurts, increased energy
T or F: testosterone can improve muscle mass and stamina
True! it is produced endogenously by the body in the male testes (inside the body)
What is called when you have artificial testosterone?
Exogenous testosterone (made outside the body)
What are some negatives of artificial testosterone and other steriods?
- hurt the kidney’s
- hurts your liver
- ligaments and joints degrade
- lower sperm count
T or F: for endogenous testosterone, can heighten sex drive but does not correlate with sex drive
True! sex drive is correlated with external stimulus rather than testosterone
What is the “fragile male” concept?
Name the 3 sources
Developing males are more difficult than females
- more spontaneous abortion, hemorrhaging
- male brain at birth is heavier, more risks with oxygen loss at birth
- more congenital deformities (heart defects)
T or F: baby girls suffer more genetic disorders than males
False! baby boys are more prone to genetic disorders
What are some reasons for the sex ratios to shift?
smoking, pesticides
What is fitness in biology?
the extent to which an organism is adapted to, or is able to produce offspring in a particular environment
What is direct fitness?
Passing on your genes through your offspring
What is indirect fitness?
passing on your genes though your relative’s offspring
What is inclusive fitness?
the sum of indirect and direct, during a life time
What is a mating system?
How many sexual partners does an animal have
What is monogamy?
Male and female have one partner in a breeding season or throughout their life
What are characteristics of a monogamous relationship?
- care for offspring
- provide anti-predator defense
- guard female
What are some monogamous animals?
-swans
- dik-dik
What is polygyny?
One male mating with several females
What is an example of an animal that partakes in polygyny?
Mountain gorillas
What is resource defense in polygyny?
Males fight each other to defend a needed resource like land or food
What is female defense in polygyny?
Males fighting to protect his group of females
Explain Lekking
Lekking is when males come together in one area and once females come to the area, they put on a show for the female to select the best mate. Males do this when they find females to mate, some males are excluded
What animals participate in lekking?
- Black grouse
- Topi
What is polyandry?
Female will mate with two males, but each male mates with just one female
What animal partakes in polyandry?
spotted sandpiper
What is promiscuous mating?
male will mate with many females and a female will mate with many males
What animal is able to change their mating pattern?
Saddleback Tamarins (monogamy & polyandry)
What is the matting pattern for Prairie voles and Montane voles?
Prairie voles are monogamous, Montane moles are polygynous
Why are Prairie voles monogamous?
the voles become connected to each other and become ‘sexually addicted’ through social imprinting
Why are Montane voles polygynous?
They have few receptors that doesn’t get them addicted to sex
What is a Hermaphrodite?
A nonhuman organism that has reproductive gonads of both sexes (ovaries and testes) and may possess the secondary sex characteristics of one or both sexes
What animal is an hermaphrodite?
Earthworm (don’t self fertilize, but nematodes can)
Where did hermaphrodites originate from?
probably evolved from single-sexed (male & female) ancestors
- reduced mobility
- produce higher fitness
What are simultaneous hermaphrodites?
the organism has functioning male and female organs simultaneously
- they can choose which function to use
What animal is a simultaneous hermaphrodite?
Hamlet fish
- switch roles during mating bouts
- prevents cheating
What is Bateman’s principle?
Predicts that females will be limited by their egg production (& resources to make eggs), yet males will be limited only by their access to females or to their eggs
What are serial hermaphrodites?
Go from one sex then it changes to the other at some part in their life
What is it called when an animal is first female then male?
Protongynous
In the example of Bluestreak Cleaner Wrasses, why do they become protogynous?
When the harem male dies, the largest female will start to act like a male within hours and produce sperm and breed in 10 days
What are the two main reasons for sex?
- creates new genotypes
- Increases the resistance to parasites and/or pathogens
What does syphilis affect?
affects brain, heart, eyes, and bones
T or F: the US has the highest STD rates in the industrial world
True! the STDs are becoming resistant to the current antibiotics
T or F: The Zika virus can persist in male semen for several months after onset symptoms
True!
T or F: Ebola virus can persist in male semen for five years and can be passed onto a sexual partner
True!
Why do nuns have more breast cancer?
Since nuns do not get pregnant, nuns estrogens levels are lowered
Why don’t nuns have cervical cancer?
cervical cancer is caused by STD HPV and nuns don’t have sex
T or F: all plants and animals that take part in sexual reproduction, can develop STDs?
True!
What is HIV?
Human Immunodeficiency virus
a retrovirus is a virus that can lead to AIDS
(a retrovirus is a virus that inserts its DNA into a cell, and as a result that cell makes more viruses)
What is parthenogenesis?
A type of asexual reproduction where offspring arise from an unfertilized egg
What is the reason for organism to partake in parthenogenesis type of reproduction?
- means to overcome low population numbers
- means to get through difficult environmental condition
T or F: Wild mammals can reproduce parthenogentically.
False! genomic imprinting prevents parthenogenesis (regulating gene expression)
What animals partake in normal parthenogenesis?
(unfertilized egg develops into female)
Amazon Mollies (unfertilized egg develops into female)
What is cyclic parthenogenesis?
an animal alternates between parthenogenesis and sexual reproduction
What is exceptional parthenogensis?
Unfertilized eggs usually die, but sometime they do develop and hatch out
What is facultative parthenogenesis?
eggs develop when they are fertilized (sexual reproduction) and when they are not fertilized
Which organism is an example of cyclic parthenogenesis?
(sexual reproduction occurs late summer rest is parthenogenetic)
Aphids (sexual reproduction occurs late summer rest is parthenogenetic)
which animal is an example of exceptional parthenogenesis?
Bonnethead Shark (shark pup was a female without any male contribution)
What animal is an example of exceptional parthenogenesis?
Komodo Dragon
What animal is an example of faculative parthenogenesis?
parthenogenesis is utilized even when males are available
Turkeys (eggs can develop when they are fertilized and when they are not)
- parthenogenesis is utilized even when males are available
T or F: in the stick insect species, the females prefer to reproduce parthenogenetically
True!
What is a clone?
A clone is an individual that has developed from a single somatic cell from a parent
What is a mosaic?
from one ferilized egg, there arises two distinct populations of cells with different genotypes
occurs when different cells emerged from the same zygote
What is inbreeding?
Breeding with close relatives which often result in a higher frequency of deleterious genes
How do some animal species avoid inbreeding?
- different “senses” recognize kin
- not advantageous
What is the Prepubertal Interaction Theory?
When children play together before puberty, they then lack sexual attraction between each other in their adult lives
T or F: temperature can impact incubation and sex
True! (Australian Skink)
What are the major selection pressures?
I. food
II. Predator Avoidance
III. Find Mates
IV. Disease
What is sexual selection?
One genotype (either a male or a female) mates more frequently because it is deemed more desirable than another genotype
T or F: Sexual selection can produce characteristics that are not vital for survival but assist in attracting a male
True! case of long tail feathers, bright colors
What is OSR?
Operational sex ratio (ratio of breeding males & females)
What is Intrasexual competition?
(within the same sex)
One sex competes with its rival and winner has access to all females
(big strong males win)
What is Intersexual competition?
(between sexes)
Mate choice = female choice, males make themselves attractive to the opposite sex
(female picks the most attractive male)
T or F: ornaments are a sign of quality and good health
True! the brighter they are, the healthier they are
What is the “sexy son hypothesis”?
Females will get with attractive males anf their sons will also be attractive
T or F: females are typically the limiting sex
True! egg is very expensive to produce, thus males will compete to have that expensive female egg
What is an exception of Bateman’s principle?
Sperm is expensive, Male adder snakes lose body mass and needs to rest to produce more sperm
What is the runaway selection hypothesis?
A trait may be slightly helpful for surivial, but if a female likes the trait they will mate with the male and have sons that have the trait, but eventually trait will become disadvantageous (long tail)
What is the Handicap Principle and who coined the term?
Zahavi
a trait may be a burden and therefore it is costly to the bearer. Only a superior animal is able to carry the handicap
(ex: handicap with peacocks with longer tail vs inferior male with small tail)
What is an example of the handicap principle?
Elks with massive antlers, peacocks with long tails (these are handicaps, but they are the superior males)
What is the honest signaling theory?
Animals don’t usually fight to the death, in place is a system where animals signal their aggression, intent, and fighting abilities
Why can’t animals cheat and claim to be the superiors?
- burdensome trait can’t be carried by a weak individual
- If called out to a challenge, could die since you don’t have the skills to defend yourself
- animals look holistically for another superior traits
What is social signaling in humans?
displays of wealth, efforts to hide poverty
What are the male tactics to mate with females?
I. sneaker males & pretending to be female
II. Giving gifts
III. unusual male tactics
IV. sperm competition
V. penis morphology
What is the sneaker male strategy?
male will be percieved as female which gives them access to females and fertilize their eggs (common in fish, Bluegill sunfish)
What is the testes size of the sneaker male compared to other males?
sneaker male bodies are smaller but the size of the testes are larger than other breeding males
What is spermatophore?
a mass package that contains sperm that the females can accept and place into her oviduct
What are nuptial gifts?
Includes spermatophores, and other gifts that do not contain sperm like dead insects, silken balloons, saliva
What nuptial gift does the Empidid fly produce?
silken balloon
What is an example of an unusual male tactic?
Australian redback spider, stands on head and launches himself into the jaws of female that eats him (his body is the gift)
inserts female with sperm
How do sperm competitions work?
needs 2 or more males for the competition
- give more sperm than the other male
- have higher quality sperm than other
- the order of mating
- remove sperm from previous male
- kamikaze sperm (“A” blocks other sperm, “B” attacks and maim other sperm)
Talk about how sperm can cooperate with each other in the reproductive track
Sperm and link up and push each other further up to the egg, then separate where its a one on one battle
What are the female tactics?
I. Access to food (male can become “the food”)
II. Picking a good mate
III. Post copulatory
IV. and Unusual tactics
What species is the female known to eat their male mate?
Black Widows, Praying Mantis
How do male praying mantis’ mate?
- through regular copulation
- if his head is eaten, his body can still position itself over the mate and inseminate her
What is a benefit of the female praying mantis eating the male?
the female gets additional nutritional benefit and can lay even more healthier eggs
How do female Australian Painted Dragons choose a mate?
A female will preference to mate with both the yellow male and red male to maintain variation
What is ovulation?
Occurs when a mature egg is released (an ovum) and is available for fertilization by the sperm
What is the ovulation rate of a chicken?
everyday
What is the ovulation rate of lemurs?
once a year (reason they may go extinxt)
What is the ovulation rate of Meadow Voles?
4 times a year
What is the ovulation rate of Yellow Baboons?
every month
When do Cheetah’s ovulate?
When females heat the “stutter-bark” they get turned on and that initiates ovulation
What are some ovulation signal carried by primates?
Bottom swelling from Baboons
From female tactics, what is an example of female-female competition?
For gorillas, one female of the harem would direct all the male attention onto her so the other females leave the harem
Explain the anovulatory cycle in female cycle?
Females mate with mates without ovulating in order to protect eventual offspring
What is the “father at home” hypothesis?
Males will keep having sex with the female, as eventually she will be ovulating.
T or F: Menstruation has an adaptive benefit
True!
- adaptive spiral artery
- menstrual blood lack clotting factors
What is cuckoldry?
A male raises an offspring that he did not sire
- a female can also be tricked into raising an offspring that is not hers
What animal did cuckoldry stem from?
Cuckoo Bird
What is menopause?
a ceasing of ovulation and menstruation. marked lowering of the production of female hormones
Why is it that the maternal grandmother would take over the grandchild than the paternal grandmother?
the maternal grandmother knows there is direct relatedness, but the paternal grandmother has doubts
What is bacterial conjugation?
by which one bacterium transfers genetic material to another through direct contact (like build a bridge in order to transfer information)
What species participates in external fertilization?
Frogs and Fish
- For frogs, the males will climb onto of the female, and once she releases her eggs the man drops his sperm on the eggs
What animals engage in internal fertilization?
All mammals, sea turtles
T or F: males and females are similar for the first 7 weeks
True!
Explain all the possibilities of the how the position of gerbils in their sack impact level of testosterone.
2M gerbil male: very aggressive, more battle wins, more mating, doesn’t care for offspring
2F male: not aggressive, less mating, women aren’t attracted, cares for offspring
2M female: mature later, more aggressive, prone to fighting
0M or 1M: mature earlier, has more offspring
What does Oxytocin do?
hormone affects sexually receptivity, Related to maternal nurturing behavior
What does Vasopressin do?
In the male brain works to regulate memory formation and is used as a reward in mate bonding (memory of mating)
What happens if the Vasopressin is knocked out?
animals can not recognize or remember each other.
Name a sneaker male
Bluegill sunfish
What type of serial hermaphrodite is male first then female
Protandrous
What is the Red Queen Arms Race?
species must continually evolve new adaptations in response to evolutionary changes in other organisms to avoid extinction.
What is a Barr Body?
inactivated X chromosome
How does the “pill” work as a contraceptive?
The pill makes the body seem like it is pregnant so eggs aren’t released.
